The expression of phototropins in Arabidopsis leaves: developmental and light regulation
The expression of phototropins in Arabidopsis leaves: developmental and light regulation
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DOI：
10.1093/jxb/ers061
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发表时间：
2012-02-01
影响因子：
6.9
通讯作者：
Gabrys, Halina
中科院分区：
文献类型：
--
作者：
Labuz, Justyna;Sztatelman, Olga;Gabrys, Halina
向光蛋白是一类蓝光受体，在植物发育过程中发挥着不同的作用。拟南芥的两种向光蛋白phot1和phot2具有很强的重叠功能。在幼苗中，两种光感受器都负责向光性。在成熟叶片中，它们冗余地调节叶片形状、气孔开度和叶绿体的积累，而向光蛋白2单独控制叶绿体回避反应。光不仅激活光致蛋白，而且影响它们的表达水平。在拟南芥幼苗中，PHOT1被下调，PHOT2被上调。由于在成熟的拟南芥叶片中的向光蛋白的转录水平的数据是稀缺的，一个全面的实时PCR研究PHOT1和PHOT2的表达在发展过程中进行，从幼苗到衰老的叶片。到目前为止，无论是光的表达，也没有光的调制过程中的衰老进行了研究。结果表明，在拟南芥的生命周期中，一般的调控模式保持保守，而转录水平随时间波动，指出光控制的重要性的向光蛋白的功能。研究的第二部分确定了光合作用信号和光受体激活的转导途径对光促素mRNA水平的影响。使用光感受器缺陷的拟南芥突变株系检查蓝光和红光的影响。这些结果揭示了一个复杂的网络，这些受体之间的相互作用，在调节向光素转录谱。隐花色素1和光敏色素B似乎是参与调节PHOT 1转录物积累的主要光受体。PHOT 2的表达依赖于隐花色素和光敏色素A。
Phototropins are blue light receptors, which play different roles during plant development. Two phototropins of Arabidopsis thaliana, phot1 and phot2, have strongly overlapping functions. In seedlings, both photoreceptors are responsible for phototropism. In mature leaves they redundantly regulate leaf shape, stomatal opening, and the accumulation of chloroplasts, whereas phototropin2 alone controls chloroplast avoidance response. Light not only activates phototropins, but also affects the level of their expression. In Arabidopsis seedlings, PHOT1 is downregulated and PHOT2 is upregulated by light. Since data on transcription levels of phototropins in mature Arabidopsis leaves is scarce, a comprehensive real-time PCR study of PHOT1 and PHOT2 expression during development was performed, from seedlings to senescing leaves. So far, neither the phototropin expression nor its modulation by light have been investigated during senescence. The results show that the general regulation pattern remains conserved during Arabidopsis lifecycle, whereas the level of transcripts fluctuates over time, pointing to the significance of the light control for functioning of phototropins. The second part of the study determined the influence of photosynthesis-derived signals and photoreceptor-activated transduction pathways on phototropin mRNA levels. The effects of blue and red light were examined using Arabidopsis mutant lines deficient in photoreceptors. The results reveal a complex network of interactions between these receptors in the regulation of phototropin transcription profiles. Cryptochrome1 and phytochromeB appear to be main photoreceptors involved in the regulation of PHOT1 transcript accumulation. The expression of PHOT2 is dependent on both cryptochromes and phytochromeA.