title: Jasmonate-activated MYC2 represses ETHYLENE INSENSITIVE3 activity to antagonize ethylene-promoted apical hook formation in Arabidopsis.
abstract: The apical hook is an essential structure that enables epigeal plants to protrude through the soil. Arabidopsis thaliana HOOKLESS1 (HLS1) is reported to be a key regulator of hook development and a direct target gene of the ethylene (ET)-activated transcription factors ETHYLENE INSENSITIVE3 (EIN3) and its close homolog EIN3-Like1. Previous research has shown that the phytohormones jasmonate (JA) and ET antagonistically regulate apical hook development, although the underlying molecular mechanism is largely unknown. Here, we report that JA represses hook formation by reducing HLS1 expression. Our results further reveal that the JA-activated transcription factor MYC2 represses EIN3 function to reduce HLS1 expression through at least the following two layers of regulation: (1) MYC2 binds to the promoter of an F-box gene, EIN3 BINDING F-BOX PROTEIN1, to induce its expression and thus promote EIN3 degradation; and (2) MYC2 physically interacts with EIN3 and inhibits its DNA binding activity. Collectively, our findings shed light on the molecular mechanism underlying the antagonism between JA and ET during apical hook development and provide insight into the coaction of multiple phytohormones in the regulation of plant growth and development.
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Zhang
authors.forename: Ziqiang
authors.initials: Z
authors.lastname: Zhu
authors.forename: Fengying
authors.initials: F
authors.lastname: An
authors.forename: Dongdong
authors.initials: D
authors.lastname: Hao
authors.forename: Pengpeng
authors.initials: P
authors.lastname: Li
authors.forename: Jinghui
authors.initials: J
authors.lastname: Song
authors.forename: Chengqi
authors.initials: C
authors.lastname: Yi
authors.forename: Hongwei
authors.initials: H
authors.lastname: Guo
mesh_terms: D017360:Arabidopsis / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000502:physiology*; D001483:Base Sequence; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000378:metabolism / Q000502:physiology*; D003517:Cyclopentanes / Q000378:metabolism*; D004268:DNA-Binding Proteins; D015536:Down-Regulation; D024202:Electrophoretic Mobility Shift Assay; D005030:Ethylenes / Q000037:antagonists & inhibitors*; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D015345:Oligonucleotide Probes; D054883:Oxylipins / Q000378:metabolism*; D011485:Protein Binding; D059748:Proteolysis; D014157:Transcription Factors / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D003517:Cyclopentanes; D004268:DNA-Binding Proteins; C106987:EIN3 protein, Arabidopsis; D005030:Ethylenes; C473611:MYC2 protein, Arabidopsis; D009687:Nuclear Proteins; D015345:Oligonucleotide Probes; D054883:Oxylipins; D014157:Transcription Factors; C011006:jasmonic acid; C036216:ethylene