title: Abscisic Acid Antagonizes Ethylene Production through the ABI4-Mediated Transcriptional Repression of ACS4 and ACS8 in Arabidopsis.
abstract: Increasing evidence has revealed that abscisic acid (ABA) negatively modulates ethylene biosynthesis, although the underlying mechanism remains unclear. To identify the factors involved, we conducted a screen for ABA-insensitive mutants with altered ethylene production in Arabidopsis. A dominant allele of ABI4, abi4-152, which produces a putative protein with a 16-amino-acid truncation at the C-terminus of ABI4, reduces ethylene production. By contrast, two recessive knockout alleles of ABI4, abi4-102 and abi4-103, result in increased ethylene evolution, indicating that ABI4 negatively regulates ethylene production. Further analyses showed that expression of the ethylene biosynthesis genes ACS4, ACS8, and ACO2 was significantly decreased in abi4-152 but increased in the knockout mutants, with partial dependence on ABA. Chromatin immunoprecipitation-quantitative PCR assays showed that ABI4 directly binds the promoters of these ethylene biosynthesis genes and that ABA enhances this interaction. A fusion protein containing the truncated ABI4-152 peptide accumulated to higher levels than its full-length counterpart in transgenic plants, suggesting that ABI4 is destabilized by its C terminus. Therefore, our results demonstrate that ABA negatively regulates ethylene production through ABI4-mediated transcriptional repression of the ethylene biosynthesis genes ACS4 and ACS8 in Arabidopsis.
authors.affiliation: College of Biological Sciences, China Agricultural University, Beijing 100193, China; Plant Molecular Biology Department, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; National Key Facility of Crop Gene Resources and Genetic Improvement, Beijing 100081, China.
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Dong
authors.affiliation: Plant Molecular Biology Department, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Yanwen
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Plant Molecular Biology Department, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Shenghui
authors.initials: S
authors.lastname: Li
authors.affiliation: Plant Molecular Biology Department, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; National Key Facility of Crop Gene Resources and Genetic Improvement, Beijing 100081, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Biological Sciences, China Agricultural University, Beijing 100193, China. Electronic address: saijuntang@gmail.com.
authors.forename: Saijun
authors.initials: S
authors.lastname: Tang
authors.affiliation: Plant Molecular Biology Department, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; National Key Facility of Crop Gene Resources and Genetic Improvement, Beijing 100081, China. Electronic address: rfhuang@caas.cn.
authors.forename: Rongfeng
authors.initials: R
authors.lastname: Huang
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D005030:Ethylenes / Q000096:biosynthesis*; D018506:Gene Expression Regulation, Plant; D008190:Lyases / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: C470421:ABI4 protein, Arabidopsis; D029681:Arabidopsis Proteins; D005030:Ethylenes; D014157:Transcription Factors; D000040:Abscisic Acid; C036216:ethylene; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase
keywords: ABA; ABI4; ethylene biosynthesis; stress response; transcriptional regulation