Involvement Of Abscisic Acid In24-epibrassinolide-induced Accumulation Of Anthocyanin In Vitis Vinifera Cv Cabernet Sauvignon

Vitis vinifera L. cv. Cabernet-Sauvignon grapes were sampled from a commercialvineyard in the Chateau Rongzi, Xiangning County, Shanxi Province (China) from July toOctober in2012and July to September in2013, respectively. There were five treatment in2012:(1)100mg/L Abscisic acid (ABA);(2)0.4mg/L24-epibrassinolide (EBR);(3)0.4mg/L EBR+20mg/L Fluridone (Flu);(4)20mg/L Fluridone;(5) water treatment as control(CK); and four treatment in2013:(1)0.4mg/L24-epibrassinolide (EBR);(2)0.4mg/LEBR+15mg/L nordihydroguaiaretic acid (NDGA);(3)15mg/L NDGA;(4) water treatmentas control (CK). The physicochemical indexes of grape berry (reducing sugar, titratable acid),the contents of phenolics compounds (total phenolics, tannins, anthocyanins),the structuralgenes (VvF3H, VvDFR, VvLDOX, VvUFGT, VvGST), the aroma compound of grape berriesand the conpositions and contents of BRs in grape berries were determined. The main resultsas followed:(1) ABA, EBR, EBR+Flu and EBR+NDGA treatment significantly increased thecontent of reducing sugar and reduced titratable acid compared with control. Thess index ofFlu and NDGA treatment had no significant difference with control. The order of increasingsugar of treatments was: ABA＞EBR+Flu (EBR+NDGA)＞EBR＞Flu (NDGA).(2) The total phenolic compounds and tannins in the grape berry skins decreased duringthe veraison and increasing at maturity. ABA and EBR treatment significantly decreasd thetotal phenolic compounds and tannins in the grape berry skins in the veraison and increasedphenolic compound and tannins at maturity. EBR+Flu and EBR+NDGA treatment decreasethe content of total phenolic contents and total tannins except some sampling times, andincreased total phenolic contents and tannins in the ripening. They all had significancedifference with control treatment in the content of total phenolic compounds and total tanninsexcept EBR+Flu treatment. Flu and NDGA treatment had no effect on the content of totalphenolic compounds and total tannins. ABA, EBR EBR+Flu and EBR+NDGA treatmentsignificantly increased the content of total anthocyanins during grape ripening. The content oftotal anthocyanins of Flu and NDGA treatment had no significant difference with control treatment. The order of increasing total anthocyanins content of treatments was: ABA＞EBR+Flu (EBR+NDGA)＞EBR＞Flu (NDGA).(3)33kinds of aroma compounds were measured from the grape berries, including:17kinds of alcohols,2kinds of esters,2kinds of acids,11kinds of aldehyde and ketones.Alcohols, estersand aldehyde and ketones are the3kinds of main aroma compounds, thecontent of ethyl acetate, hexanal and (E)-2-hexanal were higher than others.ABA, EBR andEBR+Flu treatment decreased the content of C6compound. EBR and EBR+Flu treatmentincreased the content of C13-norisoprenoids aroma compounds of grape berries. All thetreatments had no effects on the compositon and compose of the terpenoids in the grapeberries.(4) There were three kinds of BRs measured in the grape berries: castasterone(CS),brassinolide(BL) and6-deoxocastasterone(6-deoxoCS). The content of CS and BL fromgrape berries of control treatment rised and then decrease during veraison. EBR treatmentincreased the content of CS and BL, but had no significant difference with control treatment.The content of CS and BL of EBR treatment kept a high level during the veraison and thecontent of BL was significant higher than other treatment. The content of CS and BL ofNDGA treatment had a downward trend during the veraison, and had no significantdifference compare with control treatment. The content of6-deoxoCS had no obvious changeduring veraison, and all the treatment had no effect on the content of6-dexcoCS.(5) ABA treatment up-regulated the expression of VvF3H, VvDFR, VvLDOX, VvUFGTand VvGST during the grape ripening, especially on the onset of veraison, and the expressiongradual declined during the veraison. EBR treatment increased the expression of VvDFR、VvLDOX and VvUFGT on the onset of veraison and mainly promoted the expression ofVvUFGT from the terminal of veraion to maturity. EBR+Flu and EBR+NDGA treatmentmainly increased the expression of VvLDOX and VvUFGT, the expression of VvLDOXsignificantly up-regulated during the ripening. Flu and NDGA treatment increase theexpression of VvLDOX and the end of veraison.