茉莉酸处理对采后葡萄果实贮藏期间落粒的影响

摘要

以＂巨峰＂葡萄果实为试材,研究了茉莉酸甲酯（methyl jasmonate,MeJA）处理对采后葡萄果实在1℃贮藏期间落粒的影响。结果显示：10μmol/L MeJA处理可显著降低葡萄果实贮藏期间落粒率和腐烂率,并延缓果穗离区组织中脱落酸（ABA）含量和乙烯释放量的上升、赤霉素（GA3）含量的下降以及ABA/GA3比值的增长,并显著抑制离区果胶甲酯酶（Pectinesterase,PME）活性的下降和多聚半乳糖醛酸酶（Golygalacturonase,PG）活性的上升。同时,经MeJA处理的果穗离区细胞壁中胶层中乙醇不溶物（AIR）和Na2CO3溶性果胶含量也明显高于对照水平,而水溶性和环己二胺四乙酸（CDTA）溶性果胶含量却低于对照水平。实验表明,MeJA处理可通过调控葡萄果穗离区组织中内源激素水平来平衡细胞壁水解酶PME和PG的活性,从而抑制离区细胞壁中胶层的水解,维持细胞壁结构的完整,最终降低采后葡萄果实的落粒率,起到改善果实贮藏品质的效果。%ABSTRACT The present study was to investigate the effect of the MeJA treatment on grapes fallen from the stems during the storage at 1 C and its mechanism. The results showed that the 10 μmol L-1 MeJA treatment could significantly reduced the fallen rate and decay incidence during the storage, and delayed the increase of ABA content, ethylene release and ABA/GA ratio, and inhibited the decrease in PME activity and increased in PG activi- ty. Meanwhile, the MeJA-treated bunch exhibited significantly higher AIR and Na~CO3-soluble pectin contents com- pared with the controls. The water- and CDTA-soluble pectin contents in the MeJA-treated zone were lower than the controls. Therefore, these results suggested that MeJA treatment significant reduced the fallen rate in harvested grapes and improved fruit quality. The mechanism may be by the regulation of endogenous hormone level and the balance of the activities of cell wall hydrolases PME and PG, which inhibited the hydrolysis in cell wall and maintained the com- plete cell wall structure.