Nogues S, Allen DJ, Morison JI, Baker NR
Department of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom.
Plant Physiol. 1999 Oct;121(2):489-96. doi: 10.1104/pp.121.2.489.
The effects of ultraviolet-B (UV-B) radiation on stomatal conductance (g(s)) in pea (Pisum sativum L.), commelina (Commelina communis L.), and oilseed rape (Brassica napus L.) plants were investigated. Plants were grown in a greenhouse either with three different high ratios of UV-B to photosynthetically active radiation or with no UV-B radiation. Pea plants grown in the highest UV-B radiation (0.63 W m(-2)) exhibited a substantial decrease of adaxial and abaxial g(s) (approximately 80% and 40%, respectively). With growth in 0.30 W m(-2) of UV-B adaxial g(s) was decreased by 23%, with no effect on abaxial g(s), and lower UV-B irradiance of 0.21 W m(-2) had no effect on either surface. Although abaxial g(s) increased when leaves were turned over in control plants, it did not in plants grown with the highest UV-B. Adaxial g(s) in commelina and oilseed rape also decreased on exposure to high UV-B (0.63 W m(-2)). For previously unexposed pea plants the time course of the effect of UV-B on g(s) was slow, with a lag of approximately 4 h, and a time constant of approximately 3 h. We conclude that there is a direct effect of UV-B on stomata in addition to that caused by changes in mesophyll photosynthesis.
研究了紫外线 - B（UV - B）辐射对豌豆（Pisum sativum L.）、鸭跖草（Commelina communis L.）和油菜（Brassica napus L.）植株气孔导度（g(s)）的影响。将植株种植在温室中，设置三种不同的高UV - B与光合有效辐射比，或者不进行UV - B辐射。生长在最高UV - B辐射（0.63 W m(-2)）下的豌豆植株，其近轴面和远轴面的g(s)显著降低（分别约为80%和40%）。在0.30 W m(-2)的UV - B辐射下生长时，近轴面g(s)降低了23%，对远轴面g(s)无影响，而较低的0.21 W m(-2) UV - B辐照度对两个表面均无影响。尽管对照植株叶片翻转时远轴面g(s)增加，但在最高UV - B辐射下生长的植株中并非如此。暴露于高UV - B（0.63 W m(-2)）时，鸭跖草和油菜的近轴面g(s)也降低。对于之前未暴露于UV - B的豌豆植株，UV - B对g(s)的影响时间进程缓慢，滞后约4小时，时间常数约为3小时。我们得出结论，除了叶肉光合作用变化所引起的影响外，UV - B对气孔有直接影响。
