陆生植物对UV-B辐射增量响应研究进展

大气同温层的臭氧层逐渐被破坏导致太阳辐射中的UV—B辐射部分抵达地球表面增加，对陆生植物产生不同程度的影响,本文讨论了UV—B辐射对陆生植物在分子和器官水平的影响，植物可能通过UV—B光受体吸收低水平UV—B辐射，并通过不同信息途径转导，这包括钙、激酶和活性氧等，UV—B辐射诱致基因活性变化，并改变植物的形态和功能，暴露在UV—B辐射下大量基因表达发生变化，包括调节编码保护色素、DNA修复蛋白的基因和光合基因等．UV—B辐射引起光合作用、生长和生物量降低，极少数植物增加生物产量，整体群体生物量倾向减少．UV—B辐射对热带亚热带森林树种影响的报道甚少，目前增高UV—B辐射对生态系统的影响应得到重视．参45

A REVIEW:RESPONSE OF TERRESTRIAL PLANTS TO ENHANCED UV-B RADIATION

Gradual depletion of stratospheric ozone layer in atmosphere has lead to increase in solar UV-B radiation that reaches earth surface. The enhanced UV-B radiation would affect terrestrial plants in various extents. This review deals with the effect of UV-B radiation on terrestrial plants at molecular and organism levels. The perception of low levels of UV-B probably occurs via a UV-B photo receptor followed by different signaling pathways including calcium, kinase and reactive oxygen species. The direct UV-B radiation on plants that results in changes in form or function of plants appears to occur often through altered gene activity. Exposure of plants to UV-B radiation results in changes in expression of large number of genes. The genes indentified being regulated by UV-B encode protein involved in the biosynthesis of protective pigment, DNA repair and photosynthetic genes, etc. UV-B-mediated reductions in photosynthesis and growth. And biomass production can be decreased by elevated UV-B and very few plant species were stimulated to increase production. For the entire population a tendency toward negative effects occurred. Relatively little information exists on the effects of UV-B radiation on tropical and subtropical forest tree species. By now much attention on the ecosystem level consequences of elevated UV-B radiation needs to be paid. Ref 45