Nogues S, Allen DJ, Morison JI, Baker NR
Department of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom.
Plant Physiol. 1998 May;117(1):173-81. doi: 10.1104/pp.117.1.173.
The effects of ultraviolet-B (UV-B) radiation on water relations, leaf development, and gas-exchange characteristics in pea (Pisum sativum L. cv Meteor) plants subjected to drought were investigated. Plants grown throughout their development under a high irradiance of UV-B radiation (0.63 W m-2) were compared with those grown without UV-B radiation, and after 12 d one-half of the plants were subjected to 24 d of drought that resulted in mild water stress. UV-B radiation resulted in a decrease of adaxial stomatal conductance by approximately 65%, increasing stomatal limitation of CO2 uptake by 10 to 15%. However, there was no loss of mesophyll light-saturated photosynthetic activity. Growth in UV-B radiation resulted in large reductions of leaf area and plant biomass, which were associated with a decline in leaf cell numbers and cell division. UV-B radiation also inhibited epidermal cell expansion of the exposed surface of leaves. There was an interaction between UV-B radiation and drought treatments: UV-B radiation both delayed and reduced the severity of drought stress through reductions in plant water-loss rates, stomatal conductance, and leaf area.
研究了紫外线B（UV-B）辐射对遭受干旱的豌豆（Pisum sativum L. cv Meteor）植株水分关系、叶片发育和气体交换特性的影响。将在高UV-B辐射（0.63 W m-2）下整个发育过程中生长的植株与未接受UV-B辐射的植株进行比较，12天后，将一半植株进行24天的干旱处理，导致轻度水分胁迫。UV-B辐射使近轴气孔导度降低约65%，使CO2吸收的气孔限制增加10%至15%。然而，叶肉光饱和光合活性没有损失。UV-B辐射下的生长导致叶面积和植株生物量大幅减少，这与叶细胞数量和细胞分裂的下降有关。UV-B辐射还抑制了叶片暴露表面的表皮细胞扩展。UV-B辐射和干旱处理之间存在相互作用：UV-B辐射通过降低植株失水率、气孔导度和叶面积，既延迟了干旱胁迫，又降低了其严重程度。
