title: The Arabidopsis MYB96 Transcription Factor Is a Positive Regulator of ABSCISIC ACID-INSENSITIVE4 in the Control of Seed Germination.
abstract: Seed germination is a key developmental transition that initiates the plant life cycle. The timing of germination is determined by the coordinated action of two phytohormones, gibberellin and abscisic acid (ABA). In particular, ABA plays a key role in integrating environmental information and inhibiting the germination process. The utilization of embryonic lipid reserves contributes to seed germination by acting as an energy source, and ABA suppresses lipid degradation to modulate the germination process. Here, we report that the ABA-responsive R2R3-type MYB transcription factor MYB96, which is highly expressed in embryo, regulates seed germination by controlling the expression of abscisic acid-insensitive4 (ABI4) in Arabidopsis (Arabidopsis thaliana). In the presence of ABA, germination was accelerated in MYB96-deficient myb96-1 seeds, whereas the process was significantly delayed in MYB96-overexpressing activation-tagging myb96-ox seeds. Consistently, myb96-1 seeds degraded a larger extent of lipid reserves even in the presence of ABA, while reduced lipid mobilization was observed in myb96-ox seeds. MYB96 directly regulates ABI4, which acts as a repressor of lipid breakdown, to define its spatial and temporal expression. Genetic analysis further demonstrated that ABI4 is epistatic to MYB96 in the control of seed germination. Taken together, the MYB96-ABI4 module regulates lipid mobilization specifically in the embryo to ensure proper seed germination under suboptimal conditions.
authors: Department of Bioactive Material Sciences and Research Center of Bioactive Materials (K.L., H.G.L., P.J.S.) and Department of Chemistry and Research Institute of Physics and Chemistry (P.J.S.), Chonbuk National University, Jeonju 561-756, Republic of Korea; andDepartment of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 560-500, Republic of Korea (S.Y., H.U.K.).
authors: Kyounghee
authors: K
authors: Lee
authors: Department of Bioactive Material Sciences and Research Center of Bioactive Materials (K.L., H.G.L., P.J.S.) and Department of Chemistry and Research Institute of Physics and Chemistry (P.J.S.), Chonbuk National University, Jeonju 561-756, Republic of Korea; andDepartment of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 560-500, Republic of Korea (S.Y., H.U.K.).
authors: Hong Gil
authors: HG
authors: Lee
authors: Department of Bioactive Material Sciences and Research Center of Bioactive Materials (K.L., H.G.L., P.J.S.) and Department of Chemistry and Research Institute of Physics and Chemistry (P.J.S.), Chonbuk National University, Jeonju 561-756, Republic of Korea; andDepartment of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 560-500, Republic of Korea (S.Y., H.U.K.).
authors: Seongmun
authors: http://orcid.org/0000-0001-7263-8036
authors: S
authors: Yoon
authors: Department of Bioactive Material Sciences and Research Center of Bioactive Materials (K.L., H.G.L., P.J.S.) and Department of Chemistry and Research Institute of Physics and Chemistry (P.J.S.), Chonbuk National University, Jeonju 561-756, Republic of Korea; andDepartment of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 560-500, Republic of Korea (S.Y., H.U.K.).
authors: Hyun Uk
authors: HU
authors: Kim
authors: Department of Bioactive Material Sciences and Research Center of Bioactive Materials (K.L., H.G.L., P.J.S.) and Department of Chemistry and Research Institute of Physics and Chemistry (P.J.S.), Chonbuk National University, Jeonju 561-756, Republic of Korea; andDepartment of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju 560-500, Republic of Korea (S.Y., H.U.K.) pjseo1@jbnu.ac.kr.
authors: Pil Joon
authors: PJ
authors: Seo
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004843:Epistasis, Genetic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018525:Germination / Q000187:drug effects; D005875:Gibberellins / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D012639:Seeds / Q000187:drug effects / Q000235:genetics / Q000254:growth & development*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects
chemical_list: C470421:ABI4 protein, Arabidopsis; D029681:Arabidopsis Proteins; D005875:Gibberellins; C544823:MYB96 protein, Arabidopsis; D014157:Transcription Factors; D014280:Triglycerides; D000040:Abscisic Acid