切割伤害对油桃果实后熟软化及乙烯合成的影响

Effect of Cutting Injury on Post-ripening, Softening and Ethylene Biosynthesis in Nectarine (Prunus persica (L.) Batsch var. nucipersica (Suckow) C. Schneider) Fruits

研究鲜切油桃果实贮藏过程中,不同切割层面的细胞壁多糖降解相关酶和膜脂过氧化作用相关酶活性及乙烯生成量、1-氨基环丙烷-1-羟酸合成酶(ACS)、1-氨基环丙烷-1-羟酸氧化酶(ACO)活性的变化,旨在探讨鲜切油桃果实不同切割层面乙烯生成机制及其与果实成熟软化的关系。结果表明:鲜切油桃2d时便出现ACS和ACO活性高峰以及乙烯释放量高峰,明显早于多聚半乳糖醛酸酶(PG)活性高峰和酯氧合酶(LOX)活性高峰,说明切割伤害引发的乙烯大量生成启动了细胞壁水解进程及膜质过氧化作用的发生。切割上层细胞壁水解和膜质过氧化作用的程度最为严重,2d时切割上层细胞的原果胶含量比对照低83.7%,丙二醛含量比对照高57%。

Changes in activities of enzymes related with cell wall polysaccharides degradation or membrane lipid peroxidation, ethylene production and ACC oxidase （ACO） and ACC synthase （ACS） activities were measured during 10 ℃ storage of fresh- cut nectarine fruits to probe into mechanism for ethylene production and its relationship with fruit softening. Results showed that the appearance of ethylene production peak, ACO and ACS activity peak, which appeared on the second day of storage, were earlier than that of polygalacturonase or lipoxygenase activity. These phenomena indicate that increased ethylene produc- tion induced by cutting injury triggers the process of cell wall hydrolysis and membrane lipid peroxidation. Cell wall hydrolysis and membrane lipid peroxidation were more serious in upper layer of cutting area than in other layers. After 2 days, the protopectin content in upper layer was decreased by 83.7% and the malondialdehyde （MDA） content by 57%, compared with control nectarine fruits.