Gene that controls ozone resistance of plants could lead to drought-resis...( Biologists at the University of Cali...)

Biologists at the University of California, San Diego, working with collaborators at the University of Helsinki in Finland and two other European institutions, have elucidated the mechanism of a plant gene that controls the amount of atmospheric ozone entering a plants leaves.

Their finding helps explain why rising concentrations of carbon dioxide in the atmosphere may not necessarily lead to greater photosynthetic activity and carbon sequestration by plants as atmospheric ozone pollutants increase. And it provides a new tool for geneticists to design plants with an ability to resist droughts by regulating the opening and closing of their stomatathe tiny breathing pores in leaves through which gases and water vapor flow during photosynthesis and respiration.

Droughts, elevated ozone levels and other environmental stresses can impact crop yields, said Jean Chin, who oversees membrane protein grants at the National Institute of General Medical Sciences, which partially funded the research. This work gives us a clearer picture of how plants respond to these kinds of stresses and could lead to new ways to increase their resistance.

The discovery is detailed in this weeks advance online publication of the journal Nature by biologists at UCSD, University of Helsinki in Finland, University of Tartu in Estonia and the University of the West of England. Last year, the journal published another study by British researchers that found that ozone generated from the nitrogen oxides of vehicle emissions would significantly reduce the ability of plants to increase photosynthesis and store the excess carbon in the atmosphere projected from rising levels of carbon dioxide.

When ozone enters the leaf through the stomatal pores, it damages the plants photosynthetic machinery and basically causes green leaves to lose their color, a process called chlorosis, said Julian Schroeder, a professor of biological sciences at UC San Diego and one of the
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