Chinese Bulletin of Botany ›› 2014, Vol. 49 ›› Issue (3): 254-261.DOI: 10.3724/SP.J.1259.2014.00254

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Isolation and Characterization of Regulators Involved in PHOT2-mediated Phototropism of Hypocotyls in Arabidopsis

Xiang Zhao, Lindan Wang, Yuanyuan Li, Qingping Zhao, Xiao Zhang*   

  1. State Key Laboratory of Cotton Biology, Key Laboratory of Plant Stress Biology, College of Life Sciences, Henan University, Kaifeng 475004, China
  • Received:2013-03-29 Revised:2013-09-02 Online:2014-05-01 Published:2014-06-03
  • Contact: Xiao Zhang

Abstract: Previous research suggested that phototropins (PHOT1 and PHOT2) contribute redundantly to high-intensity blue light (HBL)-induced phototropic curvature of hypocotyls in Arabidopsis thaliana, which restricts our understanding of the mechanism of PHOT2 signal transduction. We used the phot1 mutant of A. thaliana with an ethylmethane sulphonate mutation to screen HBL-insensitive mutants, avoiding the disruption of PHOT1 activity, and successfully isolated the mutant p2sa1 (phototropin2 signaling associated1). Genetic analysis revealed that the mutant is controlled by a single recessive nuclear gene. Compared with phot1, the phot1p2sa1 mutant lost phototropism on irradiation with 100 μmol·m–2·s–1 unilateral blue light, which was consistent with phot1phot2. However, phot1p2sa1 showed chloroplast avoidance of HBL, which was not consistent with phot1phot2. P2SA1 may be located downstream of PHOT2 and involved in the regulation of the hypocotyl bending response to HBL.