采前喷施水杨酸对红地球葡萄采后果实软化的影响

Effect of spraying salicylic acid to pre-harvest fruit on softening of postharvest Vitis vinifera L.cv.red globe

为探究采前喷施水杨酸(salicylic acid,SA)处理对红地球葡萄采后果实软化进程的影响,以红地球葡萄为材料,采前喷施1.0 mmol/L SA处理,采收预冷后在常温(22±1)℃贮藏,分析果实品质、原果胶(protopectin,PP)、纤维素、水溶性果胶(water soluble pectin,WSP)含量、细胞壁代谢相关酶活性及基因相对表达量的变化。结果表明,SA能有效延缓失重率、腐烂率和果梗褐变指数上升,硬度、PP和纤维素含量的下降以及WSP含量的增加;抑制果实多聚半乳糖醛酸酶(polygalacturonase,PG)、果胶甲酯酶(pectin methylesterase,PME)、纤维素酶(cellulase,Cx)、β-半乳糖苷酶(β-galactosidase,β-Gal)和β-葡萄糖苷酶(β-glucosidase,β-Glu)活性上升及其相关基因(VvPG、VvPME、Vvβ-Glu和Vvβ-Gal)的表达。采前喷施SA处理可以通过调节细胞壁代谢途径延缓葡萄果实采后软化,PG、PME、Cx、β-Glu和β-Gal参与了红提葡萄果实的软化过程,可延长葡萄的货架期,减少采后因软化和腐烂等问题造成的经济损失,提高葡萄采后食品安全性。

To investigate the effects of pre-harvest spraying salicylic acid(SA)on the softening process of postharvest grapes,red globe grape was used as material with the spraying of 1.0 mmol/L SA before harvest,and then stored at room temperature(22±1)℃after pre-cooling.The changes of fruit quality,protopectin(PP),cellulose,water soluble pectin(WSP)contents,cell wall metabolism-related enzyme activities and relative gene expression were analyzed.The results showed that SA could effectively delay the increase of weight loss and decay rate,browning index of fruit stem as well.SA also could decrease the hardness,PP and cellulose content,and increase WSP content.Moreover,SA inhibited the activities of polygalacturonase(PG),pectin methylesterase(PME),cellulase(Cx),β-glucosidase(β-Glu),β-galactosidase(β-Gal)and the expressions of related genes(VvPG,VvPME,Vvβ-Glu and Vvβ-Gal)in fruits.Furthermore,PG,PME,Cx,β-Glu andβ-Gal were involved in the softening process of red grape fruits,which can prolong the shelf life of grapes,reduce the economic losses caused by postharvest softening and rot,and improve the safety of postharvest grapes.