Genetic controls for stomata density and spatial arrangement

Photo credit: Dept. Biol. Univ. Washington

Wild type stomata in Arabidopsis

Challenging a Fine Balance

By Kristy Brady

EXCERPT

No-stomata mutant in Arabidopsis – http://www.biology.washington.edu/newsletter/sum12/images/spch_round%20copy.jpg

Stomata are tightly regulated in both function and development. If there are too many, or they are open for too much of the time, a plant loses too much water resulting in dessication. Too few, or if they are not open enough, too little CO2 enters the plant, preventing photosynthesis. It’s a critical balance with implications not only for all plant life, but the atmosphere and biosphere, as well. Endowed Distinguished Biology professor and Howard Hughes Medical Institute and Gordon and Betty Moore Foundation Investigator Keiko Torii, is one of the leading researchers on the genetic control of stomatal patterning.

Stomata-only mutant in Arabidopsis – http://www.biology.washington.edu/newsletter/sum12/images/scrm-D_round%20copy.jpg

Ten years ago very little was understood about plant stomatal development. Plant biologists had better understanding of the mechanism by which stomata functioned, that is, how guard
cells swelled and deflated to open or close the epidermal pore. But how stomata formed, and how they were arranged across a leaf’s surface, were still unsolved mysteries.

Torii’s own research in this area transpired serendipitously. She was studying a group of receptor kinases, a type of enzymes sensing external signals and transducing the signals inside of the cells via phosphorylation, when a knock-out experiment yielded some interesting stomatal patterning
mutants. The mutants piqued Torii’s interest and she hasn’t looked back since. Additional
knock-out experiments identified additional players in the system, including several key
transcription factors that direct the cells to become stomata. Importantly, elements of the genetic
control of stomatal patterning that Torii has identified using the model plant Arabidopsis appear
to be highly conserved across all land plants.

This raises an interesting question: could stomatal patterning be manipulated for agricultural
purposes?

Read the full article: Department of Biology – University of Washington