Study sheds light on plants natural defence mechanism

Researchers have discovered how plants protect their leaves from damage by sunlight when they are faced with extreme climates.

London, Nov 22 : Researchers have discovered how plants protect their leaves from damage by sunlight when they are faced with extreme climates.

The process of photosynthesis in plants relies upon the efficient collection of sunlight. Photosynthesis can work even at low levels of sunlight, when plants are in the shade or under cloud cover for example.

However, when the sun is very bright or when it is cold or very dry, the level of light energy absorbed by leaves can be greatly in excess of that which can be used in photosynthesis and can destroy the plant.

But for protection against harmful sunlight, plants employ a remarkable process called photoprotection, in which a change takes place in the leaves so that the excess light energy is converted into heat, which is harmlessly dispersed.

The study, led by the researchers from University of Sheffield and Queen Mary, University of London, have determined how this process of photoprotection works.

From the study, the scientists were able to show how a small number of certain key molecules, hidden among the millions of others in the plant leaf, change their shape when the amount of light absorbed is excessive.

They have been able to track the conversion of light energy to heat that occurs in less than a billionth of a second.

Professor Horton, of the University of Sheffield's Department of Molecular Biology and Biotechnology, who lead the UK team, said that the findings were important in developing plants with improved photoprotective mechanisms to enable them to better cope with climate change.

"These results are important in developing plants with improved photoprotective mechanisms to enable them to better cope with climate change," Nature quoted Horton, as saying.

The finding might also have implications both for adapting plants to the threat of global warming and for helping man better harness solar energy.

"This may be hugely significant in our fight against global warming. It is a fantastic example of what can be achieved in science when the skills of biologists and physicists are brought together," Horton said.

Moreover, there are other global implications of this research.

Dr Alexander Ruban of Queen Mary's School of Biological and Chemical Sciences, said: "As we seek to develop new solar energy technology it will be important to not only understand, but to mimic the way biology has learnt to optimise light collection in the face of the continually changing intensity of sunlight."

The study appears in Nature magazine.

ANI