硫氢化钠诱导采后香蕉耐冷性的研究

Sodium Hydrosulfide-induced Chilling Resistance in Postharvest Bananas

研究了硫氢化钠(Sodium hydrosulfide,Na HS)处理对香蕉果实冷害的影响。在20℃下,在密闭容器中,采后香蕉果实经0.5 mmol/L Na HS处理24 h后,置于7℃贮藏14 d。研究发现,与对照相比,Na HS处理延缓了香蕉果皮细胞膜透性和丙二醛(Malondialdehyde,MDA)含量的增加,提高了过氧化氢酶(Catalase,CAT)、过氧化物酶(Peroxidase,POD)、抗坏血酸过氧化物酶(Ascorbate peroxidase,APX)和谷胱甘肽还原酶(Glutathione reductase,GR)等抗氧化酶活性,降低了O2-的生成速率和H2O2的含量,促进了香蕉果皮酚类物质的积累并增加了还原型谷胱甘肽(Glutathione,GSH)含量,提高了总抗氧化能力。至贮藏14 d,经Na HS处理的香蕉的冷害指数比对照低5.00%,相对电导率和MDA含量分别比对照低5.36%和10.26%,CAT、POD、APX和GR活性分别比对照高36.77%,35.59%,6.81%和21.93%,O2-的生成速率和H2O2的含量分别比对照低11.39%和18.78%,总酚和GSH含量分别比对照高12.12%和1.27%。研究结果表明硫化氢(hydrogen sulfide,H2S)可作为信号分子诱导采后香蕉果实的耐冷能力。

The effects of exogenous sodium hydrosulfide（Na HS） treatment on chilling injures in postharvest bananas were investigated. Harvested banana fruits were treated with 0.5 m M/L Na HS at 20 ℃ for 24 h in a sealed container, and subsequently stored at 7 ℃ for 14 days. Na HS treatment delayed the increase in membrane permeability and malondialdehyde（MDA） content, increased antioxidase enzyme（catalase [CAT], peroxidase [POD], ascorbate peroxidase [APX], and glutathione reductase [GR]） activity, and reduced the rate of generation of superoxide anion（O2-） and hydrogen peroxide（H2O2） content in treated banana peels, as opposed to the untreated, control fruits. Na HS treatment also enhanced the accumulation of total phenolics, led to an increase in reduced glutathione（GSH） content, and enhanced total antioxidant capacity. After the 14-day cold storage period, the chilling injury index, relative conductivity, MDA content, O2- generation rate, and H2O2 content in banana fruits treated with Na HS were 5.00%, 5.36%, 10.26%, 11.39%, and 18.78% lower, respectively, than those in the control fruits; CAT, POD, APX, and GR activities were 36.77%, 35.59%, 6.81%, and 21.93% higher, respectively, than those in the control fruits. Moreover, the total phenolics and GSH content in the fruit treated with Na HS were 11.39% and 18.78% higher, respectively, than those in the control fruits. These results suggest that hydrogen sulfide could be used as a signaling molecule to induce chilling resistance in postharvest banana fruits.