Arabidopsis MYC2 interacts with DELLA proteins in regulating sesquiterpene synthase gene expression.
Arabidopsis thaliana flowers emit volatile terpenes, which may function in plant-insect interactions. Here, we report that Arabidopsis MYC2, a basic helix-loop-helix transcription factor, directly binds to promoters of the sesquiterpene synthase genes TPS21 and TPS11 and activates their expression. Expression of TPS21 and TPS11 can be induced by the phytohormones gibberellin (GA) and jasmonate (JA), and both inductions require MYC2. The induction of TPS21 and TPS11 results in increased emission of sesquiterpene, especially (E)-β-caryophyllene. DELLAs, the GA signaling repressors, negatively affect sesquiterpene biosynthesis, as the sesquiterpene synthase genes were repressed in plants overaccumulating REPRESSOR OF GA1-3 (RGA), one of the Arabidopsis DELLAs, and upregulated in a penta DELLA-deficient mutant. Yeast two-hybrid and coimmunoprecipitation assays demonstrated that DELLAs, represented by RGA, directly interact with MYC2. In yeast cells, the N terminus of MYC2 was responsible for binding to RGA. MYC2 has been proposed as a major mediator of JA signaling and crosstalk with abscisic acid, ethylene, and light signaling pathways. Our results demonstrate that MYC2 is also connected to GA signaling in regulating a subset of genes. In Arabidopsis inflorescences, it integrates both GA and JA signals into transcriptional regulation of sesquiterpene synthase genes and promotes sesquiterpene production.
National Key Laboratory of Plant Molecular Genetics and National Plant Gene Research Center, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Shanghai 200032, People's Republic of China.
Gao-Jie
GJ
Hong
Xue-Yi
XY
Xue
Ying-Bo
YB
Mao
Ling-Jian
LJ
Wang
Xiao-Ya
XY
Chen
D019883:Alkyl and Aryl Transferases / Q000235:genetics* / Q000378:metabolism; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant; D005875:Gibberellins / Q000378:metabolism / Q000494:pharmacology; D056626:Inflorescence / Q000235:genetics / Q000378:metabolism; D008027:Light; D009154:Mutation; D054883:Oxylipins / Q000378:metabolism / Q000494:pharmacology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D000081223:Polycyclic Sesquiterpenes; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D012717:Sesquiterpenes / Q000378:metabolism*; D015398:Signal Transduction; D020798:Two-Hybrid System Techniques
D029681:Arabidopsis Proteins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D003517:Cyclopentanes; D005875:Gibberellins; C473611:MYC2 protein, Arabidopsis; D054883:Oxylipins; D000081223:Polycyclic Sesquiterpenes; C508468:RGA protein, Arabidopsis; D012097:Repressor Proteins; D012717:Sesquiterpenes; C011006:jasmonic acid; C024714:caryophyllene; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase