title: OsCYP2, a chaperone involved in degradation of auxin-responsive proteins, plays crucial roles in rice lateral root initiation.
abstract: Auxin plays a pivotal role in many facets of plant development. It acts by inducing the interaction between auxin-responsive [auxin (AUX)/indole-3-acetic acid (IAA)] proteins and the ubiquitin protein ligase SCF(TIR) to promote the degradation of the AUX/IAA proteins. Other cofactors and chaperones that participate in auxin signaling remain to be identified. Here, we characterized rice (Oryza sativa) plants with mutations in a cyclophilin gene (OsCYP2). cyp2 mutants showed defects in auxin responses and exhibited a variety of auxin-related growth defects in the root. In cyp2 mutants, lateral root initiation was blocked after nuclear migration but before the first anticlinal division of the pericycle cell. Yeast two-hybrid and in vitro pull-down results revealed an association between OsCYP2 and the co-chaperone Suppressor of G2 allele of skp1 (OsSGT1). Luciferase complementation imaging assays further supported this interaction. Similar to previous findings in an Arabidopsis thaliana SGT1 mutant (atsgt1b), degradation of AUX/IAA proteins was retarded in cyp2 mutants treated with exogenous 1-naphthylacetic acid. Our results suggest that OsCYP2 participates in auxin signal transduction by interacting with OsSGT1.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, Hangzhou, 310058, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Kang
authors.forename: Zhongchen
authors.initials: Z
authors.lastname: Zhang
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.forename: Libin
authors.initials: L
authors.lastname: Zheng
authors.forename: Weihua
authors.initials: W
authors.lastname: Mao
authors.forename: Meifei
authors.initials: M
authors.lastname: Li
authors.forename: Yunrong
authors.initials: Y
authors.lastname: Wu
authors.forename: Ping
authors.initials: P
authors.lastname: Wu
authors.forename: Xiaorong
authors.initials: X
authors.lastname: Mo
mesh_terms: D003001:Cloning, Molecular; D021983:Cyclophilins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009154:Mutation; D012275:Oryza / Q000235:genetics* / Q000254:growth & development; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development*; D015398:Signal Transduction; D020798:Two-Hybrid System Techniques
chemical_list: D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D010940:Plant Proteins; C030737:indoleacetic acid; D021983:Cyclophilins