植物UV-B生理效应的分子机制研究进展

中波紫外线UV-B（280～320nm）是植物必需的太阳光线的组成部分，具有明显的双重效应：一方面UV-B在强度较高时，就触发产生大量活性氧对DNA、蛋白质以及生物膜等造成伤害，同时植物通过抗氧化系统对其作出防御反应以减轻伤害；另一方面，低强度的UV-B是植物生长发育的光信号因子之一，经由UVR8等光受体介导中、低、极低强度的UV-B信号，可能通过几个分子途径控制相关基因的表达，分别对植物的UV-B保护基因表达、形态建成、昼夜节律、生长发育等进行调控。目前对UVR8介导的低强度UV-B信号转导的分子机制研究相对深入。在本文中，将对UV-B生理效应分子机制的最新研究进展作一个比较全面的介绍。

Progress of Molecular Mechanisms of Plant UV-B Physiological Effects

UV-B （280-320 nm） is the essential component of the sun light, and it has dual effects on plants. On the one hand, when the UV-B radiation at higher fluence, it can act as stress factor to produce harmful reactive oxygen species. Plants can respond to this stress by antioxidant system to alleviate its damage through defense pathways. On the other hand, lower fluence UV-B can act as plant development regulator, which could play an important role in plant photomorphogenesis, expressions of protective genes, circadian rhythm, growth and development through several specific molecular pathways. These pathways mediated the signal of medium, low and very low fluence UV-B through UV-B specific receptor（s）, such as UVR8 （UV RESISTANCE LOCUS 8）, respectively. The knowledge of UVR8 mediated low fluence UV-B molecular pathway was relatively richer than others at this moment. In this review, the progress of molecular mechanisms of UV-B physiological effects are discussed in detail.