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Abscisic acid accumulation modulates auxin transport in the root tip to enhance proton secretion for maintaining root growth under moderate water stress
Author(s) -
Xu Weifeng,
Jia Liguo,
Shi Weiming,
Liang Jiansheng,
Zhou Feng,
Li Qianfeng,
Zhang Jianhua
Publication year - 2013
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.12004
Subject(s) - auxin , elongation , abscisic acid , root hair , secretion , lateral root , proton transport , water transport , biophysics , chemistry , arabidopsis , botany , biology , microbiology and biotechnology , water flow , membrane , biochemistry , materials science , mutant , environmental engineering , gene , engineering , metallurgy , ultimate tensile strength
Summary 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 + ‐ ATP ase 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 + ‐ ATP ase 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.