Effect Of Exogenous ABA And 6-BA Treatments On The Synthesis Of Anthocyanins From Merlot Grape Berries

In order to investigate the effects of different concentrations of ABA and 6-BA on the composition of anthocyanins and relative gene expression as well as selecting the suitable concentration of hormones for grape anthocyanin accumulation,Vitis vinfera L.cv.Merlot produced in Ningxia wine producing area was used as material,different concentrations of exogenous abscisic acid(ABA 300,600,900mg/L)and 6-benzylaminopurine(6-BA 100,200,400mg/L)were applied to berries of grape respectively before veraison(50 days after anthesis).The results are as follow:1.Treatments with 600 mg/L ABA and 200 mg/L 6-BA increased the color percentage of berries compared with control in veraison,which were 5.7 and 3.61 times respectively.Meanwhile,the contents of sucrose,reducing sugar and anthocyanin in grape skin were increased in fruit maturity by the treatments as well as the total content of five kinds of anthocyanins in grape skin,the contents of anthocyanins were 1.46 and 1.43 times respectively in control.Therefore,the optimal concentration of anthocyanin accumulation in the Merlot grape peel was 600 mg/L ABA and 200 mg/L 6-BA respectively.2.The treatment with 600 mg/L ABA significantly increased the content of Malvidin-3-O-glucside after veraison.The content of Malvidin-3-O-glucoside at fruit maturity was 6.02 mg/g,which was 1.45 times of control.The effect of 100 mg/L 6-BA was basically the same as ABA,but it inhibited the content of Cyanidin.3.The expressions of CHSl,F3'H,F3'5'H,UFGT,and MybAl genes in grape berries were significantly improved by 300 and 600 mg/L ABA at 70 days after anthesis,and the expression of PAL and DFR genes was significantly increased at 90 days after anthesis.The results showed that the appropriate concentration of ABA treatments could affect the transcription level of anthocyanin synthesis relevant genes during fruit coloration.4.The treatments of 100 and 200mg/L 6-BA significantly up-regulated the expression of CHS1,F3'H and F3'5'H genes at 70 days after anthesis,and the expression levels of PAL,UFGT and MybAl genes at 90 days after anthesis were increased significantly as well.The results indicated that low concentration of 6-BA has influence on the expression level of anthocyanin synthesis relevant genes in the late stage of veraison and the initial ripening period.Meanwhile,the treatments of ABA and 6-BA could improve the correlation between structural genes CHS1,F3'H,F3'5'H UFGT and transcription factor MybAl,making them positively related,and then regulate grape anthocyanin synthesis.