《植物生理学报》 2011, 47(9): 855-860

植物下胚轴向光弯曲机制研究进展

乔新荣, 赵翔, 张骁*

河南大学生命科学学院, 棉花生物学国家重点实验室/植物逆境生物学教育部重点实验室, 河南开封475004

通信作者：张骁；E-mail: xzhang@henu.edu.cn；Tel: 0378-3880008

摘　要：

植物向光弯曲生长主要是由于其向光和背光面生长素的不对称分布引起。近年来研究发现, 在不同强度的蓝光单侧 照射下, 植物可能存在不同的向光弯曲调节机制。目前, 关于向光素PHOT1介导弱蓝光引起的下胚轴弯曲研究较为详细, 即PHOT1感受蓝光后, 与其下游的信号蛋白NPH3、RPT2和PKS1相互作用, 调控生长素运输蛋白的活性及定位, 诱导生长 素的不对称分布引起向光弯曲。PHOT1和PHOT2以功能冗余方式调节强蓝光引起的植物下胚轴向光弯曲, NPH3可能作为 共享调节因子, 引发不同的信号转导通路实现功能互补。此外, 其他光受体、激素、蛋白激酶、蛋白磷酸酶以及Ca2+也参 与了植物向光弯曲的调节。本文就近年来有关植物下胚轴向光弯曲信号组分及可能的网络关系进行总结, 并对该研究领 域存在的问题及今后可能的研究方向进行展望。

关键词：向光素; 向光弯曲; 信号转导

收稿：2011-07-27   修定：2011-09-02

资助：国家自然科学基金(30871300)和河南省教育厅自然科学基金项目(2011B180007)。

Research Advances in Plant Hypocotyl Phototropism

QIAO Xin-Rong, ZHAO Xiang, ZHANG Xiao*

State Key Laboratory of Cotton Biology, Key Laboratory of Plant Stress Biology, Ministry of Education, College of Life Sciences, Henan University, Kaifeng, Henan 475004, China

Corresponding author: ZHANG Xiao; E-mail: xzhang@henu.edu.cn; Tel: 0378-3880008

Abstract:

The bending of the seedling stem toward unilateral light is caused by asymmetrical auxin distribution between the shaded and illuminated sides of plant organs. In recent years, genetic analysis has shown that plant may have different mechanisms in response to different light intensities in phototropism. In weak blue light, blue light receptors phototropin1 (PHOT1) regulates phototropism by directly interacting with signaling proteins NPH3, RPT2 and PKS1, resulting in asymmetrical distribution of auxin. In strong blue light, PHOT1 and PHOT2 contribute redundantly to blue-light-induced phototropic curvature of hypocotyls. The NPH3 may act as a common factor in different signaling pathways to complement functions. In addition, other photoreceptors, such as hormones, protein phosphatase and Ca²⁺, are also involved in phototropic response. This paper summarized some signaling components and their possible relationship in phototropism, and the problems remained are discussed, finally the possible research directions in this field are proposed.

Key words: phototropin; phototropism; signal transduction