Phototropins mediate blue and red light-induced chloroplast movements in Physcomitrella patens
Phototropins mediate blue and red light-induced chloroplast movements in Physcomitrella patens
复制标题
DOI：
10.1104/pp.104.042705
复制
发表时间：
2004-07-01
期刊：
影响因子：
7.4
通讯作者：
Wada, M
中科院分区：
文献类型：
--
作者：
Kasahara, M;Kagawa, T;Wada, M
拟南芥的致光素是一种蓝光受体，介导向光性、叶绿体运动和气孔打开。蓝光和红光诱导小立藓叶绿体运动。为了研究植物叶绿体运动的光感受器，通过筛选cDNA文库，分离出4个趋光素基因PHOTA1、PHOTA2、PHOTB1和PHOTB2。根据推测的氨基酸序列，将这些基因分为PHOTA和PHOTB两类。然后通过同源重组生成促光蛋白干扰物，并用于叶绿体运动分析。结果表明，蓝光诱导的叶绿体运动是由趋光素介导的。正如报道的那样，photA和photB组都能介导叶绿体回避，尽管photA组对这一反应的贡献更大。在phota2phot1photb2三重干扰中，红光诱导的叶绿体运动也显著减少。由于光敏色素是植物叶绿体运动的主要光感受器，因此趋光素可能是光敏色素信号通路中的下游组分。据我们所知，这项工作首次展示了促光素蓝紧受体对它不吸收的波长作出反应的功能。
Phototropin is the blue-light receptor that mediates phototropism, chloroplast movement, and stomatal opening in Arabidopsis. Blue and red light induce chloroplast movement in the moss Physcomitrella patens. To study the photoreceptors for chloroplast movement in P. patens, four phototropin genes (PHOTA1, PHOTA2, PHOTB1, and PHOTB2) were isolated by screening cDNA libraries. These genes were classified into two groups (PHOTA and PHOTB) on the basis of their deduced amino acid sequences. Then phototropin disruptants were generated by homologous recombination and used for analysis of chloroplast movement. Data revealed that blue light-induced chloroplast movement was mediated by phototropins in P. patens. Both photA and photB groups were able to mediate chloroplast avoidance, as has been reported for Arabidopsis phot2, although the photA group contributed more to the response. Red light-induced chloroplast movement was also significantly reduced in photA2photB1photB2 triple disruptants. Because the primary photoreceptor for red light-induced chloroplast movement in P. patens is phytochrome, phototropins may be downstream components of phytochromes in the signaling pathway. To our knowledge, this work is the first to show a function for the phototropin blue-tight receptor in a response to wavelengths that it does not absorb.