In the past few years great progress has been made in identifying and characterizing plant photoreceptors active in the blue/UV-A regions of the spectrum. These photoreceptors include cryptochrome 1 and cryptochrome 2, which are similar in structure and chromophore composition to the prokaryotic DNA photolyases. However, they have a C-terminal extension that is not present in photolyases and lack photolyase activity. They are involved in regulation of cell elongation and in many other processes, including interfacing with circadian rhythms and activating gene transcription. Animal cryptochromes that play a photoreceptor role in circadian rhythms have also been characterized. Phototropin, the protein product of the NPH1 gene in Arabidopsis, likely serves as the photoreceptor for phototropism and appears to have no other role. A plasma membrane protein, it serves as photoreceptor, kinase, and substrate for light-activated phosphorylation. The carotenoid zeaxanthin may serve as the chromophore for a photoreceptor involved in blue-light-activated stomatal opening. The properties of these photoreceptors and some of the downstream events they are known to activate are discussed.

中文翻译：

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高等植物中的蓝光感光体。

在过去的几年中，在鉴定和表征在光谱的蓝色/ UV-A区域中有活性的植物感光器方面取得了巨大进展。这些感光体包括隐花色素1和隐花色素2，其结构和生色团组成与原核DNA光解酶相似。但是，它们具有的C端延伸区域不存在于光解酶中，并且缺乏光解酶活性。它们参与细胞伸长的调控以及许多其他过程，包括与昼夜节律的交互作用和激活基因转录。在昼夜节律中起感光作用的动物隐色色素也已被鉴定。拟南芥中NPH1基因的蛋白质产物光养蛋白很可能充当光养性的光感受器，并且似乎没有其他作用。质膜蛋白，充当光感受器，激酶和光激活磷酸化的底物。类胡萝卜素玉米黄质可以用作参与蓝光激活气孔开口的感光体的发色团。讨论了这些感光体的特性以及已知会激活的一些下游事件。