Two homologous INDOLE-3-ACETAIVHDE (IAM) HYDROLASE genes are required for the auxin effects of IAM in Arabidopsis  

作　　者：Yangbin Gao Xinhua Dai Yuki Aoi Yumiko Takebayashi Liping Yang Xiaorui Guo Qiwei Zeng Hanchuanzhi Yu Hiroyuki Kasahara Yunde Zhao 

机构地区：[1]Section of Cell and Developmental Biology,University of California San Diego,La Jolla,CA,92093-0116,USA [2]RIKEN Center for Sustainable Resource Science,Kanagawa,230-0045,Japan [3]School of Life Sciences,Jilin Normal University,Siping,136000,China [4]Key Laboratory of Plant Ecology,Northeast Forestry University,Harbin,150040,China [5]State Key Laboratory of Silkworm Genome Biology,Institute of Sericulture and Systems Biology,Southwest University,Chongqing,400716,China [6]Institute of Global Innovation Research,Tokyo University of Agriculture and Technology,Tokyo,183-8509,Japan [7]Department of Bioregulation and Biointeraction,Graduate School of Agriculture,Tokyo University of Agriculture and Technology,Fuchu,183-8509,Japan

出　　处：《Journal of Genetics and Genomics》2020年第3期157-165,共9页遗传学报（英文版）

基　　金：supported by the NIH grant R01GM114660 to Y.Z。

摘　　要：Indole-3-acetamide(IAM)is the first confirmed auxin biosynthetic intermediate in some plant pathogenic bacteria.Exogenously applied IAM or production of IAM by overexpressing the bacterial iaaM gene in Arabidopsis causes auxin overproduction phenotypes.However,it is still inconclusive whether plants use IAM as a key precursor for auxin biosynthesis.Herein,we reported the isolation IAM HYDROLASE 1(IAMH1)gene in Arabidopsis from a forward genetic screen for IAM-insensitive mutants that display normal auxin sensitivities.IAMH1 has a close homolog named IAMH2 that is located right next to IAMH1on chromosomeⅣin Arabidopsis.We generated iamh1 iamh2 double mutants using our CRISPR/Cas9gene editing technology.We showed that disruption of the IAMH genes rendered Arabidopsis plants resistant to IAM treatments and also suppressed the iaaM overexpression phenotypes,suggesting that IAMH1 and IAMH2 are the main enzymes responsible for converting IAM into indole-3-acetic acid(IAA)in Arabidopsis.The iamh double mutants did not display obvious developmental defects,indicating that IAM does not play a major role in auxin biosynthesis under normal growth conditions.Our findings provide a solid foundation for clarifying the roles of IAM in auxin biosynthesis and plant development.

关 键 词：AUXIN Auxin biosynthesis Indole-3-acetamide ARABIDOPSIS CRISPR IAMH1 IAMH2 

分 类 号：Q943.2[生物学—植物学]