Molecular and Cellular Aspects of Calcium in Plant Development, 1986
In recent years it has become apparent that the calcium ion plays a key regulatory role in plant ... more In recent years it has become apparent that the calcium ion plays a key regulatory role in plant cell metabolism. The details of the molecular events which contribute to this function are beginning to emerge. In animals it has been convincingly demonstrated that a common response to a variety of cell surface stimuli is a transient increase in cytoplasmic calcium concentration (Rasmussen & Barrett 1984). These alterations in cytoplasmic calcium concentration are interpreted by a number of calcium binding proteins. Of these the best characterized is calmodulin which has also been shown to participate in a variety of physiological processes in higher plants (Dieter, 1984). Other calcium binding proteins include enzymes whose activity is modulated by physiological concentrations of calcium. Among these enzymes, the protein kinases because of their known regulatory function are potentially of great importance in plant cells.
It is often claimed by proponents of organic farming that, if used worldwide, it would provide su... more It is often claimed by proponents of organic farming that, if used worldwide, it would provide sufficient food for a growing world population. Here we make a critical assessment of this claim for wheat, a major cereal crop and source of food throughout the world. We have compared organic and conventional systems, examined some of the publications and claims in detail, and found a typical ratio of organic:conventional wheat yields of 0.65. Nitrogen (N) fixation by legumes, the main source of N supply in organic systems, is shown to be much too small and variable to support large and consistent wheat yields. Our conclusion agrees with that of a recent report by the University of Reading’s Centre for Agricultural Strategy that organic agriculture cannot feed the world using current technologies. However, we believe that there is a need to reduce the over-optimal use of fertilisers and agricultural chemicals and to better manage crop rotations to reduce nutrient losses to the environmen...
The control of development is often viewed as a simple process which can be approached experiment... more The control of development is often viewed as a simple process which can be approached experimentally in an equally simple fashion. However metabolism, cells, tissues and indeed whole plants form networks with a great density of connections. The control of complicated networks is little understood and their behaviour on perturbation is usually counter-intuitive. The notions of 'limiting factors' and 'cause and…
Nucleic Acids and Protein Synthesis in Plants, 1977
A substantial majority of animal hormones have their biological effects mediated by theadenyl cyc... more A substantial majority of animal hormones have their biological effects mediated by theadenyl cyclase system (1)0 Until Kuo and Greengard (2) produced their unifying theory it was not clear how cyclic AMP initiated the subsequent molecular events associated with hormone action. Their theory (2.) proposed that the effects of cyclic AMP were mediated by cyclic AMP-dependent protein kinases in the responsive tissue. Since it is the catalytic function of protein kinases to phosphorylate proteins, this theory places our understanding of hormone action firmly on knowing which cellular proteins are phosphorylated. The list of known phosphorylated protein is very extensive and covers proteins in all of the major cellular groups (3). Evidence that phosphorylation (or dephos-phorylation) modifies the biological activity of the phosphorylated protein has however only been critically demonstrated in a few cases (3). Despite the apparent absence of cyclic AMP in plants, this field of research offers such considerable promise for dissecting out the regulatory systems of plants that its study can hardly be avoided.
Concerns over the sustainable future of mankind centre on population increase, food production an... more Concerns over the sustainable future of mankind centre on population increase, food production and global warming. There are enormous uncertainties about food production for a projected nine billion people and whether a rightful desire to remove poverty, the scourge of disease and food insecurity will result in increased greenhouse gas (GHG) emissions. The level of future oil reserves remain uncertain and some countries wish to remove dependence on imported fossil fuel. By recycling carbon through biofuel, emissions could be reduced and dependence minimised.
The incorporation of science and technology into agriculture has led to enormous growth in crop y... more The incorporation of science and technology into agriculture has led to enormous growth in crop yields, providing food security in many countries. From the 1950s onwards there has been increasing interference in agricultural policy by a few scientists who are marginal to agriculture and from a variety of unqualified groups. These groups and individuals have used fear and anxiety and have greatly exaggerated minor problems to persuade an unqualified public of supposed dangers in food and to try and change agricultural policy. Fear and emotion do not lead to good policy, and the cult of the amateur that has developed could have serious repercussions on vital food security and future agriculture in developing countries; it must be soundly rejected.
Symposia of the Society for Experimental Biology, 1986
This article argues that the basic function for growth substance is resource allocation under poo... more This article argues that the basic function for growth substance is resource allocation under poor growth conditions. The following scheme is suggested. Plants in the wild frequently suffer a paucity of resources which result from interplant competition and ecological and local environmental variation. The strategy adopted by many plants particularly ruderals (from which crops may have evolved) to help mitigate these problems is phenotypic plasticity; the growth of the plant body is adjusted to best exploit the scarce resources and help achieve desirable growth and reproductive goals. Phenotypic plasticity requires decisions to be made concerning the diversion of scarce growth resources to one facet of development rather than another; for example, to height or leaf area rather than thickness; or, between tissues, stem rather than leaves. Growth substances are coupled to these individual facets of development. They represent a simple way in which the extent of resource diversion can ...
Molecular and Cellular Aspects of Calcium in Plant Development, 1986
In recent years it has become apparent that the calcium ion plays a key regulatory role in plant ... more In recent years it has become apparent that the calcium ion plays a key regulatory role in plant cell metabolism. The details of the molecular events which contribute to this function are beginning to emerge. In animals it has been convincingly demonstrated that a common response to a variety of cell surface stimuli is a transient increase in cytoplasmic calcium concentration (Rasmussen & Barrett 1984). These alterations in cytoplasmic calcium concentration are interpreted by a number of calcium binding proteins. Of these the best characterized is calmodulin which has also been shown to participate in a variety of physiological processes in higher plants (Dieter, 1984). Other calcium binding proteins include enzymes whose activity is modulated by physiological concentrations of calcium. Among these enzymes, the protein kinases because of their known regulatory function are potentially of great importance in plant cells.
It is often claimed by proponents of organic farming that, if used worldwide, it would provide su... more It is often claimed by proponents of organic farming that, if used worldwide, it would provide sufficient food for a growing world population. Here we make a critical assessment of this claim for wheat, a major cereal crop and source of food throughout the world. We have compared organic and conventional systems, examined some of the publications and claims in detail, and found a typical ratio of organic:conventional wheat yields of 0.65. Nitrogen (N) fixation by legumes, the main source of N supply in organic systems, is shown to be much too small and variable to support large and consistent wheat yields. Our conclusion agrees with that of a recent report by the University of Reading’s Centre for Agricultural Strategy that organic agriculture cannot feed the world using current technologies. However, we believe that there is a need to reduce the over-optimal use of fertilisers and agricultural chemicals and to better manage crop rotations to reduce nutrient losses to the environmen...
The control of development is often viewed as a simple process which can be approached experiment... more The control of development is often viewed as a simple process which can be approached experimentally in an equally simple fashion. However metabolism, cells, tissues and indeed whole plants form networks with a great density of connections. The control of complicated networks is little understood and their behaviour on perturbation is usually counter-intuitive. The notions of 'limiting factors' and 'cause and…
Nucleic Acids and Protein Synthesis in Plants, 1977
A substantial majority of animal hormones have their biological effects mediated by theadenyl cyc... more A substantial majority of animal hormones have their biological effects mediated by theadenyl cyclase system (1)0 Until Kuo and Greengard (2) produced their unifying theory it was not clear how cyclic AMP initiated the subsequent molecular events associated with hormone action. Their theory (2.) proposed that the effects of cyclic AMP were mediated by cyclic AMP-dependent protein kinases in the responsive tissue. Since it is the catalytic function of protein kinases to phosphorylate proteins, this theory places our understanding of hormone action firmly on knowing which cellular proteins are phosphorylated. The list of known phosphorylated protein is very extensive and covers proteins in all of the major cellular groups (3). Evidence that phosphorylation (or dephos-phorylation) modifies the biological activity of the phosphorylated protein has however only been critically demonstrated in a few cases (3). Despite the apparent absence of cyclic AMP in plants, this field of research offers such considerable promise for dissecting out the regulatory systems of plants that its study can hardly be avoided.
Concerns over the sustainable future of mankind centre on population increase, food production an... more Concerns over the sustainable future of mankind centre on population increase, food production and global warming. There are enormous uncertainties about food production for a projected nine billion people and whether a rightful desire to remove poverty, the scourge of disease and food insecurity will result in increased greenhouse gas (GHG) emissions. The level of future oil reserves remain uncertain and some countries wish to remove dependence on imported fossil fuel. By recycling carbon through biofuel, emissions could be reduced and dependence minimised.
The incorporation of science and technology into agriculture has led to enormous growth in crop y... more The incorporation of science and technology into agriculture has led to enormous growth in crop yields, providing food security in many countries. From the 1950s onwards there has been increasing interference in agricultural policy by a few scientists who are marginal to agriculture and from a variety of unqualified groups. These groups and individuals have used fear and anxiety and have greatly exaggerated minor problems to persuade an unqualified public of supposed dangers in food and to try and change agricultural policy. Fear and emotion do not lead to good policy, and the cult of the amateur that has developed could have serious repercussions on vital food security and future agriculture in developing countries; it must be soundly rejected.
Symposia of the Society for Experimental Biology, 1986
This article argues that the basic function for growth substance is resource allocation under poo... more This article argues that the basic function for growth substance is resource allocation under poor growth conditions. The following scheme is suggested. Plants in the wild frequently suffer a paucity of resources which result from interplant competition and ecological and local environmental variation. The strategy adopted by many plants particularly ruderals (from which crops may have evolved) to help mitigate these problems is phenotypic plasticity; the growth of the plant body is adjusted to best exploit the scarce resources and help achieve desirable growth and reproductive goals. Phenotypic plasticity requires decisions to be made concerning the diversion of scarce growth resources to one facet of development rather than another; for example, to height or leaf area rather than thickness; or, between tissues, stem rather than leaves. Growth substances are coupled to these individual facets of development. They represent a simple way in which the extent of resource diversion can ...
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