Issue date: 19 February 2002
Researchers studying plant behaviour have discovered similarities between the processes preventing plants from wilting and humans from suffering impotence. Data recently published by the University of the West of England shows the same chemical chain of events is involved in both situations – and has led to an understanding of how water loss from plants might be reduced.
This blocking action has parallels with the chemical effect of impotence treatments in humans. Plants lose water through their stomata, small pores surrounded by guard cells, that cover the leaves. The signals governing the opening and closing of a plant’s stomata are closely allied to the way human blood vessels contract and relax to control blood flow.
The key finding of the research concerns the role played by nitric oxide in the closure of the plant’s stomata. Researchers from UWE’s Faculty of Applied Sciences demonstrated this in a series of experiments in which chemicals to ‘scavenge’ nitric oxide or inhibit its action were added. The reaction of the cells could be clearly measured under the microscope. In other tests, fluorescent dyes that react to the presence of nitric oxide were added to show the effect of different ‘scavengers’ on the guard cells under a special confocal microscope.
This discovery could have wide practical implications for developing drought- resistant plants for areas of the world suffering severe water shortages. Possible ways of achieving this include selective breeding or by the addition of agrochemicals acting as a form of Viagra for plants.
“It has been known for some time that a stress hormone called abscisic acid or ABA is activated in plants under certain conditions such as drought,” said lead researcher Dr Steve Neill, of UWE’s Centre for Research in Plant Science.
“What wasn’t clear before was the important role played by nitric oxide. This substance, well-known as a signal molecule in humans, is made in response to ABA and causes the formation of a messenger molecule that acts inside the guard cells. This offers a new opportunity to manipulate a plant’s water requirements which could impact significantly on crop productivity.”
The findings of the research team have just been published in the Scientific Correspondence section of Plant Physiology, January 2002, Vol. 128, pp.13–16. Full text can be accessed at www.plantphysiol.org