title: The ABA receptor PYL8 promotes lateral root growth by enhancing MYB77-dependent transcription of auxin-responsive genes.
abstract: The phytohormone abscisic acid (ABA) regulates plant growth, development, and abiotic stress responses. ABA signaling is mediated by a group of receptors known as the PYR1/PYL/RCAR family, which includes the pyrabactin resistance 1-like protein PYL8. Under stress conditions, ABA signaling activates SnRK2 protein kinases to inhibit lateral root growth after emergence from the primary root. However, even in the case of persistent stress, lateral root growth eventually recovers from inhibition. We showed that PYL8 is required for the recovery of lateral root growth, following inhibition by ABA. PYL8 directly interacted with the transcription factors MYB77, MYB44, and MYB73. The interaction of PYL8 and MYB77 increased the binding of MYB77 to its target MBSI motif in the promoters of multiple auxin-responsive genes. Compared to wild-type seedlings, the lateral root growth of pyl8 mutant seedlings and myb77 mutant seedlings was more sensitive to inhibition by ABA. The recovery of lateral root growth was delayed in pyl8 mutant seedlings in the presence of ABA, and the defect was rescued by exposing pyl8 mutant seedlings to the auxin IAA (3-indoleacetic acid). Thus, PYL8 promotes lateral root growth independently of the core ABA-SnRK2 signaling pathway by enhancing the activities of MYB77 and its paralogs, MYB44 and MYB73, to augment auxin signaling.
authors.affiliation: Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.|School of Life Sciences, University of Science and Technology of China, Hefei 230026, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Xing
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Xingang
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Yueh-Ju
authors.initials: YJ
authors.lastname: Hou
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.|College of Animal Science and Technology, Northwest A&F University, Yangling, Shaan'xi 712100, China.
authors.forename: Jinghui
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Cheng-Guo
authors.initials: CG
authors.lastname: Duan
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Shanghai Center for Plant Stress Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA.
authors.forename: Jian-Kang
authors.initials: JK
authors.lastname: Zhu
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism; D017360:Arabidopsis / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology*; D007210:Indoleacetic Acids / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development* / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology*; D013312:Stress, Physiological / Q000502:physiology; D014157:Transcription Factors / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; C529221:At5g67300 protein, Arabidopsis; C587572:Myb73 protein, Arabidopsis; C525048:Myb77 protein, Arabidopsis; C582322:PYL8 protein, Arabidopsis; D014157:Transcription Factors; C030737:indoleacetic acid; D000040:Abscisic Acid