Plant biology

Stomatal Pore Density

Science's STKE  12 Dec 2000:
Vol. 2000, Issue 62, pp. tw1
DOI: 10.1126/stke.2000.62.tw1

As atmospheric CO2 concentration increases, the density of stomatal pores on the leaf surface decreases to prevent loss of water during transpiration. An analysis of mutants by Gray et al. reveals that a gene in the plant Arabidposis thaliana called high carbon dioxide (HIC) may be responsible for regulating stomatal development in response to CO2. HIC, expressed exclusively in guard cells that flank stomatal pores, encodes a putative 3-keto acyl coenzyme A synthase, an enzyme involved in synthesizing long-chain fatty acids that comprise components of the extracellular matrix found at the surface of guard cells. When HIC expression is disrupted, plants can no longer respond to increases in CO2. The authors propose that absence of the HIC-encoded enzyme could alter the composition of the extracellular matrix and thus affect diffusion of CO2-regulated morphogens that regulate stomatal development.

Gray, J.E., Holroyd, G.H., Van der Lee, F.M., Bahrami, A.R., Sijmons, P.C., Woodward, F.I., Schuch, W., and Hetherington, A.M. (2000) The HIC signalling pathway links CO2 perception to stomatal development. Nature 408: 713-716. [Online Journal]