谷胱甘肽对切花月季‘Samantha’失水胁迫耐性的影响

采用外源谷胱甘肽（GSH）及其生物合成关键酶γ–谷氨酰半胱氨肽合成酶（γ-ECS）的专一抑制剂丁胱亚磺酰胺（BSO）分别处理切花月季‘Samantha’花枝基部，以提高或降低花瓣中的GSH含量，研究GSH对月季切花失水胁迫耐性的影响，以及花瓣中抗坏血酸–谷胱甘肽（AsA-GSH）循环对失水胁迫的响应。结果表明：提高花瓣中GSH的含量，明显提高了失水胁迫24 h后切花的复水率，延长了瓶插寿命；相反，BSO预处理降低了花瓣中的GSH含量，从而降低了切花的失水胁迫耐性。GSH预处理在明显提高失水胁迫和复水期间花瓣中GSH总含量和还原型GSH含量的同时也提高了抗坏血酸（AsA）的含量；AsA-GSH循环中两个关键酶抗坏血酸过氧化物酶（APX）和谷胱甘肽还原酶（GR）的活性也明显高于胁迫对照，并且MDA的含量明显降低。BSO预处理则产生相反的效果。这些结果表明，GSH能够通过提高AsA-GSH循环的抗氧化能力来增强月季切花的失水胁迫耐性。

Effects of GSH on Tolerance to Water Deficit Stress in Cut Rose

To investigate the effects of GSH on tolerance to water deficit stress (WDS) in cut rose 'Samantha' and the response of AsA-GSH cycle to WDS in petals of cut roses, we pretreated the stem bases of cut rose flowers with exogenous GSH and BSO, the specific inhibitor of GSH key biosynthetic enzyme γ-ECS, to increase or decrease GSH content of cut rose petals respectively. The results showed that GSH pretreatment increased water recovery rate after 24 h WDS and prolonged vase life significantly; On the contrary, BSO pretreatment decreased the GSH content of petals and then, reduced the tolerance to WDS in cut roses. GSH pretreatment increased the total GSH content and reduced GSH content of petals substantially during WDS and water recovery, as well as AsA content. GSH pretreatment promoted the activities of APX and GR, which were two key enzymes in AsA-GSH cycle, but MDA content decreased.Contrary results were obtained in BSO pretreatment. These results suggested that GSH enhanced the tolerance to WDS through the promotion of antioxidant capability of AsA-GSH cycle in cut roses.