Success in the shade
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CTA. 1994. Success in the shade. Spore 54. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/49526
Using a totally new approach British scientists have produced genetically engineered plants which may lead to the development of crops which produce better. This breakthrough, made by a team at Leicester University stops plants competing with each...
Using a totally new approach British scientists have produced genetically engineered plants which may lead to the development of crops which produce better. This breakthrough, made by a team at Leicester University stops plants competing with each other for light so that they put more effort into producing seeds, fruits, leaves and roots. This may mean that more plants will reach their full yield and may enable crops to be sown more densely, thereby increasing field productivity. Crop plants normally avoid shade by elongating their stems. In doing so, they utilize energy which might otherwise have gone to the economically important part of the plant, such as the seeds or fruit. The effects of shading on wheat plants by, for instance, a nearby woodland can be measured up to 50 metres away. The shade-avoidance response is actually a response to the presence of far red light, the wavelength of which is too long to be visible to the human eye. When plants grow closely together, this far red light is reflected from them. Receptors in the plants which receive this reflected light trigger the production of phytochrome B, which stimulates the plants to grow upwards. In natural conditions this may give the plant a competitive advantage, but in a cultivated crop it simply leads to unproductive growth as the plants try to outgrow each other. Scientists have found a gene in oats that overcomes the response. It produces a closely related protein called phytochrome A, which inhibits straggly stem growth in the presence of the~light reflected from neighbours. In oats the gene is suppressed by other genes. But the scientists have developed a way of overriding this so it is permanently switched on. Although there is still some work to be done scientists are confident that this discovery has great potential. Professor H Smith Botany Department University of Leicester University Road Leicester LE1 7RH UK