光受体UVR8对UV-B响应机制研究进展

来自太阳光谱中的UV-B辐射被认为是一种重要的环境信号,可以被植物感受并诱导植物调整自身生长和发育状态以适应环境。人们对植物中光敏色素、隐花色素和蓝光受体向光素的研究已非常深入,但对植物响应UV-B的机制仅在最近才取得一些突破性进展。这些研究发现,植物中存在着UV-B受体UVR8(UV Resistance Locus 8)。目前认为,UVR8二聚体感应UV-B后瞬间解聚为单体,并与E3泛素连接酶COP1(constitutively photomorphogenic 1)相互作用,从而激活UV-B响应基因的表达。该文从UVR8的发现、UVR8的结构和感受UV-B机制、UVR8二聚体重新形成以及UV-B信号传导与可见光信号传导途径间的差异等方面综述了关于UV-B受体UVR8的最新研究成果。

Mechanism of UV-B Perception by the UVR8 Photoreceptor

Ultraviolet-B(UV-B) radiation is a key environmental signal that is specifically perceived by plants to promote UV acclimation and survival in sunlight.In contrast to phytochrome-,cryptochrome- and phototropin-sensing systems,with considerable knowledge accumulated,the UV-B photoreceptor UV Resistance locus 8 (UVR8) was only recently described at the molecular level.UV-B perception was thought to induce dissociation of the UVR8 homodimer,allowing its subsequent interaction with Constitutively Photomorphogenic 1(COP1) and activation of UV-B responsive genes.Here,we review the recent studies of the UVR8 photoreceptor in the context of UVR8 discovery,UVR8 structure,UV-B perception mechanism,UVR8 redimerization and the commonalities and differences between UV-B and visible light signaling.