油菜素内酯对高温胁迫下葡萄花色苷合成及果实品质的影响

Effects of Brassinolide Treatment on Anthocyanin Synthesis and Quality in Grape Under High Temperature Stress

以酿酒葡萄‘赤霞珠’(Vitis vinfera‘Cabernet Sauvignon’)为试材,于果实转色期前一周对整株喷施2,4–表油菜素内酯(2,4-brassinolide,EBR),采用红外辐射器模拟增温环境,研究EBR处理对高温胁迫下果实成熟过程中花色苷合成及果实品质的影响。结果表明,高温降低了花色苷含量,下调了花色苷合成相关基因VvCHS、VvDFR、VvLDOX和VvMybA1的表达量。转色初期(花后63d),高温处理的果实着色率比对照减少了17.80%。EBR提高了花色苷和可溶性糖的含量。花后77 d,高温+EBR处理与高温处理相比,果实花色苷含量提高了21.65%。果实成熟后期,高温+EBR处理VvCHS与VvLDOX表达量分别是高温处理的3.27和2.21倍。相关性分析显示,高温+EBR处理下花色苷含量与VvMybA1转录水平呈极显著正相关;可溶性糖与花色苷含量呈显著正相关。葡萄外源EBR处理可提高转色初期花色苷含量,改善果实着色,促进总糖和总酚积累,有效缓解高温对果实品质的影响。

To study the effects of 2,4-Epibrassinolide(EBR)on anthocyanin synthesis and berry quality under high temperature stress,Vitis vinifera L.‘Cabernet Sauvignon’were used as the material.Before veraison,grapevines were sprayed with EBR and conducted the heat stress experiments,which simulated by the infrared radiator.Results indicated that the anthocyanin contents were reduced and the expression levels of the anthocyanin synthesis genes such as VvCHS,VvDFR,VvLDOX,and VvMybA1 were down-regulated after heat stress.At the beginning of veraison,compared with the control,the berry coloring rate was reduced by 17.80%after the high-temperature treatment.EBR treatments increased the contents of anthocyanin and soluble sugar in grape berry.The content of anthocyanins in high temperature with EBR treatment was increased by 21.65%compared with only the high temperature group at 77 d after anthesis.At the late ripening stage,the gene expression levels of VvCHS and VvLDOX in high temperature with EBR were 3.27 and 2.21 time folds of those in the high temperature group.Further analysis showed that the content of anthocyanins was significant positively correlated with the transcription level of VvMybA1 under the high temperature+EBR treatment.Moreover,there is a positive correlation relationship between sugar and anthocyanin.In conclusion,the treatment with EBR could increase anthocyanin content,improve berry coloring,promote sugar and total phenols accumulation,and effectively alleviate the effect of high temperature on berry quality in‘Cabernet Sauvignon’.