核黄素处理促进‘巨峰’葡萄提早成熟的研究

基于核黄素在光照下易分解产生活性氧的特性,设其浓度梯度为0(对照)、0.1、0.5、1.0mmol·L~(-1),分别于‘巨峰’葡萄花后40 d喷施,研究外源活性氧对葡萄果实发育的影响。结果表明:不同浓度的核黄素处理均可促进‘巨峰’葡萄果实提前成熟,以0.5 mmol·L~(-1)效果最好,使果实提前成熟16 d。0.5 mmol·L~(-1)核黄素处理后,显著提升了果实发育前期可溶性糖及转色期花青苷的含量,果实发育前期过氧化氢(H_2O_2)含量,同时也提高了果胶酶(PG)、纤维素酶及脂氧合酶(LOX)的活性,虽然NADPH氧化酶(NOX)活性有所提升,但超氧化物歧化酶(SOD)活性及超氧阴离子产生速率均下降,推测前期升高的H_2O_2可能来源于LOX等其他途径,而H_2O_2含量的上升并没有引起细胞损伤(MDA含量无差异),适宜浓度的外源活性氧能够启动与葡萄果实快速发育有关活性氧产生途径,从而促进果实的发育。

Studies of the Riboflavin Treatment for Promoting the Early Ripening of 'Kyoho'Grape Berry

Based on the mechanism of superoxide anion can be produced from the photosensitised riboflavin,three different concentrations (0.1,0.5,1.0 mmol · L-1) of riboflavin were set to study the effect of exogenous reactive oxygen species (ROS) on'Kyoho'grape berry development.The results showed that:the riboflavin could promote the development process of grape berry as the exogenous ROS,and the effect of 0.5 mmol · L1 treatment was the best,which resulted in sixteen days earlier of the grape berry ripening than the control.Content of soluble sugar and anthocyanin were increased after the treatment of 0.5 mmol · L-1 riboflavin.At the same time,the hydrogen peroxide (H2O2) content,the pectinase (PG) activity,cellulase activity and lipoxygenase (LOX) activity were all increased at the early development stages of the berry,though the NADPH oxidase (NOX) activity was increased,considering the decreased superoxide dismutase (SOD) activity and production rate of superoxide ion,the increased H2O2 content might generate from other pathway such as LOX.However,the increase H2O2 content did not cause a cell damage (no significant differences of the MDA content).All in all,the appropriate concentration of riboflavin could promote the grape berry ripening by activating the ROS production pathway.