Mizuno Takeshi, Oka Haruka, Yoshimura Fumi, Ishida Kai, Yamashino Takafumi
a Laboratory of Molecular and Functional Genomics , School of Agriculture, Nagoya University , Nagoya , Japan.
Biosci Biotechnol Biochem. 2015;79(12):1987-94. doi: 10.1080/09168451.2015.1065171. Epub 2015 Jul 20.
Shade avoidance responses are changes in plant architecture to reduce the part of a body that is in the shade in natural habitats. The most common warning signal that induces shade avoidance responses is reduction of red/far-red light ratio perceived by phytochromes. A pair of basic helix-loop-helix transcription factors, named PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) and PIF5, is crucially involved in the shade avoidance-induced hypocotyl elongation in Arabidopsis thaliana. It has been recently reported that PIF7 also plays a role in this event. Here, we examined the involvement of these PIFs in end-of-day far-red light (EODFR) responses under light and dark cycle conditions. It was shown that PIF7 played a predominant role in the EODFR-dependent hypocotyl elongation. We propose the mechanism by which PIF7 together with PIF4 and PIF5 coordinately transcribes a set of downstream genes to promote elongation of hypocotyls in response to the EODFR treatment.
避荫反应是植物形态结构的变化，目的是在自然生境中减少植物处于荫蔽中的部分。诱导避荫反应最常见的警示信号是光敏色素感知到的红光/远红光比例降低。一对名为光敏色素互作因子4（PIF4）和PIF5的碱性螺旋-环-螺旋转录因子，在拟南芥避荫诱导的下胚轴伸长过程中起着关键作用。最近有报道称，PIF7在这一过程中也发挥作用。在此，我们研究了这些PIF在光暗循环条件下的日终远红光（EODFR）反应中的作用。结果表明，PIF7在EODFR依赖的下胚轴伸长中起主要作用。我们提出了一种机制，即PIF7与PIF4和PIF5协同转录一组下游基因，以促进下胚轴响应EODFR处理而伸长。
