Stomatal function

Apple ME, Olszyk DM, Lewis J, Southworth D, Tingey DT (2000) Morphology and stomatal function of Douglas fir needles exposed to climate change elevated C02 and temperature. Int J Plant Sd 161 127-132... 

During the late afternoon when the vapor pressure gradient declines, ponderosa pine stomata may open wider, resulting in greater oxidant uptake and simultaneous depression of carbon dioxide fixation. Some knowledge of stomatal function would be useful to see if there is any relationship between intraspecific oxidant tolerance and ability to close stomates in the presence of elevated ozone concentrations. This mechanism is an inherited characteristic of an ozone-resistant onion variety which closes its stomates when exposed to ozone (30). It is not known if this mechanism is involved in conditioning interspecific tolerance or sensitivity of the important conifer species. 

Cowan, I.R., and Farquhar, G.D. 1977. Stomatal function in relation to leaf metabolism and environment. In Jennings, D.H. (Ed.). Integration of Activity in the Higher Plant. Cambridge University Press, Cambridge, UK, pp. 471—505. 

Finnigan, J.J., Raupach, M.R. (1987) Transfer processes in plant canopies in relation to stomatal characteristics, in, Stomatal Function, (eds. E. Zeiger, Farquar,G.D and Cowan I.R.), Stanford University Press, Stanford, California, 385-429. 

Much of our understanding of transporters in guard cells has come from efforts to dissect the effects of hormones on stomatal function. Arguably the largest contribution has come from the study of ABA-induced stomatal closure. Classically, ABA has also received the most attention as a phytohormone regulator of stomatal apertures (see review by Raschke... 

Critical loads to forest soils have been proposed for the deposition of total nitrogen, total sulfur, and total acidity. Critical loads models assume that indirect effects occur on trees via changes in soil chemistry. However, there exist important direct and indirect impacts of wet and dry deposition on leaves and needles with regard to photosynthesis, nutrient leaching, stomatal function, and leaf surface properties. The values for critical loads are influenced by precipitation, elevation, soil texture, and base cation deposition. 

Low molecular weight toxins from Fusiococcum amygdali (75) and Helminthosporium maydis (76) are known to affect stomatal function through their action on guard cells but no polymeric toxins have been shown to act at this site. 

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