Analysis Of Anthocyanin Content In Eggplant Peel And Molecular Mechanism Of Anthocyanin Biosynthesis Regulated By SmMYB6

In this study,firstly,three kinds of eggplant varieties with different colors were screened out by measuring the contents of anthocyanin,flavonoid and total phenol in the eggplant peel.Based on this,pRII-SmMYB6(+)transgenic eggplant line was obtained by Agrobacterium-mediated method using the autocross lines of the above three varieties with multiple generations of self-crossing,and the transcriptional regulatory function of SmMYB6 in eggplant anthocyanin biosynthesis was studied.The main findings are as follows:1.The contents of anthocyanin,flavonoid and total phenol in the black-purple eggplant variety 59 were higher,which was significantly higher than that of other varieties.However,the anthocyanin and flavonoid contents were significantly different among the different color eggplant varieties.The green and orange peels eggplant varieties contained almost no anthocyanin;the white and green eggplant peels contained low content of flavonoid.According to the color of the eggplant peel,the content of total phenol in the eggplant peel was purple eggplant>orange eggplant>green eggplant>white eggplant varieties.2.The total polyphenol content and the DPPH· free radical clearance rate in eggplant peel of different color eggplant varieties were higher than that of eggplant pulp.The total polyphenol content and DPPH· free radical clearance rate were higher in black-purple eggplant peel and orange red eggplant pulp,which was significantly higher than other varieties.The total polyphenol content order in the eggplant peel was purple eggplant >green eggplant>orange eggplant>white eggplant varieties.The DPPH·free radical clearance rate order in eggplant peel was purple eggplant>orange eggplant>white eggplant>green eggplant varieties.The total polyphenol content in eggplant pulp was orange eggplant>green eggplant> white eggplant=purple eggplant.The order of DPPH·free radical clearance rate in eggplant pulp is orange eggplant>white eggplant>green eggplant> purple eggplant vatieties.3.Using Agrobacterium-mediated method obtained pRII-SmMYB6 transgenic eggplant 14 lines successfully.The transgenic callus was purple due to the accumulation of anthocyanin,and the anthocyanin accumulation was found in the leaves and fruit calyx of the transgenic lines.However,due to the different expression levels of SmMYB6 in different lines,the phenotype of the leaves changed significantly.Compared with WT fruits,transgenic fruits showed different anthocyanin accumulations.108 overexpressed transgenic eggplant(OE)fruits showed a tendency of continuous accumulation during the growth process.Fruits gradually changed from shallow to deep and concentrated at the top of the fruit.While 109 overexpressed transgenic eggplant(OE)fruits peel became purple from fruit setting started.It was completely purple,but the fruit was significantly smaller and there was no seed.4.The expression of SmMYB6 was significantly increased in the transgenic eggplant lines,but the expression levels of structural genes SmCHS,SmCHI,SmF3 H,SmDFR,SmANS,and SmFLS were all increased,and the expression of SmDFR was significantly increased.It was suggested that SmMYB6 plays an important role in the synthesis of anthocyanin in eggplant.SmMYB6 may regulate the synthesis of anthocyanin by regulating the expression of structural gene SmDFR.