Function Of SmbHLH13 In The Synthesis Of Anthocyanin In Solanum Melongena.L

Eggplant is a kind of vegetable which is widely cultivated and edible in China,and is of few vegetables with abundant anthocyanin.Anthocyanin is a kind of natural pigment which widely exists in plants.It can protect plants from abiotic stress and do benefits to human health.Therefore,it is meaningful to study the biosynthesis of anthocyanin deeply and to clarify the mechanism of anthocyanin synthesis and to improve the accumulation of anthocyanin in eggplant.Jasmonic acid(JA)is a kind of plant growth regulator.Early studies have shown that jasmonic acid can promote anthocyanin accumulation in Arabidopsis.However,there is no research on JA-regulated anthocyanin biosynthesis in eggplant.In order to investigate the function of transcription factor SmbHLH13 in anthocyanin biosynthesis and explore the pathway of JA-regulated anthocyanin biosynthesis in eggplant,a series of experiments were done and the results of the study are as follows:1.The transcription factor of SmbHLH13 was cloned.Bioinformatics analysis showed that the gene was 1722 bp in length and encoded 573 amino acids.The results of subcellular localization showed that SmbHLH13 protein was located in the nucleus.Tissue expression pattern analysis showed that SmbHLH13 was expressed most highly in leaves.2.Yeast one-hybrid and dual-luciferase assays showed that SmbHLH13 could activate the promoters of structure genes of Sm CHS and Sm F3 H.3.Genetic transformation of Arabidopsis revealed that overexpression of SmbHLH13 enhanced anthocyanin accumulation and delayed flowering.QRT-PCR and yeast one-hybrid assay showed that maybe SmbHLH13 could bind to the promoter of Sm FT to delay flowering.4.Treating eggplant seedlings with Me JA showed that with the increase of the concentration of Me JA,the anthocyanin accumulation of seedlings increased,the germination rate of seeds decreased,and the growth rate of seedlings slowed down.Moreover,SmbHLH13,SmJAZ1,SmJAZ3 and Sm CHS could respond to JA signal,but Sm F3 H could not.Besides,there was a response element of JA signal in the promoter of Sm CHS.5.Gene SmJAZ1 and SmJAZ3 were cloned.Bioinformatics analysis showed that SmJAZ1 was 594 bp in length and encoded 197 amino acids.SmJAZ3 was 1017 bp in length and encoded 338 amino acids.The results of subcellular localization showed that both SmJAZ1 and SmJAZ3 protein were located in the nucleus and cytoplasm.6.Yeast two-hybrid assay showed that there is an interaction between SmbHLH13 and SmJAZ1/ SmJAZ3.Dual-luciferase assay showed that the interaction between SmbHLH13 and SmJAZ1/ SmJAZ3 could reduce the forward-regulation effect of SmbHLH13 on Sm CHS.