A greenhouse pot experiment with different phosphorus supply was conducted to study growth, photo... more A greenhouse pot experiment with different phosphorus supply was conducted to study growth, photosynthesis and free polyamine (PA) content in Plantago lanceolata L. plants in relation to arbuscular mycorrhizal (AM) colonization. Inoculum of Glomus fasciculatum (BEG 53) was used. Inoculated plants had high colonization intensities which were related to the P supply. Non-mycorrhizal (NM) plants showed a typical yield response curve for P availability. Dry masses of mycorrhizal (M) plants were higher at the lowest soil P content than those of NM plants, but the opposite was found at the highest P supply. P contents in M plants were always higher. There were no differences in chlorophyll (Chl) concentrations (except the lowest soil P content) and ratios of variable to maximum Chl fluorescence (Fv/Fm) values between M and NM plants, whereas M plants had higher ratios of leaf area to fresh mass (A/f.m.) at low soil P contents and they had significantly higher CO2 fixation capacities per unit leaf area. Free putrescine (Put), spermidine (Spd) and spermine (Spm) contents in NM plants were usually highest at the lowest P supply. The ratios of Put/(Spd+Spm) were identical in M and NM leaves. They were significantly higher, however, in NM roots at the two low P doses. It is concluded, that a P nutritional status might exist, below which PA concentrations and ratio are increased drastically, possibly indicating P deficiency or a certain state of plant development with a higher demand for AM symbiosis.
The modified nucleotide content of the ribosomal RNAs in wheat is greatly influenced by light. Th... more The modified nucleotide content of the ribosomal RNAs in wheat is greatly influenced by light. The rRNAs of etiolated seedlings contain far fewer modified derivatives. The modified nucleotide composition characteristic of green plants develops gradually as a result of irradiation. In the course of the experiments changes in the state of modification of 5.8S and 18S rRNAs were examined during the greening of etiolated wheat seedlings. Three types of minor nucleotides, O2′-methyladenosine, O2′-methylguanosine and pseudouridine were found in the 5.8S rRNA of green wheat leaves, none of which was detected in etiolated wheat. The minor nucleotides appeared in the 5.8S rRNA only after 48 h irradiation. The sequences of 5.8S rDNA, TTS1, ITS2 and 18S rDNA were also determined and the presence of the hyper-modified nucleotide 1-methyl-3-(α-amino-α-carboxypropyl)-pseudouridine was detected in green wheat 18S rRNA. This minor component was not demonstrable in etiolated wheat 18S rRNA, but appeared after irradiation for 48 h.
... Zoltán Bratek1, Ibolya Vörös2, Tünde Takács2, István Parádi1, Szabolcs Rudnóy1, Krisztián Hal... more ... Zoltán Bratek1, Ibolya Vörös2, Tünde Takács2, István Parádi1, Szabolcs Rudnóy1, Krisztián Halász1* ... We isolated monosporic arbuscular-mycorrhizal fungi strains from a number of soil types (brown forest soil and carbonated field soil) in the Balaton drainage basin. ...
ITS regions (internal transcribed spacers—ITS1 andITS2—with the 5.8S gene of the nuclear rDNA) of... more ITS regions (internal transcribed spacers—ITS1 andITS2—with the 5.8S gene of the nuclear rDNA) of 25 fruit body samples ofTerfezia terfezioides, originating from Hungary and Italy, were compared. The amplification and sequencing of the ITS region was successful with both theITS1-ITS4 andITSIF-ITS4 primer pairs. No differences of the restriction fragment length polymorphism profiles were detected among 19 samples collected in one place at the same time. The sequences of the ITS region of 9 samples collected in different localities were highly invariable, differing in only two bases. Thus the intraspecific homogeneity of the ITS region seems to be an important species-specific characteristic ofT. terfezioides in contrast to otherTerfezia species. As the samples of the species were collected from different and distant localities of Europe, the ITS sequence ofT. terfezioides can be considered a very conservative, reliable molecular marker of the fungus. *** DIRECT SUPPORT *** A00EN076 00008
Several taxonomic problems arise in the group of small, white European truffles, probably due to ... more Several taxonomic problems arise in the group of small, white European truffles, probably due to the over-emphasized significance of certain morphological features of ascomata. The distinction between Tuber rapaeodorum Tul. & C. Tul. and Tuber borchii Vittad. and Tuber puberulum Berk. & Broome has not been accepted in several recent studies. Furthermore, the existence of T. rapaeodorum been questioned in some recent synopses of the genus. We conducted microscopic and ITS sequence investigations of 31 herbarium specimens. Using morphological features such as peridium structure, form and size of spores and dermatocystidia and spore numbers per ascus, we could distinguish T. borchii, T. foetidum Vittad., T. maculatum Vittad., Tuber puberulum, and T. rapaeodorum. Analysis of whole ITS sequences showed sharp differences among the morphologically separated groups. Neighbour-joining and parsimony methods produced highly supported branches and confirmed the identity of these species.
In the present paper we report a mycorrhizal association between the hypogeous white truffle Ter... more In the present paper we report a mycorrhizal association between the hypogeous white truffle Terfezia terfezioides and the black locust (Robinia pseudoacacia) growing at various sites in Hungary. The mycorrhiza can be considered as being of the endo- or ectendo-type, since both mantle and Hartig net are absent. Morphological features of the septate hyphae colonizing cortical root cells were investigated by light microscopy on cryosections and on ultra-thin sections studied by transmission electron microscopy. Artificial infection of micropropagated black locust plantlets with the mycelium of the fungus was successful and had the same characteristics as naturally occurring associations.
A greenhouse pot experiment with different phosphorus supply was conducted to study growth, photo... more A greenhouse pot experiment with different phosphorus supply was conducted to study growth, photosynthesis and free polyamine (PA) content in Plantago lanceolata L. plants in relation to arbuscular mycorrhizal (AM) colonization. Inoculum of Glomus fasciculatum (BEG 53) was used. Inoculated plants had high colonization intensities which were related to the P supply. Non-mycorrhizal (NM) plants showed a typical yield response curve for P availability. Dry masses of mycorrhizal (M) plants were higher at the lowest soil P content than those of NM plants, but the opposite was found at the highest P supply. P contents in M plants were always higher. There were no differences in chlorophyll (Chl) concentrations (except the lowest soil P content) and ratios of variable to maximum Chl fluorescence (Fv/Fm) values between M and NM plants, whereas M plants had higher ratios of leaf area to fresh mass (A/f.m.) at low soil P contents and they had significantly higher CO2 fixation capacities per unit leaf area. Free putrescine (Put), spermidine (Spd) and spermine (Spm) contents in NM plants were usually highest at the lowest P supply. The ratios of Put/(Spd+Spm) were identical in M and NM leaves. They were significantly higher, however, in NM roots at the two low P doses. It is concluded, that a P nutritional status might exist, below which PA concentrations and ratio are increased drastically, possibly indicating P deficiency or a certain state of plant development with a higher demand for AM symbiosis.
The modified nucleotide content of the ribosomal RNAs in wheat is greatly influenced by light. Th... more The modified nucleotide content of the ribosomal RNAs in wheat is greatly influenced by light. The rRNAs of etiolated seedlings contain far fewer modified derivatives. The modified nucleotide composition characteristic of green plants develops gradually as a result of irradiation. In the course of the experiments changes in the state of modification of 5.8S and 18S rRNAs were examined during the greening of etiolated wheat seedlings. Three types of minor nucleotides, O2′-methyladenosine, O2′-methylguanosine and pseudouridine were found in the 5.8S rRNA of green wheat leaves, none of which was detected in etiolated wheat. The minor nucleotides appeared in the 5.8S rRNA only after 48 h irradiation. The sequences of 5.8S rDNA, TTS1, ITS2 and 18S rDNA were also determined and the presence of the hyper-modified nucleotide 1-methyl-3-(α-amino-α-carboxypropyl)-pseudouridine was detected in green wheat 18S rRNA. This minor component was not demonstrable in etiolated wheat 18S rRNA, but appeared after irradiation for 48 h.
... Zoltán Bratek1, Ibolya Vörös2, Tünde Takács2, István Parádi1, Szabolcs Rudnóy1, Krisztián Hal... more ... Zoltán Bratek1, Ibolya Vörös2, Tünde Takács2, István Parádi1, Szabolcs Rudnóy1, Krisztián Halász1* ... We isolated monosporic arbuscular-mycorrhizal fungi strains from a number of soil types (brown forest soil and carbonated field soil) in the Balaton drainage basin. ...
ITS regions (internal transcribed spacers—ITS1 andITS2—with the 5.8S gene of the nuclear rDNA) of... more ITS regions (internal transcribed spacers—ITS1 andITS2—with the 5.8S gene of the nuclear rDNA) of 25 fruit body samples ofTerfezia terfezioides, originating from Hungary and Italy, were compared. The amplification and sequencing of the ITS region was successful with both theITS1-ITS4 andITSIF-ITS4 primer pairs. No differences of the restriction fragment length polymorphism profiles were detected among 19 samples collected in one place at the same time. The sequences of the ITS region of 9 samples collected in different localities were highly invariable, differing in only two bases. Thus the intraspecific homogeneity of the ITS region seems to be an important species-specific characteristic ofT. terfezioides in contrast to otherTerfezia species. As the samples of the species were collected from different and distant localities of Europe, the ITS sequence ofT. terfezioides can be considered a very conservative, reliable molecular marker of the fungus. *** DIRECT SUPPORT *** A00EN076 00008
Several taxonomic problems arise in the group of small, white European truffles, probably due to ... more Several taxonomic problems arise in the group of small, white European truffles, probably due to the over-emphasized significance of certain morphological features of ascomata. The distinction between Tuber rapaeodorum Tul. & C. Tul. and Tuber borchii Vittad. and Tuber puberulum Berk. & Broome has not been accepted in several recent studies. Furthermore, the existence of T. rapaeodorum been questioned in some recent synopses of the genus. We conducted microscopic and ITS sequence investigations of 31 herbarium specimens. Using morphological features such as peridium structure, form and size of spores and dermatocystidia and spore numbers per ascus, we could distinguish T. borchii, T. foetidum Vittad., T. maculatum Vittad., Tuber puberulum, and T. rapaeodorum. Analysis of whole ITS sequences showed sharp differences among the morphologically separated groups. Neighbour-joining and parsimony methods produced highly supported branches and confirmed the identity of these species.
In the present paper we report a mycorrhizal association between the hypogeous white truffle Ter... more In the present paper we report a mycorrhizal association between the hypogeous white truffle Terfezia terfezioides and the black locust (Robinia pseudoacacia) growing at various sites in Hungary. The mycorrhiza can be considered as being of the endo- or ectendo-type, since both mantle and Hartig net are absent. Morphological features of the septate hyphae colonizing cortical root cells were investigated by light microscopy on cryosections and on ultra-thin sections studied by transmission electron microscopy. Artificial infection of micropropagated black locust plantlets with the mycelium of the fungus was successful and had the same characteristics as naturally occurring associations.
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