2007 Completo Lotus Newslette
2007 Completo Lotus Newslette
2007 Completo Lotus Newslette
Editor: M. Rebuffo
INSTITUTO NACIONAL DE
INVESTIGACION AGROPECUARIA
Editor: M. Rebuffo
INSTITUTO NACIONAL DE
INVESTIGACION AGROPECUARIA
Editorial Office
INIA La Estanzuela This Newsletter consists of informal
Colonia, Uruguay reports which are presented to further
Phone: +598-574-8000 the exchange of ideas and information
Email: lnl@inia.org.uy between research workers.
Fax No.: +598-574-8012 Consequently the data presented here
Web: http://www.inia.org.uy/sitios/lnl/ are not to be used in publications
without the consent of the authors.
Images are copyright of the authors,
and their reproduction is strictly
prohibited without their consent.
Front cover: Juan Ramón Acebes Ginovés and Felicia Oliva Tejera spoke about the
endemic Lotus species of the Canary Islands (pp. 14-15) at the Workshop: Lotus as a
model legume and a sustainable alternative for marginal land reclamation (Botanic
Garden of the University of Valencia, Spain, September 6-7 2007). The photograph on
the front cover shows flowers of Lotus berthelotii, one of the species from the Canary
Islands. The picture was recorded at the Jardin Mundani, Mallorca, Islas Baleares, Spain,
and authorized by its publication at Lotus Newsletter 37(2) by Juan Bibiloni Pou.
The opinions in this publication are those of the authors and not necessarily those of the
Lotus Newsletter. The designations employed and the presentation of the material in this
publication do not imply the expression of any opinion whatsoever on the part of the
Newsletter concerning the legal status of any country, territory, city, or area, or of its
authorities, or concerning the delimitation of its frontiers or boundaries. Where trade
names are used this does not constitute endorsement of or discrimination against any
product by the Newsletter.
Lotus Newsletter (2007) Volume 37 (2), i-iv.
i
ii
ENTIDADES COLABORADORAS:
UNDER THE SPONSORSHIP OF:
MINISTERIO
DE
EDUCACION
Y
CIENCIA
Cátedra UNESCO de Estudios sobre
el Desarrollo
CONSEJO
SUPERIOR DE
INVESTIGACIONES
CIENTIFICAS
ESTACION
EXPERIMENTAL
DEL
ZAIDIN
iii
Programme
Thursday, September 6
13:15-15:00 Lunch
Friday, September 7
13:30-15:00 Lunch
Session 4: Microbiology
18:45-19:00 Conclusions
Lotus Newsletter. (2007). Volume 37. Number 2.
Contents
Program i
iv
Lotus Newsletter (2007) Volume 37 (2), 52 - 53.
ARNOLDO SANTOS *
Unidad de Botánica-Instituto Canario de Investigaciones Agrarias (ICIA). Jardín de
Aclimatación de La Orotava, Calle Retama 2, 38400 Puerto de la Cruz (Tenerife). Canary
Islands- Spain.
*
Corresponding author click here for Spanish version
Lotus (Fabaceae: Loteae) is a moderate size genus comprising 125 – 180 spp. (Sokoloff and
Lock, 2005). It includes herbs, suffrutices, and small shrubs; some of the species have
ornamental values (i.e., specially the Rhyncholotus group from Canary Islands), others have
broad use as forage (i.e., particularly the L. corniculatus –birdstrefoil-complex, L.
pedunculatus –bigtrefoil- and L. tenuis), and others are used as cosmetics. The tribe Loteae
is closely related to Sesbaniea and Robineae. The genus is composed of several subgenera,
although their boundaries are not clearly understood and additional taxonomic research is
needed at supra-generic level. For instance, the latest edition of Flora Europaea does not
recognize any subgenus and divide the genus into six sections (i.e., Lotus, Erythrolotus,
Krokeria, Lotea, Pedrosia and Quadrifolium). In addition, Flora Europaea considers
Dorycnium as a distinct genus. This taxonomic treatment is also followed by Flora Iberica.
Lotus is mostly confined to the northern hemisphere with a few species in southern one
(South America, Africa and Australia). Flora Europea distinguishes over 30 species in
Europe, and the genus also occurs in North Africa and the Atlantic archipelagos of Azores,
Madeira, Salvajes, Canaries and Cape Verde Macaronesian Islands. Over 20 species are
endemic to these islands. Few species of the genus occur in East Africa, although some of
them are found on high altitudes areas of the Somalia-Masai massif. The Arabia peninsula,
Sokotra, and South Africa have a very limited number of species. This pattern is also found
in the New World, where there are few species on North America, Central America, and/or
South America. Hosackia, a genus previously placed within Lotus, has over 11 species in
SW Canada, W USA, Mexico and Guatemala, although most of them are in California areas.
Among them, Lotus corniculatus and relatives have been the subject of intensive research
because their value as cash-crops. A main limitation for the agriculture exploitation of these
species concerns the presence of cianogenetic compounds, and several research programs
are under development at different countries to explore and increase its use. Nucleotide
sequences of the ITS region of the nuclear ribosomal DNA have been used to obtain
phylogenetic reconstructions. These molecular phylogenies have included species from
North America (Allan and Porter, 2000) and from the Atlantic Islands (Allan et al., 2004). A
recent taxonomic study by Sandral et al. (2006) concerned Lotus section Pedrosia, this study
included all of the Macaronesian species, a selection of the North-western African ones and
two species with a Mediterranean distribution, Lotus arenarius and L. creticus. Recent
taxonomic research has relied mostly on flower, leaves and stipules traits and has been
recently published by Kramina (2006). This recent study has helped to clarify taxonomic
boundaries within the L. angustissimus complex, a taxon mostly found in Eurasia. Types of
Lotus taxonomy 53
indumentum have been tacked in account by Mader and Podlech (1989) to differentiate
marrocan species. Molecular systematic and morphological taxonomy research is currently
been undertaken by Graeme Sandral (Australia), Botanical Gardens Orotava and Viera y
Clavijo at Canary Is., and Isidro Ojeda (Vancouver, Canada). Several projects are trying to
get commercial cultivar(s) that will help to reduce soil water recharge and salinity problems
(Graeme Sandral and collaborators, Australia). Other projects are under development at
Uruguay, Chile and Argentine trying to get a better use of Lotus spp. as forage plants
including nitrogen fixation capacity.
References
ALLAN G.J. and PORTER J.M. 2000. Tribal delimitation and phylogenetic relationships of
Loteae and Coronilleae (Faboideae: Fabaceae) with special reference to Lotus :
evidence from nuclear ribosomal ITS sequences. American Journal of Botany, 87,
1871-1881.
ALLAN G.J., FRANCISCO-ORTEGA J., SANTOS-GUERRA A., BOERNER E. and ZIMMER E.A.
2004. Molecular phylogenetic evidence for the geographic origin and classification of
Canary Island Lotus (Fabaceae: Loteae). Molecular Phylogenetics and Evolution, 32,
123-138.
MADER U. and PODLECH D. 1989. Revision der marokkanischen Arten von Lotus L.
subgen. Pedrosia (R. Lowe) Brand (Leguminosae).- Mitt. Bot. Staatssamml. München.,
28, 513-567.
SANDRAL G., REMIZOWA M.V. and SOKOLOFF D.D. 2006. A taxonomy survey of Lotus
section Pedrosia (Leguminosae, Loteae). Wulfenia, 13, 97-192.
SOKOLOFF D.D. and LOCK J.M. 2005. Loteae. In LEWIS G., SCHRIRE B., MACKINDER B.
and LOCK M. (Eds.). Legumes of the world. BATH Press: United Kingdom. pp.
455-466.
Lotus Newsletter (2007) Volume 37 (2), 54 - 55.
Department of Molecular Biology, University of Aarhus, Gustav Wieds Vej 10, DK-8000
Aarhus, Denmark.
*
Corresponding author
The molecular genetics of Lotus is focused on three diploid species: Lotus japonicus, Lotus
filicaulis and Lotus burttii. In addition to the inbred germplasm of these species a resource of
recombinant inbred lines has also developed from L. filicaulis x L. japonicus ecotype Gifu,
from L. japonicus ecotype Gifu x L. burttii and from L. japonicus ecotype Gifu x L.
japonicus ecotype MG20. In parallel several methods for genetic analysis of gene function
have been established within the Lotus community. Insertion mutagenesis with T-DNA,
transposable elements and retrotransposons have all been used in Lotus japonicus and an
EMS mutagenesis machine for reverse genetics has been established at the John Innes
Centre. To enable map-based cloning genetic maps are constructed and different methods
for positional cloning of symbiotic loci are currently applied in order to clone genes involved
in nodule initiation, nodule function as well as autoregulation (Tirichine et al., 2006). At the
Kazusa DNA Research Institute the genome of the model Lotus japonicus is under
sequencing and the complete sequence of substantial parts of the genome is already available
in public databases. The sequencing program is focused on gene rich regions and an
approach using seed points anchoring sequences onto the genetic map has been developed.
Taking advantage of the available genome and EST sequences a proteomic program has
been initiated on seed proteins and a transcriptome analysis based on Affymetix will soon be
available. A summary of the structural and functional genomics within the Lotus community
and the future perspectives will be given together with a discussion of the possibilities for
transfer of information into cultivated legumes (Fredslund et al., 2006).
References
TIRICHINE L., IMAIZUMI-ANRAKU H., YOSHIDA S., MURAKAMI Y., MADSEN L.H., MIWA
H., NAKAGAWA T., SANDAL N., ALBREKTSEN A., KAWAGUCHI M., DOWNIE A., SATO
S., TABATA S., KOUCHI H., PARNISKE M., KAWASAKI S. and STOUGAARD J. 2006.
Deregulation of a Ca2+/calmodulin-dependent kinase leads to spontaneous nodule
development. Nature, 441, 1153-1156.
Lotus genomics 55
FREDSLUND J., MADSEN L.H., HOUGAARD B.K., NIELSEN A.M, BERTIOLI D., SANDAL N.,
STOUGAARD J. and SCHAUSER L. 2006. A general strategy for the development of
anchor markers for comparative genomics in plants. BMC Genomics, 2006, 7, 207.
Lotus Newsletter (2007) Volume 37 (2), 56.
Animal production in Uruguay is limited by the productivity and quality of natural pastures
that represent more than 70% of the grazing area. Temperate forage legumes have been
adopted since the 60, particularly in intensive systems with cereal - perennial pastures
rotations. Forage legumes are important in the sustainability of agricultural systems and
natural ecosystems, with increments of up to 8 folds in the organic matter of agricultural
rotations compared with monoculture systems. However, the low proportion of cultivated
pastures reflects the difficulties in the establishment and persistence of introduced legumes.
The main cultivated legumes in rotation with cereals are Lotus corniculatus (LC), Trifolium
repens (TR) and T. pratense (TP), while L. subbiflorus (LS) and more recently L. uliginosus
(LU) are sown in natural pastures. The wide utilization of LC, LS, LU, is due to their
adaptation to soils with low P availability and the presence of tannins that diminish bloat
occurrence in cattle. The production of perennial legumes is limited by several
environmental restrictions (drought and flooding, acid soils, diseases and pests), even in the
adapted species. An additional restriction in Uruguay is the incompatibility of rhizobia
strains between species of the same genus. Strains of LC are parasitic in LS and LU; similar
incompatibility takes place with the introduction of TR or TP in areas with T. polymorphum,
a perennial native species. Plant breeding (PB) during the last decade has concentrated on
Lotus and Trifolium whose distribution varies with soil and climatic conditions. The
collection of landvarieties increases the possibility to generate differences due to natural
selection, through the adaptation to specific edaphic and climatic conditions. The strategy to
evaluate those differences is centered in the use of biochemical, physiologic and genetic
markers. Naturalized populations have been used in the past in PB (LC cv INIA Draco, a
cultivar more persistent and tolerant to short periods of drought in the summer). Farmers’
participation in collection and characterization of LC and TP assures a quick adoption of the
generated products (Project LESIS - FONTAGRO FTG 787/2005). The integration of a
multidisciplinary team carries out the research for water stress in the genus Lotus (Project
LOTASSA - FP6-2003-INCO-DEV2 PL-517617). Research advances in breeding of LC
and TP are described during the presentation.
56
Lotus Newsletter (2007) Volume 37 (2), 57 – 58.
Three Lotus species known as high value forage plants are present in Chile, L. corniculatus
(Lc), L. glaber (Lg) and L. uliginosus (Lu). There is no record of the date of their
introduction in the country but it would have happened in the first half of the twentieth
century. Today these species are naturalized in specific environments between 32° and 38° S
latitude. Lc is cultivated, but its spontaneous propagation is limited. Lg and Lu are broadly
distributed in mediterranean and southern humid climates, on neutral to moderately acidic
and acidic soils, respectively. One Lc cv. originated in Chile is available, Quimey. During
recent years the performance of 12 cvs., from north and south-America and Australia, has
been evaluated in Chile compared to Quimey (Acuña et al.,2002a). A naturalized germplasm
collection of Lg (11 accessions) and Lu (21 accessions) was characterized for agronomic
trait in different environments within the distribution area of each species is available
(Acuña et al., 2002b). The Lg accessions differ in plant hight, phytomass production and
N-fixation rate but show similar concentrations of condensed tannins (CT) in herbage (lower
than Lc and Lu). The Lu germplasm is in general of postrate growth habit contrasting with
the semierect New Zealand cv. Maku, but there are differences in plant hight among
accessions. They differ in fitomass production, N-fixation rate and CT concentration in most
of the environments. The Lg and Lu germplasm concentrate the herbage production in
spring more than Lc, but both species have accessions with an acceptable equilibrium
between the spring and summer production. These species are well adapted to soil with
limitations as texture, depth, acidity or Al toxicity and deficiencies of P, K, S and other
elements, as well as to water deficit caused by water shortage for irrigation or low rain
condition. When the Lg and Lc are the pasture´s (natural or sown) basic legumes, which
improves N plant nutrition and forage quality, they are mainly used in beef cattle production
systems. This occurs in rice crop areas where lotus use the land for two or three years in
rotation with the cereal, and in volcanic soil areas with irrigation water restrictions and in
sandy soil areas with water table near surface, all of them located in the Central –South zone
of the country (potential: 500.000 ha). In the humid zone of Southern Chile there are
extensive areas of acidic soils with high levels of Al saturation and P deficiencies where Lu
is broadly distributed and plays an important role in beef cattle production (potential:
1000.000 ha). On average, these kind of pastures produce 8 to 10 tons of DM per ha/year and
the live weight yield is around 350 to 500 kg per ha /year, depending on the zone and the
production phase – growing or finishing.
57
58 H. Acuña
References
ACUÑA P.H., FIGUEROA M., DE LA FUENTE A., ORTEGA F., y FUENTES C. 2002a.
Comportamiento de cvs. de Lotus corniculatus L. en diferentes ambientes de la VIII y
IX Regiones de Chile. [Performance of cvs of Lotus corniculatus L. in different
environments of the VIII and IX regions of Chile] Agro-Ciencia, 18(2), 75-84.
[Spanish]
ACUÑA P. H., FIGUEROA M., DE LA FUENTE A., ORTEGA, F., SEGUEL I. y MUNDACA R.
2002b. Caracterización agronómica de accesiones de Lotus glaber Mill. y Lotus
uliginosus Schkur. naturalizadas en Chile. [Agronomic characterization of accessions of
Lotus glaber Mill. and Lotus uliginosus Schkur. Naturalized in Chile] Agro-Ciencia,
18(2), 63-74. [Spanish]
Lotus Newsletter (2007) Volume 37 (2), 59 – 61.
The Brazilian subtropical region is limited northwise by the Tropic of Capricorn (24 o S) and
in the south by the extreme south of the state of RS, which borders Uruguay. Despite this
political limitation, the “Campos” area, in a broad sense, at the southern cone of South
America, encompasses an area of about 45million of ha with an enormous potential of
improvement and utilization. The natural pastures are still the most important forage
resource for animal production in the Brazilian subtropics. In the case of the state of RS, the
initial participation of the native pastures, that was of about 60% of all of the area, decreased
to about 10,5 million in 1995/96 and it is calculated today in less than 8 million of ha, in its
majority substituted by summer crops (soybeans, maize and rice), fruits (specially with
temperate species) and more recently by the aggressive advance of forestry (Pinnus,
Eucalyptus and Acacia). Despite all of this, this entire region could potentially be improved
by the introduction of temperate legumes due to its high forage value. The use of cultivated
temperate pastures of winter is also a good alternative to compose integrated crop-grazing
systems, since from the total area of approximately six million of ha cultivated with summer
crops in the state, only 12% are cultivated with wheat or other cultures in the winter, being
the rest rarely used (CONAB, 2007). This clearly indicates the great potential of use of
winter pastures that we have and that are not used, especially if legumes are incorporated to
the production systems. Despite its recognized importance, the use of legumes in practically
all the grazing systems is very limited. Although the legumes are extremely important
species in any system of utilization, its lack of persistence has been pointed as the biggest
limitation to its use and inadequate practices of management have been considerate as the
main cause of this failure at the level of the farmers. (Beuselinck et al., 1994). Rochon et
al.,(2004) consider that the benefits provided by the use of legumes partially are
counterbalanced, in tempered regions as well as in the Mediterranean regions, due to the
difficulties in the establishment, maintenance and management under grazing. Therefore, it
seems clear that, although the innumerable benefits of the use of legumes, its lack of
persistence has been an important factor that has limited the expansion of its use in different
regions. In global terms, recent data (Shelton et al., 2005) indicate that, in Brazil, only
around 2% of its 130 million of ha of cultivated tropical pastures possess some participation
of legumes. In the Southern of Brazil, even though reliable estimates are not available, the
picture is not very different. Therefore, it seems important that, at this moment, the causes of
the small use of legumes in grazing systems be studied and understood, and it is important as
well to have a re-study of the potential areas of use and the benefits from them. In this
context, one of the important temperate groups of forage species is the genus Lotus. The
genus Lotus possesses more than 170 species, presenting varied forms of growth, and cycles
59
60 M. Dall’Agnol and S.M.S. Basso
of life, distributed throughout different climatic regions. Amongst these species one of the
most important for the south region of Brazil is the Lotus corniculatus. Hopkins et al. (1996)
reported that the pastures formed with Lotus can play a significant role in situations in which
fertilizers and the management, necessary to support fertilized grasses with N or mixed with
white clover, cannot be justified by economic or environmental reasons. Despite all this
potential, Brazil possesses only one cultivar commercially available, a material that was
developed and released in the decade of 1960, lacking, therefore, a more modern
germoplasm, with superior characteristics. Compared with other tempered species, the
bidsfoot trefoil is a much less demanding species in soil fertility, demanding a lower amount
of inputs, although it requires more care about management related to frequency and
intensity of utilization. Moreover, it is a species very well adapted to most of our climatic
conditions, presenting an excellent natural reseeding and not causing bloating to the animals.
Despite these advantages, its use in production systems has been very limited and its lack of
persistence for long periods also has been observed, mainly due to problems of management
and the presence of diseases. Therefore, the possibilities of use of legumes with proven
forage potential and that require less amount of inputs should be stimulated and at the same
time we should try to understand the reasons for its low use. Moreover, some native species,
as for example, those that belong to the genus Trifolium, Adesmia, and Desmodium, whose
productive potential have been indicated many years ago, and that are also species with less
requirements in terms of soil fertility, must also be present in the evaluation programs and
breeding programs of all research institutions, at least in the public ones. Currently, due to
the pressure imposed by the expansion of crop areas, the areas of pastures have been
dislocated to marginal areas, in degraded soils with low fertility. As a consequence of this,
the pastures have been constantly defied in their adaptative capacity to the different
conditions of stress, as salinity, alkalinity, drought, acidity, amongst others, generating
frustrating results. Therefore, an alternative would be the use of species that already possess
some degree of tolerance to these stresses or even the improvement of species, aiming at the
adaptation in these stressful environments. Since many years, the traditional concept of,
adapting the environment to the plant, in accordance with its requirements has shown its
incapacity to deal with the problem, especially in developing countries. Therefore, a new
alternative is been seeked for many years, that is, to adapt the plant to the stressful
environment, always remembering that minimum levels of production are necessary to reach
sustainable levels of production. That is, some amount of inputs must be added, even to the
plants that are considered tolerant or adapted, otherwise, zero input, generally results in zero
output! (Sanchez and Salinas, 1981).
References
BEUSELINCK P.R. (Ed.) 1999. Trefoil: the science and technology of the Lotus. Madison,
CSSA, 267pp
BEUSELINCK P.R., BOUTON J.H., LAMP W.O., MATCHES A.G., MCCASLIN M.H., NELSON
C.J., RHODES L.H., SHEAFFER C.C., and VOLENEC J.J. 1994. Improving legume
persistence in forage crops systems. Journal of Production Agriculture, 7, 311-322.
Temperate forage legumes in Brazil 61
HOPKINS A., MARTYN T.M. JOHNSON R.H. SHELDRICK R.D. and LAVENDER R.H. 1996.
Forage production of two Lotus species as influenced by companion grass species.
Grass and Forage Science, 51, 343-349.
ROCHON J.J., DOYLE C.J., GREEF J.M., HOPKINS A., MOLEE G., SITZIA M., SCHOLEFILED
D., and SMITH C.J. 2004. Grazing legumes in Europe: a review of their status,
management, benefits, research needs and future prospects. Grass and Forage Science,
59, 197-214.
SANCHEZ J.G. and SALINAS P.A. 1981. Low-input technology for managing oxisoils and
ultisoils in tropical America. Advances in Agronomy, 34, 279-406
62
Dunes restoration at Valencia 63
value in the windward sector and crest of the primary dune. Cover by L. creticus gradually
decreased when approaching to the fixed dunes, being minimum or null in the woody plant
communities. On the other hand, the “malladas” are another type of ecosystem present in the
Devesa, which are located in the depressions between dunes. Soils in the “malladas” are
muddy, with variable salinity levels and become flooded as a consequence of rain. In zones
of medium salinity that conserve certain degree of humidity throughout the year, the vegetal
alliances developed are Juncion maritimi Br.-Bl. 1931 and Plantaginion crassifoliae Br.-Bl.
1931, to both of which a Lotus species was associated. This species was described in the
literature to be Lotus corniculatus crassifolius (2n=24) (Grant, 1995). However,
chromosomal counts performed in our laboratory found it to have 2n=12. The location of
populations of this species within the Devesa was determined and the conductivity of soils in
which they are developed was analyzed and found to be very variable (0.2 to 13.0 ds/m).
Finally the biodiversity study was completed by taking samples of L. creticus plants for the
analysis of root colonization by mycorrhyzal fungi and the isolation of rhizobia from root
nodules of both Lotus species, which are currently being characterized.
References
BENAVENT OLMOS J.M., COLLADO ROSIQUE P., MARTÍ CRESPO R.M., MUÑOZ
CABALLER A., QUINTANA TRENOR A., SÁNCHEZ CODOÑER A y VIZCAINO
MATARREDONA A. 2004. La restauración de las dunas litorales de la Devesa de
l`Albufera de Valencia. Ajuntament de Valencia. 65 p. [http://www.albufera.com].
FAO-UNESCO. 1988. Soil Map of the World. Revised Legend FAO. Roma.
GRANT W.F. 1995. A chromosome atlas and interspecific-intergeneric index for Lotus and
Tetragonolobus (Fabaceae). Canadian Journal of Botany 73, 1787-1809.
RUBIO DELGADO J.L., ANDREU PÉREZ V. y SANCHIS DUATO E. 1998. Los suelos de la
Devesa de la Albufera. [The soils of Devesa de la Albufera]. Revista Valenciana
d´Estudis Autonòmics, 22, 129-144. [Spanish]
Lotus Newsletter (2007) Volume 37 (2), 64.
The Mediterranean basin is one of the hot-spots of diversification of Lotus. Recent studies
using nuclear ribosomal markers have clarified generic delimitations and phylogenetic
relationships with the related Tetragonolobus and Dorycnium. However, documented
patterns of intraspecific variation concerning karyological and molecular markers are
scanty. In this talk we provide molecular evidence documenting patterns of reticulate
hybridization in sympatric populations of Lotus from the Balearic Islands (Lotus dorycnium
and Lotus fulgurans). Nuclear markers from ribosomal ITS sequences suggest asymmetric
gene flow between widespread, non-endangered species and endemic species. Contrary to
expectations, asymmetric pollen flow is from the rare species to the widespread one. Patterns
of chloroplast and nuclear variation at pseudogenized loci suggest the presence of a clear
phylogeographic scenario in these continental islands.
64
Lotus Newsletter (2007) Volume 37 (2), 65 – 66.
The genus Lotus in the Canary Islands is represented by 24 species, being seventeen of them
endemic (Acebes et al., 2004). According to other authors (Sandral et al., 2006) the number
is lesser (14 species and some infraspecific taxa). They are included in several sections o
subgenera depending on the taxonomic view of diverse authors. The Canary endemic Lotus,
including L. glaucus and L. lancerottensis which are also present in Madeira, are included in
two taxa: Sect. Pedrosia (Lowe) Christ or subgen. Pedrosia (Lowe) Brand and subgen.
Rhyncholotus Monod or sect. Rhyncholotus (Monod) Sokoloff. The non endemic species are
included in some infrageneric taxa. Regarding to the taxonomic treatment of sect. Pedrosia
the publication of Sandral et al. (2006) has produced several taxonomical changes. The main
changes are: L. glaucus is considered endemic to Madeira and Salvagen Islands, and
consequently not represented in Canary Islands (although they mention a record for L.
glaucus s.l. to Fuerteventura, as a possible synonym of L. erythrorhizus Bolle). The records
of L. glaucus mentioned for Canaries are now considered to belong to L. tenellus (Lowe)
Sandral, Santos & Sokoloff. Major changes are made in the group of the typical Lotus of the
Canary pine woodland: L. holosericeus Webb & Berthel. is included as synonym of L.
spartioides Webb & Berthel, an endemic taxon of the Gran Canaria pine woodland. L.
hillebrandii Christ, endemic of La Palma, is included as a subspecies of L. campylocladus
Webb & Berthel., and the type subspecies remain as endemic of Tenerife. Currently Felicia
Oliva Tejera is carrying out the studies of her PhD in our Department at the University of La
Laguna in collaboration with the Botanical Garden “Viera y Clavijo” of Las Palmas de Gran
Canaria which is entitled “Morphological and molecular studies of the endemic Canary
Lotus (Fabaceae: Loteae) of the pine woodland”. The first results of the mollecular
(isoenzymes) and morphological studies (Oliva Tejera, 2006) indicate that L. holosericeus,
an endemic of the south pine woodland of Gran Canaria, is different to L. spartioides, an
endemic of the north and northwest pine woodland of that island. The infraspecific status of
L. hillebrandii is also considered. We do not know other different use that ornamental for the
Canary Lotus although could be used as a fodder. Mainly Lotus section Rhyncholotus,
commonly called “picos de paloma” are used for such purpose. We think they could play a
role in the soil conservation in arid, semiarid and dry areas, ranging from pine woodland to
the coast in the Canary Islands.
65
66 J.R. Acebes Ginoves and F. Oliva Tejera
References
ACEBES GINOVÉS J.R., ARCO AGUILAR M. DEL, GARCÍA GALLO A., LEÓN ARENCIBIA
M.C., PÉREZ DE PAZ P.L., RODRÍGUEZ DELGADO O., WILDPRET DE LA TORRE W.,
MARTÍN OSORIO V.E., MARRERO GÓMEZ M.C. and RODRÍGUEZ NAVARRO M.L..
2004. División Spermatophyta. In IZQUIERDO I., MARTÍN J.L, ZURITA N. and
ARECHAVALETA M. (eds.) Lista de especies silvestres de Canarias (hongos, plantas y
animales terrestres) 2004. Consejería de Política Territorial y Medio Ambiente.
Gobierno de Canarias. p: 99-140.
SANDRAL G., REMIZOWA M.V. and SOKOLOFF D. 2006. A taxonomic survet of Lotus
section Pedrosia (Leguminosae, Loteae). Wulfenia 13: 97-102.
Lotus Newsletter (2007) Volume 37 (2), 67 - 68.
ROLANDO J.C. LEÓN*, GUSTAVO STRIKER, PEDRO INSAUSTI and SUSANA B. PERELMAN
IFEVA – CONICET, Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín
4453, CP1417DSQ Buenos Aires, Argentina.
*
Corresponding author click here for Spanish version
Temperate subhumid grasslands, in the eastern part of South America, cover the vast plains
of central-eastern Argentina, Uruguay and southern Brazil. This grassland region can be
divided into two subregions: (1) the pampas, in Argentine and (2) the campos of Uruguay
and Southern Rio Grande do Sul (Brazil) (Soriano, 1991). In the Pampas, some of the areas
have seldom or never been cultivated. Grazing has been the only modifying agent in these
areas, which are mostly in low-lying locations of the flooding Pampa, the western portion of
the Pampa (Soriano, 1991). In the flooding Pampa, the natural grasslands and pastures
constitute the basis of cattle breeding. These grasslands show a great floristic heterogeneity
in which herbaceous plant communities are arranged forming intricate landscape mosaics
(Burkart et al., 1990). Four major grasslands habitat types have been defined: mesophyte
prairies (MP), humid prairies (HP), meadows (M) and halophyte steppes (HS) (Ghersa et al.,
2007). In comparison to other grasslands in the world, these ones show a great proportion of
exotic species: 10% within perennial grasses, 16% within annual grasses, 19% within
perennial dicots and 55% within annual dicots. Native legumes in these communities are
very scarce (7 species), the exotic ones are more numerous (14 species) and they are more
significant in produced biomass (Ghersa et al., 2007). The species of the Lotus genus are of
the most recent introduction. In the north of the region, in 1968, Lotus tenuis (Lotus glaber
Mill.) showed different constancy values in each one of the communities: MP=8.6,
HP=11%, M=8%, HS=1%. In recent evaluations carried out in 51 sites of two of such
communities, considerable increases were registered in the presence of L. tenuis: from 4 to
99% in MP and from 4 to 50% in HS (Ghersa et al., 2007). In the south of the region the
presence of this legume was already important 30 years ago: MP=8.5%, HP=34%, M=24%
and HS=7% (Ghersa et al., 2007). The wide distribution of Lotus tenuis in the humid prairies
and meadows is considered of great relevance for forage production. The reason behind such
distribution is the high tolerance of L. tenuis to long-term flooding, one of the major
disturbances affecting these plant communities. In experiments carried out in these
communities we have advanced in the identification of anatomical, morphological and
physiological attributes conferring to L. tenuis tolerance to the lack of oxygen due to the
flood (Striker et al., 2005). In this sense, we have found that the flooded plants of L. tenuis
increase the porosity notably in the stems (porosity 13%) and roots (porosity 28%), they
locate a high proportion of their leaves above the water level (53%) and they can maintain
unaffected their stomatal conductance and photosynthesis for more than three weeks (Striker
et al., 2005). These responses tend to facilitate the capture and transport of oxygen to roots
and maintain carbon fixation and biomass production under flooding conditions. Besides,
68 R.J.C. León, G. Striker, P. Insausti and S.B. Perelman
we have studied the interaction between flooding and trampling, an unavoidable sequel of
cattle grazing (Striker et al., 2006). In this sense, we found that the roots of L. tenuis possess
a low mechanical resistance (250 KPa) with relationship to the pressure that can generate on
them the hoof of a cow (>300 KPa) (Striker et al., 2006), in consequence their plants are
much damaged when both disturbances are combined. This aspect should be taken into
account for grassland management.
References
BURKART S.E., LEÓN R.J.C. and MOVIA C.P. 1990. Inventario fitosociológico del pastizal
de la Depresión del Salado (Prov. de Bs. As.) en un área representativa de sus
principales ambientes. Darviniana, 30, 27–69.
GHERSA C.M, PERELMAN S.B., BURKART S.E. and LEON R.J.C. 2007. Floristic and
structural changes related to opportunistic soil tilling and pasture planting in grassland
communities of the Flooding Pampa. Biodiversity and Conservation, 16, 1575-1592.
SORIANO A. 1992. Río de la Plata Grasslands. Ecosystems of the world 8A. COUPLAND R.T.
(ed.) Natural grasslands. Introduction and Western Hemisphere. Elsevier, Amsterdam.
pp. 367–407.
STRIKER G.G., INSAUSTI P., GRIMOLDI A.A., PLOSCHUK E.L. and VASELLATI V. 2005.
Physiological and anatomical basis of differential tolerance to soil flooding of Lotus
corniculatus L. and Lotus glaber Mill. Plant and Soil, 276, 301-311.
STRIKER G.G., INSAUSTI P., GRIMOLDI A.A. and LEON R.J.C. 2006. Root strength and
trampling tolerance in the grass Paspalum dilatatum and the dicot Lotus glaber in
flooded soil. Functional Ecology, 20, 4–10.
Lotus Newsletter (2007) Volume 37 (2), 69 – 70.
1
ICBiBE. Botanic Garden, University of Valencia, Quart 80, 46008 Valencia, SPAIN
2
Dept. of Systems Eng. & Control, Technical University of Valencia, Camí de Vera 14,
46022 Valencia, SPAIN
*
Corresponding author click here for Spanish version
The flora at the coastal dunes ecosystems in the Valencian Community has a great biological
interest. These ecosystems are suffering in the last decades a strong harassment and urban
pressure, leading to their massive and continuous destruction. Therefore, all studies towards
the knowledge of the vegetal species living in these dunes, and their conservation, are of
great interest (Harris and Davy, 1986; Jusaitis et al., 2004; Carter and Ungar, 2004). The
dunes cords are important, for they receive the direct impact of wind protecting the
ecosystems placed behind. Dunes plants are specialized as a function of their proximity to
the seacoast. Factors most influencing this specialization are the soil mobility, salinity
(Katembe et al., 1998; Gulzar and Khan, 2001; Debez et al., 2004), abrasive effect of wind
and low retention of water in sandy soils (Khan and Ungar, 1984; Khan et al., 2000; Zia et
al., 2004). The distribution of the species in the different areas of the dunes results from their
physiological requirements and their interaction with other species (Costa et al., 1982).
Thus, Lotus creticus belongs to the association Medicagini mariane-Ammophiletum
australis, found in the embryonic dunes and in those in movement. The aim of the study
performed was to find the values of temperature and salinity leading to optimal germination.
To this end, scarified seeds were germinated in Petri dishes during one month. A wide set of
temperature and salinity conditions were applied. The percentage of germinated seeds is
close to 100% in all the conditions studied, with very low variance, with the exception of the
extreme conditions corresponding to the alternating temperatures 40º/20ºC, and the low
constant temperature 10ºC. The same trend is observed in the velocity of germination. With
the exception of the extreme conditions mentioned, there is a high correlation between the
percentage of germination and its velocity. Though Medicago marina is the representative
plant in the association Medicagini mariane-Ammophiletum australis, Ammophila arenaria
the dominant, and Lotus creticus an accompanying one, it turns out that it presents higher
velocities of germination than M. marina in a wider range of conditions. Thus, for instance,
Lotus creticus covers the void left by M. marina in extreme conditions. Concerning
tolerance to different salt concentrations, a high percentage and velocity of germination is
observed at 100mM. At 200 mM the percentage of germination remains high, yet the
velocity of germination decreases notably. At higher salt concentrations both percentage and
velocity of germination are very low. More details about the experimental conditions,
indices used, and results obtained will be presented complementary.
69
70 C.López Valiente, E. Estrellés, P. Soriano and J. Picó
References
CARTER C.T and UNGAR I.A. 2004. Relationship between seed germinability of Spergularia
marina (Caryophyllaceae) and formation of zonal communities in an inland salt marsh.
Annals of Botany. 93, 119-125.
DEBEZ A., HAMED K.B., GRIGNON C. and ABDELLY C. 2004. Salinity effects on
germination, growth, and seed production of the halophyte Cakile maritime. Plant and
soil, 262, 179-189.
GULZAR S. and KHAN M.A. 2001. Seed germination of a halophytic grass Aeluropus
lagopoides. Annals of Botany, 87, 319-324.
HARRIS D. and DAVY A.J. 1986. Regenerative potential of Elymus farctus from rhizome
fragments and seed. Journal of Ecology, 74, 1057-1067.
JUSAITIS M., POLOMKA L., SORENSEN B. 2004. Habitat specificity, seed germination and
experimental translocation of the endangered herb Brachycome muelleri (Asteraceae).
Biological Conservation, 116, 251-266.
KATEMBE W.J., UNGAR I.A. and MITCHELL J.P. 1998. Effect of salinity on germination
and seedling growth of two Atriplex species (Chenopodiaceae). Annals of Botany, 82,
167-175.
KHAN M.A. and UNGAR I.A. 1984. The effect of salinity and temperature on the
germination of polymorphic seeds and growth of Atriplex triangularis Willd. American
Journal of Botany, 71, 481-489.
KHAN M.A., GUL B. and WEBER D.J. 2000. Germination responses of Salicornia rubra to
temperature and salinity. Journal of Arid Environments, 45, 207-214.
ZIA S. and KHAN M.A. 2004. Effect of light, salinity, and temperature on seed germination
of Limonium stocksii. Canadian Journal of Botany, 82, 151-157.
Lotus Newsletter (2007) Volume 37 (2), 71 – 73.
In our laboratories we carry out research on nitrogen assimilation in Lotus plants and the
possible relationships with drought stress situations that become a likely cause of the loss of
these forage plants when they are cultivated (Díaz et al., a, b). Some of our research has been
conducted with the model legume Lotus japonicus, while other research was done on
cultivated species. Lotus japonicus plants are able to use both nitrate and ammonium as
inorganic nitrogen sources for ulterior assimilation, or, alternatively, they can also use
atmospheric dinitrogen through Mesorhizobium loti symbiosis. Primary nitrate assimilation
takes place predominantly in the roots of the plant, being strongly dependent on the age and
limitation of space for root growth (Orea et al., 2001; Pajuelo et al., 2002). Attempts of
genetic manipulation of root-shoot partitioning of nitrate assimilation, either by increasing
external nitrogen availability (Orea et al., 2005a), or using a transgenic approach (Orea et
al., 2005b), were not able to shift this partitioning to the aerial part of the plant, thus
suggesting the existence of ecophysiological adaptations for a preferential use of external
nitrogen in the root (Márquez et al., 2005). This situation makes crucially important the
mobilization of nitrogen from roots to shoots of the plant, particularly with regard to
asparagine metabolism. On the other hand, in our laboratory we have also recently shown
the importance for this plant of other forms of secondary nitrogen assimilation such as
reassimilation of ammonium released by photorespiration. We have used a mutagenesis
approach to demonstrate the essentiality of plastidic glutamine synthetase in this process.
However, this was not the case for primary ammonium assimilation, a process which can
rely basically on cytosolic glutamine synthetase (Orea et al., 2002; Betti et al; 2006). There
is also some influence of photorespiration on the level of different ammonium transporters
(D'Apuzzo et al., 2004). Nitrogen metabolism in Lotus plants shows also a strong connection
with drought stress situations, mainly through the biosynthesis of proline, which becomes a
very nice marker of osmotic stress situations in this plant (Díaz et al., 2005 b,c). Proline
metabolism is greatly influenced by the type of nitrogen nutrition provided to the plant (Díaz
et al., 2005c). At present we are also investigating the possible interconnection between
photorespiration and drought stress situations in these plants.
71
72 A.J. Márquez, M. Betti, M. García-Calderón, A. Credali, P. Díaz and J. Monza
References
BETTI M., ARCONDEGUY T. and MÁRQUEZ A.J. 2006. Molecular analysis of two mutants
from Lotus japonicus deficient in plastidic glutamine synthetase: functional properties of
purified GLN2 enzymes. Planta, 224, 1068-1079.
D'APUZZO E., ROGATO A., SIMON U., ALAOUI H.E., BARBULOVA A., BETTI M., DIMOS
M., KATINAKIS P., MARQUEZ A.J., MARINI A., UDVARDI M.K. and CHIURAZZI M.
2004. Characterisation of three functional high affinity ammonium transporters in Lotus
japonicus with differential transcriptional regulation and spatial expression Plant
Physiology, 134, 1763-1774.
DIAZ P., BORSANI O. and MONZA J .2005a. Lotus-related species and their agronomic
importance. In MÁRQUEZ A.J. (Ed.) Lotus japonicus Handbook. Springer, The
Netherlands, pp. 25-37.
DIAZ P., MONZA J. and MÁRQUEZ A.J. 2005b. Drought and saline stress in Lotus japonicus
In MÁRQUEZ A.J. (Ed.) Lotus japonicus Handbook. Springer, The Netherlands, pp.
39-50.
DIAZ P., BORSANI O., MÁRQUEZ A.J. and MONZA J . 2005c. Osmotically induced proline
accumulation in Lotus corniculatus leaves is affected by light and nitrogen source. Plant
Growth Regulation, 46, 223-232.
MÁRQUEZ A.J., BETTI M., GARCÍA-CALDERÓN M., PALOVE-BALANG P., DIAZ P. and
MONZA J. 2005. Nitrate assimilation in Lotus japonicus. Journal of Experimental
Botany, 56, 1741-1749.
OREA A., PAJUELO P., PAJUELO E., MÁRQUEZ A.J. and ROMERO J.M. 2001.
Characterisation and expression studies of a root cDNA encoding for ferredoxin-nitrite
reductase from Lotus japonicus. Physiologia Plantarum, 113, 193-202.
OREA A., PAJUELO P., PAJUELO E., QUIDIELLO C., ROMERO J.M. and MÁRQUEZ A.J. 2002.
Isolation of photorespiratory mutants from Lotus japonicus deficient in glutamine
synthetase Physiologia Plantarum, 115, 352-361.
OREA A., PROSSER I., ROMERO J.M. and MÁRQUEZ A.J. 2005a. Transgenic plants affected
in nitrate assimilation. In MÁRQUEZ A.J. (Ed.) Lotus japonicus Handbook. Springer,
The Netherlands, pp. 329-340.
OREA A., PAJUELO P., ROMERO J.M. and MÁRQUEZ A.J. 2005b. Nitrate assimilation:
influence of nitrogen supply In MÁRQUEZ A.J. (Ed) Lotus japonicus Handbook.
Springer, The Netherlands, pp. 329-340.
Nitrogen assimilation in Lotus and drought stress 73
PAJUELO P., PAJUELO E., OREA A., ROMERO J.M. and MÁRQUEZ A.J. 2002. Influence of
plant age and growth conditions on nitrate assimilation in roots of Lotus japonicus
plants. Functional Plant Biology, 29, 485-494.
Lotus Newsletter (2007) Volume 37 (2), 74 - 75.
1
Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús
(IIB-INTECh) Camino de Circunvalación de La Laguna Km 5. Casilla de Correo 164
(B7130IWA) Chascomús. Provincia de Buenos Aires. Argentina.
2
Instituto Nacional de Tecnología Agropecuaria Estación Experimental Agropecuaria
Pergamino, CC 31, (2700), Pergamino, Provincia de Buenos Aires, Argentina
*
Corresponding author click here for Spanish version
74
Lotus tenuis under saline stress 75
References
CHIESA, M.A., RUIZ, O.A. and SÁNCHEZ, D.H. 2004. Lotus hairy roots expressing inducible
arginine decarboxylase activity. Biotechnology Letters, 26, 729-733.
CUEVAS J.C., SÁNCHEZ D.H., MARINA M. and RUIZ O.A. 2004. Do polyamines modulate
the Lotus glaber NADPH oxidation activity induced by the herbicide methylviologen?.
Functional Plant Biology (ex-Australian Journal of Plant Physiology), 31, 921-928.
ECHEVERRÍA M., MARINA M., MENÉNDEZ A., MONTES M., RUIZ O.A., SANNAZZARO A.,
SCAMBATO A. and SOSA M. 2006. Plant polyamine metabolism and arbuscular
mycorrhizal colonization. 5th International Conference on Mycorrhiza, Granada,
España. 23-27 July 2006.
ESTRELLA M.J., CASTAGNO L.N., MUÑOZ S., CASSAN F., RUIZ O.A., OLIVARES J., SOTO
M.J. and SANJUÁN J. 2007. Evaluación taxonómica, simbiótica y fisiológica de
simbiontes de L. tenuis para la formulación de inoculantes de alta calidad en la región de
la Pampa Deprimida del Salado. Reunión Latinoamericana de Rizobiología – RELAR
2007. Los Cocos, Córdoba, Argentina. 25 – 28 Marzo 2007.
SÁNCHEZ D.H., CUEVAS J.C., CHIESA M.A. and RUIZ O.A. 2005. Free spermidine and
spermine content in Lotus glaber under long-term salt stress. Plant Science, 2, 541-546.
SANNAZZARO A., ECHEVERRÍA M., EDGARDO A., RUIZ O.A, and MENÉNDEZ A. 2007.
Modulation of polyamine balance in Lotus glaber by salinity and arbuscular
mycorrhiza. Plant Physiology and Biochemistry, 45, 39-46.
SANNAZZARO A., RUIZ O. A., ALBERTÓ E. and MENÉNDEZ A. 2004. Presence of different
arbuscular mycorrhizal infection patterns in Lotus glaber growing in the Salado River
Basin. Mycorrhiza, 14, 139-142.
SANNAZZARO A., RUIZ O.A, ALBERTÓ E. and MENÉNDEZ A. 2006. Lotus glaber salt stress
alleviation by Glomus intraradices. Plant and Soil, 285, 279-287.
Lotus Newsletter (2007) Volume 37 (2), 76 – 77.
The economic importance of legumes is related with their capacity to fix atmospheric
nitrogen, thereby reducing agricultural cost through a reduction of fertilizer inputs and
decreasing environmental contamination. The process of biological nitrogen fixation is
present in many ecosystems and it is efficiency is determined by the environmental
conditions. Saline stress is one of the main factors limiting legume productivity in arid and
semi-arid regions affected by water or soil salinity, particularly when plant growth depends
on symbiotic nitrogen fixation, since high salt concentrations in soil is also a negative factor
for growth and activity of soil bacteria that establish symbiosis with legumes, collectively
called rizobia (Asraf and Harris, 2004). The area of land affected by secondary salinity
(salinity caused by human activity) is steadily increasing, with recent worldwide estimates
that over 70 million ha of agricultural land is affected (FAO, 2005). Salinity impact on plants
in two main ways: osmotic stress and ion toxicity (Munns, 2005). Osmotic stress is caused
by ions (mainly Na+ and Cl-) in the soil solution decreasing the availability of water to roots.
Ion toxicity occur when plant roots take up Na+ and/or Cl- and these ions accumulated to
detrimental levels in leaves. Ion imbalances and nutrient deficiency, particularly for K+
nutrition, can be also occur (Tejera et al., 2006). The accumulation of compatible solutes in
considered an adaptative response and therefore, molecular indicators of tolerance to salt
stress and solutes should be studied within the highly specialized structures of legumes, the
root nodules. The capacity of nodules to maintain a significant level of nitrogen fixation
under salt conditions is determined by the energetic processes (nodule and bacteroid
responses) and metabolic processes that lead to the export and import of photosynthesized
and by the senescent processes. At the cellular level, the information on nodule and
bacteroid metabolites, the enzymes involved in carbohydrate metabolism and enzymes
required for assimilation of fixed nitrogen are essential to understand the consequences of
saline stress on nodule functioning and therefore on the symbiosis. Salinity induces changes
in the plant hormonal balance not only by the accumulation of ABA but also inducing a
reduction of the levels of growth-activating hormones such as auxins and cytokinins.
Ethylene and other growth regulators like salicylic acid play an important role in the
response to salt stress (Glyan´ko et al., 2005) due to its ability to induce a protective effect on
plant under stress. In addition, it has been reported the efficiency of pre-treatments with
different phytohormones for restoration of metabolic alterations induced in some legumes
by NaCl, such as Vicia faba, Vigna and Phaseolus vulgaris (Khadri et al., 2006). Recent
research on high salinity responses in Medicago truncatula and Lotus japonicus implied that
76
77
a large proportion of the genome is involved in high-salinity stress responses (Udvardi et al.,
2007). Genome-wide identification of genes regulated by drought of high salinity conditions
has manifold significance.
References
ASRAF M. and HARRIS P. J.C. 2004. Potential indicators of salinity tolerance in plants. Plant
Sciences, 166, 3-16.
FAO 2005. Global network on integrated soil management for sustainable use of
salt-affected soils. FAO Land and Plant Nutrition Management Services, Rome Italy.
http://www.fao.org/ag/agl/agll/spush.
GLYAN´KO A.K., MAKAROVA L.E., VASILÉVA G.G. and MORONOVA N.V. 2005. Possible
involvement of hydrogen peroxide and salicylic acid in the legume –Rhizobium
symbiosis. Biology Bolletin, 32, 245-249
KHADRI M., TEJERA N.A. and LLUCH C. 2006. Alleviation of salt stress in common bean
(Phaseolus vulgaris) by exogenous abscisic acid supply. Journal of Plant Growth
Regulation, 25, 110-119.
MUNNS R. 2005. Genes and salt tolerance: bringing them together. New Phytologist, 167,
645-663.
TEJERA N.A., SOUSSI M. and LLUCH C. 2006. Physiological and nutritional indicators of
tolerance to salinity in chickpea plants growing under symbiotic conditions.
Environmental and Experimental Botany, 58, 17-24.
UDVARDI M.K., KAKAR K., WANDREY M., MONTANARI O., MURRAY J., ANDRIANKAJA
A., ZHANG JI-YI., BENEDITO V., HOFER J.M.I., CHUENG F. and TOWN C.D. 2007.
Legume Transcription Factors: Global Regulators of Plant Development and Response to
the Environment. Plant Physiology, 144, 538-549.
Lotus Newsletter (2007) Volume 37 (2), 78 – 80.
The effect of drought on nitrogen fixation (NF) has been widely reported (see Zahran, 1999).
Among the factors, such as oxygen limitation and nitrogen feedback, a shortage in nodule
carbon flux has also been related to the inhibition of NF under drought (Arrese-Igor et al.,
1999). In these conditions, nodule sucrose synthase (SS) activity sharply declines (González
et al., 1995), thus limiting the carbon flux required for bacteroid respiration. Indeed sucrose
accumulation and malate depletion take place in nodules as a result of SS down-regulation
(González et al., 1998; Gálvez et al., 2005). Recently, by using a split root system in pea
plants, it has been shown that the cause of NF inhibition under drought is of a local origin,
rather than relying on a systemic signal (Marino et al., 2007). Key parameters of carbon
metabolism showed also a local regulation, correlated to NF inhibition, although nitrogen
feedback regulation needs to be further explored in this split root system. Both factors seem
to be crucial for the regulation of NF under drought (Ladrera et al, 2007). However, carbon
metabolism has been shown to play not such a main but a secondary role in plants of the
genus Medicago. Naya et al. (2007) concluded that a decrease in SS expression and activity,
although relevant, was not the cause of the drought-induced loss of nitrogenase activity in
alfalfa. Interestingly, a similar response has been found in the model legume Medicago
truncatula (R. Ladrera, E.M. González, and C. Arrese-Igor, unpublished data). A recent
proteome analysis (Larrainzar et al., 2007) of plant and bacteroid fractions of Medicago
truncatula root nodules under drought stress reveals that both plant and bacteroid fractions
respond simultaneously to water-deficit at the protein level. It can be inferred from the
proteomic analysis that the plant response in nodules involves a global reduction of plant
protein biosynthesis and a down-shift of cellular carbon and nitrogen metabolism and also
sulfur metabolism, thus reducing the energy-demanding process of NF. Drought response of
nodule metabolism in Lotus japonicus has not been extensively approached by now.
However, several evidences suggest that alkaline invertase could play a relevant role in
nodule carbon metabolism (Horst et al., 2007; Flemetakis et al., 2006), diminishing the
exclusive role of SS, as carbon supplier of nodule metabolism in the model legume Lotus
japonicus.
References
ARRESE-IGOR C., GONZÁLEZ E.M., GORDON A.J., MINCHIN F.R., GÁLVEZ L., ROYUELA
M., CABRERIZO P.M. and APARICIO-TEJO P.M. 1999. Sucrose synthase and nodule
78
Carbon metabolism and water stress 79
nitrogen fixation under drought and other environmental stresses. Symbiosis, 27,
189-212.
FLEMETAKIS E., EFROSE R.C., OTT T., STEDEL C., AIVALAKIS G., UDVARDI M.K. and
KATINAKIS P. 2006. Spatial and temporal organization of sucrose metabolism in Lotus
japonicus nitrogen-fixing nodules suggests a role for the elusive alkaline/neutral
invertase. Plant Molecular Biology, 62, 53-69.
GÁLVEZ L., GONZÁLEZ E.M. and ARRESE-IGOR C. 2005. Evidence for carbon flux shortage
and strong carbon/nitrogen interactions in pea nodules at early stages of water stress.
Journal of Experimental Botany, 56, 2551-2561.
GONZÁLEZ E.M., GORDON A.J., JAMES C.L. and ARRESE-IGOR C. 1995. The role of
sucrose synthase in the response of soybean nodules to drought. Journal of
Experimental Botany, 46, 1515-1523.
GONZÁLEZ E.M., APARICIO-TEJO P.M., GORDON A.J., MINCHIN F.R., ROYUELA M. and
ARRESE-IGOR C. 1998. Water-deficit effects on carbon and nitrogen metabolism of pea
nodules. Journal of Experimental Botany, 49, 1705-1714.
HORST I., WELHAM T., KELLY S., KANEKO T., SATO S., TABATA S.. PARNISKE M. and
WANG T.L. 2007. TILLING mutants of Lotus japonicus reveal that nitrogen
assimilation and fixation can occur in the absence of nodule-enhanced sucrose synthase.
Plant Physiology, 144, 806–820.
LADRERA R., MARINO D., LARRAINZAR E., GONZÁLEZ E.M. and ARRESE-IGOR C. 2007.
Reduced carbon availability to bacteroids and elevated ureides in nodules, but not
shoots, are involved in the nitrogen fixation response to early drought in soybean. Plant
Physiology, (Under review, provisionally accepted)
LARRAINZAR E., WIENKOOP S., WECKWERTH W., LADRERA R., ARRESE-IGOR C. and
GONZALEZ E.M. 2007. Medicago truncatula Root Nodule Proteome Analysis Reveals
Differential Plant and Bacteroid Responses to Drought Stress. Plant Physiology, 144,
1495–1507.
MARINO D., FRENDO P., LADRERA R., ZABALZA A., PUPPO A., ARRESE-IGOR C. and
GONZÁLEZ E.M. 2007 Nitrogen fixation control under drought stress: localized or
systemic? Plant Physiology, 143, 1968-1974.
NAYA L., LADRERA R., RAMOS J., GONZÁLEZ E.M., ARRESE-IGOR C., MINCHIN F.R. and
BECANA M. 2007. The Response of Carbon Metabolism and Antioxidant Defenses of
Alfalfa Nodules to Drought Stress and to the Subsequent Recovery of Plants. Plant
Physiology, 144, 1104-1114.
80 E. M. González, E. Larrainzar, R. Ladrera, C. de Miguel and C. Arrese-Igor.
ZAHRAN H.H. 1999. Rhizobium-legume symbiosis and nitrogen fixation under severe
conditions and in an arid climate. Microbiology and Molecular Biology Reviews, 63.
968-989.
Acknowledgement
Funded by grants DGI-MEC AGL2005-00274/AGR and EC FOOD-CT-2004-506223. E
Larrainzar (Formación de Profesorado Universitario), R Ladrera (Formación de Personal
Investigador) and C de Miguel (Formación de Personal Investigador) are granted by
Ministerio de Educación y Ciencia. Authors thank to Arantza Ederra, Joseba Aldasoro and
Gustavo Garijo for technical support.
Lotus Newsletter (2007) Volume 37 (2), 78 – 80.
The effect of drought on nitrogen fixation (NF) has been widely reported (see Zahran, 1999).
Among the factors, such as oxygen limitation and nitrogen feedback, a shortage in nodule
carbon flux has also been related to the inhibition of NF under drought (Arrese-Igor et al.,
1999). In these conditions, nodule sucrose synthase (SS) activity sharply declines (González
et al., 1995), thus limiting the carbon flux required for bacteroid respiration. Indeed sucrose
accumulation and malate depletion take place in nodules as a result of SS down-regulation
(González et al., 1998; Gálvez et al., 2005). Recently, by using a split root system in pea
plants, it has been shown that the cause of NF inhibition under drought is of a local origin,
rather than relying on a systemic signal (Marino et al., 2007). Key parameters of carbon
metabolism showed also a local regulation, correlated to NF inhibition, although nitrogen
feedback regulation needs to be further explored in this split root system. Both factors seem
to be crucial for the regulation of NF under drought (Ladrera et al, 2007). However, carbon
metabolism has been shown to play not such a main but a secondary role in plants of the
genus Medicago. Naya et al. (2007) concluded that a decrease in SS expression and activity,
although relevant, was not the cause of the drought-induced loss of nitrogenase activity in
alfalfa. Interestingly, a similar response has been found in the model legume Medicago
truncatula (R. Ladrera, E.M. González, and C. Arrese-Igor, unpublished data). A recent
proteome analysis (Larrainzar et al., 2007) of plant and bacteroid fractions of Medicago
truncatula root nodules under drought stress reveals that both plant and bacteroid fractions
respond simultaneously to water-deficit at the protein level. It can be inferred from the
proteomic analysis that the plant response in nodules involves a global reduction of plant
protein biosynthesis and a down-shift of cellular carbon and nitrogen metabolism and also
sulfur metabolism, thus reducing the energy-demanding process of NF. Drought response of
nodule metabolism in Lotus japonicus has not been extensively approached by now.
However, several evidences suggest that alkaline invertase could play a relevant role in
nodule carbon metabolism (Horst et al., 2007; Flemetakis et al., 2006), diminishing the
exclusive role of SS, as carbon supplier of nodule metabolism in the model legume Lotus
japonicus.
References
ARRESE-IGOR C., GONZÁLEZ E.M., GORDON A.J., MINCHIN F.R., GÁLVEZ L., ROYUELA
M., CABRERIZO P.M. and APARICIO-TEJO P.M. 1999. Sucrose synthase and nodule
78
Carbon metabolism and water stress 79
nitrogen fixation under drought and other environmental stresses. Symbiosis, 27,
189-212.
FLEMETAKIS E., EFROSE R.C., OTT T., STEDEL C., AIVALAKIS G., UDVARDI M.K. and
KATINAKIS P. 2006. Spatial and temporal organization of sucrose metabolism in Lotus
japonicus nitrogen-fixing nodules suggests a role for the elusive alkaline/neutral
invertase. Plant Molecular Biology, 62, 53-69.
GÁLVEZ L., GONZÁLEZ E.M. and ARRESE-IGOR C. 2005. Evidence for carbon flux shortage
and strong carbon/nitrogen interactions in pea nodules at early stages of water stress.
Journal of Experimental Botany, 56, 2551-2561.
GONZÁLEZ E.M., GORDON A.J., JAMES C.L. and ARRESE-IGOR C. 1995. The role of
sucrose synthase in the response of soybean nodules to drought. Journal of
Experimental Botany, 46, 1515-1523.
GONZÁLEZ E.M., APARICIO-TEJO P.M., GORDON A.J., MINCHIN F.R., ROYUELA M. and
ARRESE-IGOR C. 1998. Water-deficit effects on carbon and nitrogen metabolism of pea
nodules. Journal of Experimental Botany, 49, 1705-1714.
HORST I., WELHAM T., KELLY S., KANEKO T., SATO S., TABATA S.. PARNISKE M. and
WANG T.L. 2007. TILLING mutants of Lotus japonicus reveal that nitrogen
assimilation and fixation can occur in the absence of nodule-enhanced sucrose synthase.
Plant Physiology, 144, 806–820.
LADRERA R., MARINO D., LARRAINZAR E., GONZÁLEZ E.M. and ARRESE-IGOR C. 2007.
Reduced carbon availability to bacteroids and elevated ureides in nodules, but not
shoots, are involved in the nitrogen fixation response to early drought in soybean. Plant
Physiology, (Under review, provisionally accepted)
LARRAINZAR E., WIENKOOP S., WECKWERTH W., LADRERA R., ARRESE-IGOR C. and
GONZALEZ E.M. 2007. Medicago truncatula Root Nodule Proteome Analysis Reveals
Differential Plant and Bacteroid Responses to Drought Stress. Plant Physiology, 144,
1495–1507.
MARINO D., FRENDO P., LADRERA R., ZABALZA A., PUPPO A., ARRESE-IGOR C. and
GONZÁLEZ E.M. 2007 Nitrogen fixation control under drought stress: localized or
systemic? Plant Physiology, 143, 1968-1974.
NAYA L., LADRERA R., RAMOS J., GONZÁLEZ E.M., ARRESE-IGOR C., MINCHIN F.R. and
BECANA M. 2007. The Response of Carbon Metabolism and Antioxidant Defenses of
Alfalfa Nodules to Drought Stress and to the Subsequent Recovery of Plants. Plant
Physiology, 144, 1104-1114.
80 E. M. González, E. Larrainzar, R. Ladrera, C. de Miguel and C. Arrese-Igor.
ZAHRAN H.H. 1999. Rhizobium-legume symbiosis and nitrogen fixation under severe
conditions and in an arid climate. Microbiology and Molecular Biology Reviews, 63.
968-989.
Acknowledgement
Funded by grants DGI-MEC AGL2005-00274/AGR and EC FOOD-CT-2004-506223. E
Larrainzar (Formación de Profesorado Universitario), R Ladrera (Formación de Personal
Investigador) and C de Miguel (Formación de Personal Investigador) are granted by
Ministerio de Educación y Ciencia. Authors thank to Arantza Ederra, Joseba Aldasoro and
Gustavo Garijo for technical support.
Lotus Newsletter (2007) Volume 37 (2), 81 – 83.
81
82 F. Escaraay, J. Pesqueira, F. Damiani, F. Paolocci, P. Carrasco Sorli and O.A. Ruiz
and L. tenuis plants exposed to salinity, while this parameter increased by 27% in L.
filicaulis plants.
References
BARRY T.N. and MANLEY T.R. 1986. Interrelationships between the concentrations of total
condensed tannin, free condensed tannin and lignin in Lotus sp. and their possible
consecuences in ruminant nutrition. Journal of the Science of Food and Agriculture, 37,
248-254.
DIXON R.A. and PAIVA N.L. 1995. Stress-induced phenylpropanoid metabolism. The Plant
Cell, 7, 1085-1097.
FOO L.Y., NEWMAN R., WAGHORN G., MCNABB W.C. and ULYATT M.J. 1996.
Proanthocyanidins from Lotus corniculatus. Phytochemistry, 41, 617-624.
GEBREHIWOT L., BEUSELINCK P.R. and ROBERTS C.A. 2002. Seasonal variations in
condensed tannin concentration of three Lotus species. Agronomy Journal, 94,
1059-1065.
LI YU-GUANG, TANNER G. and LARKIN P. 1996. The DMACA-HCl protocol and the
threshold proanthocyanidin content for bloat safety in forage legumes. Journal of the
Science of Food and Agriculture, 70, 89-101.
NIEZEN J.H., WAGHORN T.S., WAGHORN C.G. and CHARLESTON W.A.G. 1995. Growth
and gastrointestinal nematode parasitism in lambs grazing either Lucerne (medicago
sativa) or sulla (Hedysarum coronarium) which contains condensed tannins Journal of
agricultural cience, 125 (2), 281-289.
OTERO M.J. and HIDALGO L.G. 2004. Taninos condensados en especies forrajeras de clima
templado: efectos sobre la productividad de rumiantes afectados por parasitosis
gastrointestinales (una revisión) Livestock Research for Rural Development, 16 (2). Art.
#13.
PANCKURST C.E. and JONES W.T. 1979. Effectiveness of Lotus root nodules. Journal of
Experimental Botany, 30, 1095-1107.
PAOLOCCI F., BOVONE T., TOSTI N., ARCIONI S. and DAMIANI F. 2005. Light and an
exogenous transcription factor qualitatively and quantitatively affect the biosynthetic
pathway of condensed tannins in Lotus corniculatus leaves. Journal of Experimental
Botany, 56, 1093-1103.
REINOSO H., SOSA L., RAMÍREZ L. and LUNA V. 2004. Salt-induced changes in the
vegetative anatomy of Prosopis strombulifera (Leguminosae). Canadian Journal of
Botany 82 (5), 618-628.
Tannins in saline stress 83
SIVAKUMARAN S., RUMBALL W., LANE G.A., FRASER K., FOO L.Y., YU M. and
MEAGHER P. 2006. Variation of Proanthocyanidins in Lotus Species. Journal of
Chemical Ecology, 32, 1797-1816.
WAGHORN C.G. and SHELTON I.D. 1997. Effect of condensed tannins in Lotus corniculatus
on the nutritive value of pasture for sheep. Journal of Agricultural Science, 128,
365-372.
Lotus Newsletter (2007) Volume 37 (2), 84-85.
Condensed tannins (CTs), also known as proanthocyanidins (PAs), are plant secondary
metabolites that share most of their biosynthetic pathway with anthocyanins. CTs are
polymeric flavonoids composed primarly of epicatechin and/or catechin units. They act as
antioxidants with beneficial effects on human and animal health. In planta, CTs act as
protective agents against pathogens, pests and diseases and control seed permeability and
dormancy. These compounds strongly affect plant quality traits: the palatability and nutritive
value of forage legumes are highly influenced by their concentration and structure. High
concentrations of CTs can decrease the palatability and digestibility of plants. Conversely,
moderate quantities of CTs (2-4% dry matter) in forage prevent proteolysis during ensiling
and rumen fermentation, thereby protecting ruminants against pasture bloat (Tanner, 2004).
Unfortunately, CTs are not accumulated in leaves of the most valuable forage species such
as alfalfa and clovers. The genus Lotus offers a wide range of options for studying the
regulation of CTs as it includes species which accumulate CTs only in flowers and stems (L.
japonicus, L. tenuis) or in flower, stems and leaves (L. corniculatus). Equally interesting is
that, as opposed to Arabidopsis that has yielded critical information regarding the
transcriptional control of genes involved in CT biosynthesis in seed coats, in L. corniculatus
and L. japonicus CT polymers are synthesised from both epicatechin and catechin starter
units and not only from epicatechin. We aimed to understand the genetic and environmental
determinants controlling leaf CT accumulation in L. corniculatus. To this purpose, either
partial or full length cDNAs from the structural genes of the CT pathways (PAL, CHS, DFR,
ANS, ANR, LAR1 and LAR2) were cloned. Their expression patterns were studied under
different growth conditions and in different genetic backgrounds resulting from the
transformation of wild type genotypes, polymorphic for the levels of leaf CTs, with
exogenous regulators of anthocyanins belonging either to the bHLH or MYB gene families.
More specifically, here we show that in L. corniculatus it is possible to specifically up- and
down-regulate leaf CT biosynthesis using heterologous activator/repressor genes, without
inducing significant alteration on levels of other flavonoid end products. We also show that
the epicatechin (via ANR) and catechin (via LAR) branches of the CT pathways are subjected
to a coordinate transcriptional regulation (Paolocci et al., 2007). Strategies to switch on the
CT pathway in legume species that don’t synthesize these polymers in leaves are also
discussed.
Título abreviado del resúmen 85
References
TANNER G.J. 2004. Condensed Tannins. In Davies K.M. (Ed). Plant pigments and their
manipulation. Annual plant reviews Vol 12. Blackwell Publishing-CRC press, Boca
Raton, FL, USA pp 150-184.
PAOLOCCI F., ROBBINS M.P., MADEO L., ARCIONI S., MARTENS S. and DAMIANI F. 2007.
Ectopic expression of a bHLH gene transactivates parallel pathways of
proanthocyanidin (PA) biosynthesis. Structure, expression analysis and genetic control
of LAR and ANR genes in Lotus corniculatus. Plant Physiology, 143, 504-516.
Lotus Newsletter (2007) Volume 37 (2), 86.
*
Corresponding author click here for Spanish version
The genus Lotus includes numerous endemic species in the Canary Islands. They usually
show an island distribution pattern, which is exclusive of single Island and has a reduced
area, being many of them threatened or in danger of extinction. The rhizobia were obtained
from root nodules of plants collected from their native locations. When this was not
possible due to the reduced number of specimens, germinated seeds or cuttings were used
as tramp-plant on soils where the wild populations were growing. In this study the rhizobia
were isolated from L. callis-viridis, L. kunkelii and L. arinagensis in Gran Canaria Island,
from L. berthelotii, L. sessilifolius and L campylocladus in Tenerife, from L. pyranthus in
La Palma and from L. lancerottensis in Lanzarote. The isolates were characterized through
their restriction patterns and sequencing of the 16S ribosomal DNA and the symbiotic gene
nodC. The results showed a great diversity among the rhizobia nodulating the different
Lotus species in the Canary Islands, finding that they belong to different species from the
genera Mesorhizobium, Sinorhizobium and Rhizobium. The genus Mesorhizobium was
more frequently isolated, appearing in all the Lotus species tested. This rhizobia genus was
represented by genotypes that belong to several different species, many of which may
constitute new species for this genus. In general, the genotypes detected did not correlate
with a particular Lotus species nor with a single Island, although some seem to correlate
with a particular environment. Thus, one genotype dominated in the halopsamophile
environments. Symbiotic genes do not correlate with the rhizobial classification and
intrageneric horizontal gene transfer seems to be a usual phenomenon in these natural
environments.
86
Lotus Newsletter (2007) Volume 37 (2), 87 – 88.
In polluted soils the presence of toxic inorganic compounds such as heavy metals has an
important impact on the resident microflora, which seems to be much less varied in polluted
areas. In last years, our group has been involved in projects aimed to evaluate the harmful
effects of long term heavy metals contamination of soils on the Rhizobium-legume
symbiosis, mainly those ones with R. leguminosarum bv. trifolii and Trifolium sp. (Castro et
al., 1997; 2003). An important activity for regeneration soils polluted by industrial activities
is the establishment of vegetation. Leguminous plants can have, here, an important role due
their interesting agricultural potential, their capacity to fix atmospheric nitrogen and
adaptation to low input agricultural systems. Particularly in the case of Lotus species, some
of them are present in rather extreme conditions such as those existing in contaminated soils.
The aim of this work was to examine the effects of soil pollution on the genetic and
phenotypic characteristics of rhizobial population isolated from Lotus sp. growing in
contaminated soils (mainly with Hg and As). The soils were selected from an industrial area
with known environmental pollution problems, where heavy metals and other pollutants
have been emitted for nearly 40 years. This area is particularly affected by the release of
liquid effluents from fertilizer and chemical industries. Taking in account that symbiotic
interactions between species of the genus Lotus and Rhizobium strains can be effective,
ineffective or parasitic according with to combination, nodulation tests were evaluated with
different lotus species. Several parameters were also analysed such as population size,
nitrogen fixation capacity, genetic diversity and mercury and arsenic tolerance. The results
suggested that some of the Lotus/Rhizobium symbioses seem to be particularly well adapted
to adverse environmental conditions and can be an adequate tool for bioremediation of
polluted soils.
References
CASTRO I.V., FERREIRA E.M. and MCGRATH S.P. 1997. Effectiveness and genetic diversity
of Rhizobium leguminosarum bv. trifolii isolates in portuguese soils polluted by
industrial effluents. Soil Biology & Biochemistry, 29, 1209-1213.
87
88 I. Videira E Castro, P. Sá-Pereira, F. Simões, J.A. Matos and E. Ferreira
CASTRO I.V., FERREIRA E.M. and MCGRATH S.P. 2003. Survival and plasmid stability of
rhizobia introduced into a contaminated soil. Soil Biology and Biochemistry, 35, 49-54.
Many microorganisms form symbioses with plants that range, on a continuous scale, from
parasitic to mutualistic. Among these, the most widespread mutualistic symbiosis is the
arbuscular mycorrhiza (AM), formed between some soil-borne fungi (AM fungi) belonging
to the phylum of the Glomeromycota and most vascular flowering plants. These associations
occur in terrestrial ecosystems throughout the world and have a global impact on plant
mineral nutrition and health, as well as on the structure of plant communities. The main
physiological basis for mutualism in the AM symbiosis is bi-directional nutrient transfer.
The plant supplies the fungus with carbon (from its fixed photosynthates) while the fungus
assists the plant on its uptake of mineral nutrients from the soil. During the root colonization
process, the AM hyphal branches penetrate the cortical cell wall and differentiate within
these cells to form highly branched structures, known as arbuscules. These fungal structures,
which establish a large surface of contact with the plant protoplast, play a key role in
reciprocal nutrient exchange between the plant cells and the AM fungal symbiont.
Simultaneously to intraradical colonization, the fungus develops an extensive network of
hyphae in the soil surrounding the root. This extraradical mycelium explores and exploits
soil microhabitats for nutrient acquisition and its function is critical for the absorption low
mobility nutrients, mainly phosphorus, ammonium, and some micronutrients such as copper
and zinc. AM fungi, as obligate symbionts, rely on the plant host for the supply of carbon
assimilates required for their growth, maintenance and function. Development of this highly
compatible association requires the coordinate molecular and cellular differentiation of both
symbionts to form specialized interfaces over which bi-directional nutrient transfer occurs.
Despite the agronomic and ecological importance of the AM symbiosis, the molecular and
cellular events associated with the establishment and functioning of the association are
poorly understood. Progress in understanding the genetic and molecular basis of this
important symbiotic association has been hampered by the obligate biotrophy of the fungal
partner, the difficulties to isolate the intraradical fungal structures and by the lack of
mycorrhiza formation on the plant model species Arabidopsis thaliana. In recent decades,
the use of legume plants, such as Medicago truncatula and Lotus japonicus, as experimental
systems for research of the AM symbiosis, as well as the application of powerful molecular
techniques to study the genome of AM fungi has increased our understanding of the
molecular mechanisms underlying bi-directional nutrient transport processes in a
mycorrhizal plant. Current knowledge on the mechanisms of phosphate and nitrogen uptake
89
90 N. Ferrol
and transport by AM fungi as well as on carbon transfer from the plant to the fungus will be
presented.