Abstract
Transcriptional regulation is essential for bal-ancing multiple metabolic pathways that influ-ence oil accumulation in seeds.Thus far,the transcriptional regulatory mechanisms that govern seed oil accumulation remain largely un-known.Here,we identified the transcriptional regulatory network composed of MADS-box transcription factors SEEDSTICK(STK)and SEPALLATA3(SEP3),which bridges several key genes to regulate oil accumulation in seeds.We found that STK,highly expressed in the devel-oping embryo,positively regulates seed oil ac-cumulation in Arabidopsis(Arabidopsis thaliana).Furthermore,we discovered that SEP3 physically interacts with STK in vivo and in vitro.Seed oil content is increased by the SEP3 mutation,while it is decreased by SEP3 overexpression.The chromatin immunoprecipitation,electrophoretic mobility shift assay,and transient dual-luciferase reporter assays showed that STK positively reg-ulates seed oil accumulation by directly re-pressing the expression of MYB5,SEP3,and SEED FATTY ACID REDUCER 4(SFAR4).More-over,genetic and molecular analyses demon-strated that STK and SEP3 antagonistically reg-ulate seed oil production and that SEP3 weakens the binding ability of STK to MYB5,SEP3,and SFAR4.Additionally,we demonstrated that TRANSPARENT TESTA 8(TT8)and ACYL-ACYL CARRIER PROTEIN DESATURASE 3(AAD3)are direct targets of MYB5 during seed oil accumu-lation in Arabidopsis.Together,our findings provide the transcriptional regulatory network antagonistically orchestrated by STK and SEP3,which fine tunes oil accumulation in seeds.
基金项目
National Key Research and Development Program of China(2022YFD1200400)
National Natural Science Foundation of China(31971974)
Key Research and Development Program of Shaanxi Province(2021LLRH-07)
Key Research and Development Program of Shaanxi Province(2022NY-158)
PhD Startup Fund of Northwest A&F University(Z1090121052)
Yang Ling Seed Industry Innovation Center(K3031122024)
维普
万方数据