title: Modulation of auxin content in Arabidopsis confers improved drought stress resistance.
abstract: Auxin is a well-known plant phytohormone that is involved in multiple plant growth processes and stress responses. In this study, auxin response was significantly modulated under drought stress condition. The iaaM-OX transgenic lines with higher endogenous indole-3-acetic acid (IAA) level and IAA pre-treated wild type (WT) plants exhibited enhanced drought stress resistance, while the yuc1yuc2yuc6 triple mutants with lower endogenous IAA level showed decreased stress resistance in comparison to non-treated WT plants. Additionally, endogenous and exogenous auxin positively modulated the expression levels of multiple abiotic stress-related genes (RAB18, RD22, RD29A, RD29B, DREB2A, and DREB2B), and positively affected reactive oxygen species (ROS) metabolism and underlying antioxidant enzyme activities. Moreover, auxin significantly modulated some carbon metabolites including amino acids, organic acids, sugars, sugar alcohols and aromatic amines. Notably, endogenous and exogenous auxin positively modulated root architecture especially the lateral root number. Taken together, this study demonstrated that auxin might participate in the positive regulation of drought stress resistance, through regulation of root architecture, ABA-responsive genes expression, ROS metabolism, and metabolic homeostasis, at least partially.
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Shi
authors.affiliation: College of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China; University of Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Tiantian
authors.initials: T
authors.lastname: Ye
authors.affiliation: College of Agronomy, Xinjiang Agricultural University, Urumqi, Xinjiang 830052, China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Liu
authors.affiliation: College of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
authors.forename: Kejian
authors.initials: K
authors.lastname: Ding
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China. Electronic address: zhulongch@wbgcas.cn.
authors.forename: Zhulong
authors.initials: Z
authors.lastname: Chan
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D055864:Droughts; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D017382:Reactive Oxygen Species
keywords: Abscisic acid; Arabidopsis; Auxin; Drought stress; Metabolite; Reactive oxygen species