title: The ethylene response factor AtERF11 that is transcriptionally modulated by the bZIP transcription factor HY5 is a crucial repressor for ethylene biosynthesis in Arabidopsis.
abstract: The phytohormones abscisic acid (ABA) and ethylene are known to play multiple roles in plant development and stress responses. Ethylene biosynthesis is affected by several factors including drought, cold and the phytohormone auxin, although the role of ABA is unclear. In this work ABA-responsive mutants were screened and a bZIP transcription factor HY5 was identified as a negative regulator of ethylene biosynthesis via modulation of the expression of the ethylene biosynthesis genes ACS2 and ACS5. Members of the ethylene response factor (ERF) family of transcriptional repressors in Arabidopsis have been shown to modulate ABA responses and three ERF members were found to carry putative HY5-binding cis-acting elements. Analyses with biochemical and molecular approaches revealed that HY5 specifically binds to the G-box region of the AtERF11 promoter to activate its transcription. We further demonstrate that AtERF11, which contains a repressor motif at its C-terminal, interacts with the dehydration-responsive element in the ACS2/5 promoters, to repress its expression, resulting in decreased ethylene biosynthesis. Moreover, an AtERF11 knockout mutant showed increased levels of ACS2/5 expression and ethylene emission, while treatment with ABA greatly suppressed ACS5 transcripts but not ACS2 expression and the ethylene content, indicating that AtERF11 is a key negative regulator for ABA-mediated control of ethylene synthesis. In addition, in ethylene over-producer mutants, ABA treatment was shown to suppress ACS5 transcripts and ethylene content, thereby affecting growth and development. Based on these data, in this research we present a model suggesting that the HY5-AtERF11 regulon is a key factor modulating ABA-regulated ethylene biosynthesis.
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Zhuofu
authors.initials: Z
authors.lastname: Li
authors.forename: Lixia
authors.initials: L
authors.lastname: Zhang
authors.forename: Yanwen
authors.initials: Y
authors.lastname: Yu
authors.forename: Ruidang
authors.initials: R
authors.lastname: Quan
authors.forename: Zhijin
authors.initials: Z
authors.lastname: Zhang
authors.forename: Haiwen
authors.initials: H
authors.lastname: Zhang
authors.forename: Rongfeng
authors.initials: R
authors.lastname: Huang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D008190:Lyases / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000378:metabolism* / Q000494:pharmacology; D018517:Plant Roots / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D017384:Sequence Deletion; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; C581417:ERF11 protein, Arabidopsis; D005030:Ethylenes; C109254:HY5 protein, Arabidopsis; D009687:Nuclear Proteins; D010937:Plant Growth Regulators; D012097:Repressor Proteins; D014157:Transcription Factors; D000040:Abscisic Acid; C036216:ethylene; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase