油菜素内酯和脱落酸调控葡萄果实花色苷合成的研究

【目的】为研究2,4-表油菜素内酯(2,4-epibrassinolide,EBR)和脱落酸(abscisic acid,ABA)处理对葡萄花色苷合成与可溶性固形物含量、果皮苯丙氨酸解氨酶(PAL)和类黄酮糖基转移酶(UFGT)活性以及果实内源ABA含量的影响,探索油菜素内酯调控葡萄果实成熟及花色苷合成的机理。【方法】以酿酒葡萄‘赤霞珠’(Cabernet Sauvignon)和‘烟73’(Yan 73)为试材,在葡萄转色前分别用0.1、0.4、0.8 mg.L-1EBR,1mg.L-1Brz(brassinazole,BR生物合成抑制剂)和200 mg.L-1ABA,均匀喷施于葡萄果实,在葡萄成熟过程中测定葡萄果皮花色苷含量及PAL和UFGT酶活性,同时测定果实ABA和可溶性固形物含量。【结果】在果实着色初期,‘赤霞珠’和‘烟73’葡萄果皮PAL和UFGT活性及果实内源ABA含量均逐渐升高,当果实接近成熟花色苷含量基本稳定时ABA含量开始降低。与对照相比,0.4mg.L-1EBR和200 mg.L-1ABA处理显著增加了果实内源ABA含量,提高了果皮PAL和UFGT活性,促进了果皮花色苷的合成和果实可溶性固形物的积累。0.1 mg.L-1和0.8 mg.L-1EBR处理总体增加了果实内源ABA含量,促进了花色苷的合成和可溶性固形物的积累,并提高了UFGT和PAL酶活性,但比0.4 mg.L-1EBR处理提高的幅度小,且差异显著。1 mg.L-1Brz处理使果实ABA的合成推迟,果实可溶性固形物含量、果皮PAL和UFGT活性以及花色苷含量均低于对照,但差异不显著。【结论】外源EBR和ABA处理促进了葡萄成熟和花色苷合成,在不同浓度EBR处理中,以0.4 mg.L-1处理效果较好;内源ABA可能参与了EBR对葡萄成熟和花色苷合成的调控。

Studies on the regulation of anthocyanin biosynthesis in grape berry by brassinosteroid and abscisic acid

【Objective】In order to explore the mechanism of regulation of ripening and anthocyanin biosynthesis in grape berry by brassinosteroids,the effects of 2,4-epibrassinolide(EBR) and abscisic acid(ABA) on anthocyanin biosynthesis,the content of soluble solids and endogenous ABA,the enzyme activities of phenylalanine ammonia-lyase(PAL) and UDP-glucose-flavonoid-3-O-glycosyltransferase(UFGT) in grape skin were studied.【Method】Different concentrations of exogenous 2,4-epibrassinolide(0.1,0.4,0.8 mg·L-1),brassinazole(Brz,1 mg·L-1,an inhibitor of BR biosynthesis) and abscisic acid(ABA,200 mg·L-1)were respectively applied to the berries of wine grape,Cabernet Sauvignon and Yan73,before veraison.The anthocyanin content and the activities of phenylalanine ammonia-lyase(PAL),UDP-glucose-flavonoid-3-O-glycosyltransferase(UFGT) in grape skin were analyzed.The ABA production and the soluble solids were also studied.【Result】The results demonstrated that the activities of PAL and UFGT in berry skin and the content of endogenous ABA in berry increased gradually at the beginning of veraison,and the ABA content decreased when berry was approaching maturity and the content of anthocyanin was stable.After the treatment of grape berries with 0.4 mg·L-1 EBR and 200 mg·L-1 ABA,the content of endogenous ABA in berry,the enzyme activities of PAL and UFGT in skin were significantly higher than that of control,and the biosynthesis of anthocyanin and the accumulation of soluble solids were also significantly promoted.After the application of 0.1 mg·L-1 and 0.8 mg·L-1 EBR to grape berries,the production of endogenous ABA,the content of anthocyanin and soluble solids and the enzyme activities of PAL and UFGT were higher compared with control,but lower significantly with 0.4 mg· L-1 EBR.After the application of 1 mg·L-1 Brz to the grape berries,the biosynthesis of endogenous ABA were delayed,and the content of soluble solids,the activity of PAL and UFGT and the anthocyanin contents of the two cultivars were lower compared with control.【Conclusion】The ripening and anthocyanin biosynthesis of grape were promoted by exogenous 2,4-epibrassinolide(EBR) and ABA,and among all the concentrations of EBR,0.4 mg·L-1 had the most significant effects.The regulation of ripening and anthocyanin biosynthesis of grape by exogenous EBR was associated with the increase in endogenous ABA production.