title: Abscisic acid accumulation modulates auxin transport in the root tip to enhance proton secretion for maintaining root growth under moderate water stress.
abstract: Maintenance of root growth is essential for plant adaptation to soil drying. Here, we tested the hypothesis that auxin transport is involved in mediating ABA's modulation by activating proton secretion in the root tip to maintain root growth under moderate water stress. Rice and Arabidopsis plants were raised under a hydroponic system and subjected to moderate water stress (-0.47 MPa) with polyethylene glycol (PEG). ABA accumulation, auxin transport and plasma membrane H(+)-ATPase activity at the root tip were monitored in addition to the primary root elongation and root hair density. We found that moderate water stress increases ABA accumulation and auxin transport in the root apex. Additionally, ABA modulation is involved in the regulation of auxin transport in the root tip. The transported auxin activates the plasma membrane H(+)-ATPase to release more protons along the root tip in its adaption to moderate water stress. The proton secretion in the root tip is essential in maintaining or promoting primary root elongation and root hair development under moderate water stress. These results suggest that ABA accumulation modulates auxin transport in the root tip, which enhances proton secretion for maintaining root growth under moderate water stress.
authors.affiliation: School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, Hong Kong.|State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
authors.forename: Weifeng
authors.initials: W
authors.lastname: Xu
authors.affiliation: School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, Hong Kong.|College of Agronomy, Inner Mongolia Agricultural University, Huhhot, China.
authors.forename: Liguo
authors.initials: L
authors.lastname: Jia
authors.affiliation: State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
authors.forename: Weiming
authors.initials: W
authors.lastname: Shi
authors.affiliation: College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, China.
authors.forename: Jiansheng
authors.initials: J
authors.lastname: Liang
authors.affiliation: College of Life Sciences, South China Agricultural University, Guangzhou, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhou
authors.affiliation: School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, Hong Kong.
authors.forename: Qianfeng
authors.initials: Q
authors.lastname: Li
authors.affiliation: School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, Hong Kong.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism* / Q000494:pharmacology; D000222:Adaptation, Physiological; D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000201:enzymology; D003681:Dehydration / Q000378:metabolism; D004789:Enzyme Activation; D057075:Enzyme Assays; D018527:Hydroponics / Q000379:methods; D007210:Indoleacetic Acids / Q000032:analysis / Q000378:metabolism*; D012275:Oryza / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D011092:Polyethylene Glycols / Q000494:pharmacology; D006180:Proton-Translocating ATPases / Q000378:metabolism; D011522:Protons; D013312:Stress, Physiological; D014867:Water / Q000378:metabolism
chemical_list: D007210:Indoleacetic Acids; D011522:Protons; D014867:Water; D011092:Polyethylene Glycols; D000040:Abscisic Acid; D006180:Proton-Translocating ATPases