( A signaling pathway required for plants...)Trio of plant genes prevent 'too many mouths'

"It's surprising that size and stomata patterning ?both key to plants being able to survive on dry land ?are using the same signaling components," says Jessica McAbee, a University of Washington research associate in biology. She's one co-author of a report in the July 8 issue of Science about work with Arabidopsis, a weed-like member of the crucifer family for which scientists already have a genomic map.

Stomata are microscopic pores on the surface of plants that open to allow plants to take in carbon dioxide from the air for photosynthesis. They close when there is the danger that the plant tissue may lose too much moisture.

"Specialized cells open and close the stomata, much like opening and closing a mouth," says Keiko Torii, UW assistant professor of biology. Stomata too close together can't operate effectively.

Understanding the mechanisms that control stomata patterning offers insights into such questions as how plants evolved to protect themselves when they moved from water to land, Torii says. Even atmospheric scientists are interested in such basic plant biology, given the enormous amount of the greenhouse gas carbon dioxide taken up by the Earth's plants.

Scientists already believed that part of the signaling pathway for stomata production included the receptor-like protein Too Many Mouths, so called because when absent the plant makes too many stomata, or mouths.

Scientists were searching for a single stomata gene that had to be working in concert with Too Many Mouths to get an efficient distribution of stomata, Torii says. No one was considering that more than one gene could be involved, much less three, or that the genes could be serving other purposes, she says.

The UW team of four female scientists se
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Source:University of Washington