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Abscisic acid mediates barley rhizosheath formation under mild soil drying by promoting root hair growth and auxin response
Author(s) -
Zhang Yingjiao,
Xu Feiyun,
Ding Yexin,
Du Huan,
Zhang Qian,
Dang Xiaolin,
Cao Yiying,
Dodd Ian C.,
Xu Weifeng
Publication year - 2021
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/pce.14036
Subject(s) - abscisic acid , root hair , auxin , elongation , fluridone , hordeum vulgare , plant physiology , chemistry , biology , botany , microbiology and biotechnology , biochemistry , poaceae , gene , materials science , metallurgy , ultimate tensile strength
Soil drying enhances root ABA accumulation and rhizosheath formation, but whether ABA mediates rhizosheath formation is unclear. Here, we used the ABA‐deficient mutant Az34 to investigate molecular and morphological changes by which ABA could affect rhizosheath formation. Mild soil drying with intermittent watering increased rhizosheath formation by promoting root and root hair elongation. Attenuated root ABA accumulation in Az34 barley constrained the promotion of root length and root hair length by drying soil, such that Az34 had a smaller rhizosheath. Pharmacological experiments of adding fluridone (an ABA biosynthesis inhibitor) and ABA to drying soil restricted and enhanced rhizosheath formation respectively in Az34 and wild‐type Steptoe barley. RNA sequencing suggested that ABA accumulation mediates auxin synthesis and responses and root and root hair elongation in drying soil. In addition, adding indole‐3‐acetic acid (IAA) to drying soil increased rhizosheath formation by promoting root and root hair elongation in Steptoe and Az34 barley. Together, these results show that ABA accumulation induced by mild soil drying enhance barley rhizosheath formation, which may be achieved through promoting auxin response.