Findings on plant breathing pattern will help lessen water needs

The tighter a plant can keep its pores,the less water it loses and the less water it requires to grow. And since carbon dioxide levels are 40 per cent greater than in preindustrial times,it would seem that plants could now get plenty of carbon dioxide with out losing too much water — an odd and perhaps beneficial consequence of the accumulation of greenhouse gases.

“Normally for every CO2 molecule a plant takes in,the plant loses 200 water molecules,” Dr Schroeder said. “It’s a huge amount of water.”

The water saving strategy does not work for all plants,and the problem is how well they detect carbon dioxide. Plants with sensitive sensors can save water. But other plants with weaker carbon dioxide receptors are not able to detect the increased levels as well and miss the opportunity to conserve water,Dr Schroeder said.

His laboratory found that by adding extra copies of the receptor proteins,called carbonic anhydrases,pores tightened,water efficiency increased and the plants still got enough carbon dioxide. Dr Schroeder said genetically manipulating certain plants could provide farmers with more efficient crops.

Wolf Frommer,a Stanford biologist,said “With increasing global warming,at least we are able to provide potential solutions.” There is one problem,though,with helping plants conserve water. When plants release moisture through their pores,it cools their leaves,in the same way sweating cools humans. This prevents them from drying out,particularly in desert regions.

There is one problem,though,with helping plants conserve water. When plants release moisture through their pores,it cools their leaves,in the same way sweating cools humans. This prevents them from drying out,particularly in desert regions.

But Dr Frommer explained that bioengineering was a slow tweaking process. He said there might be another yet undiscovered gene that when manipulated could prompt a plant to open pores when its leaves were dry. “We have to think less in terms of turning one gene up or down,but have an integrated solution,” he said. “It’s what evolution has been doing for billions of years. We have to do it faster to feed an increasing population.”