采后ABA处理促进‘陇薯3号’马铃薯块茎愈伤形成

【目的】研究外源ABA处理对采后‘陇薯3号’马铃薯块茎愈伤效果的影响,分析苯丙烷代谢及抗氧化酶在愈伤中的作用机理。【方法】以‘陇薯3号’马铃薯块茎为试材,人工损伤后用不同浓度脱落酸(ABA)处理,评价处理块茎在常温((20±3)℃,湿度(80±5)%)及黑暗条件下的愈伤效果,分析100 mg·L~(-1)ABA处理后块茎伤口处组织苯丙烷代谢关键酶活性和代谢产物积累以及过氧化物酶和多酚氧化酶的活性变化,扫描电镜观察伤口处愈伤组织的形成过程.【结果】不同浓度ABA处理均有效促进了块茎愈伤,其中以100 mg·L~(-1)的处理效果最好。ABA处理能显著提高块茎伤口处组织苯丙氨酸解氨酶、肉桂酸羟化酶、4-香豆酰-辅酶A-连接酶和肉桂醇脱氢酶的活性,并能使总酚、类黄酮和木质素的含量增加,其中,苯丙氨酸解氨酶的活性呈现双峰型变化,在处理后的第3天和第9天分别高出同期对照253.07%和125.18%。此外,总酚和类黄酮含量在处理后第6天分别较同期对照高出48.60%和50.42%。ABA处理还明显增强了块茎伤口处组织中的过氧化物酶和多酚氧化酶活性。扫描电镜观察结果表明,ABA处理促进了块茎伤口表面愈伤封闭层和周皮的形成。【结论】外源ABA处理可通过促进马铃薯块茎伤口处组织的苯丙烷代谢,提高过氧化物酶和多酚氧化酶活性,加速马铃薯块茎愈伤周皮的形成。

Postharvest ABA Treatment Promote Wound Healing of Potato ‘Longshu No.3’ Tubers

【Objective】The experiment was conducted to study the effects of exogenous abscisic acid (ABA) treatment on wound healing of the potato tubers ‘Longshu No.3’, to analyze the role of phenylpropane metabolism and antioxidant enzymes in wound healing. 【Method】The potato cultivar ‘Longshu No.3’ was used as materials. The tubers were artificially damaged, then treated with different concentrations ABA, and healed under dark condition ((20±3)℃, RH (80±5)%). The healing ability of treated tubers was evaluated. The changes of activity of phenylpropane metabolism key enzymes, peroxidase and polyphenol oxidase were determined. The content of metabolites was determined at wounded site of tubers treated with 100mg·L^-1ABA during healing. The formation of healing tissue was observed by scanning electron microscopy. 【Result】ABA treatment at different concentrations effectively promoted wound healing of tubers, the screened optimum concentration was 100 mg·L^-1. ABA treatment at 100 mg·L^-1 significantly increased the activity of phenylalnine ammonialyase, cinnamic acid hydroxylase, 4-coumaroyl-coenzyme A-ligase and cinnamyl alcohol dehydrogenase, sped the accumulation of total phenols, flavonoids and lignin at wounded site of tubers. In which, the activity of phenylalanine ammonialyase showed bimodal change, the treatment was 253.07% and 125.18% higher than the control after 3 days and 9 days of healing. The content of total phenols and flavonoids of the treatment showed 48.60% and 50.42% higher than that of the control. Moreover, the activities of peroxidase and polyphenol oxidase were significantly enhanced at wounded site of tubers. Observation of scanning electron microscopy showed that the formation of closing layer and wound periderm of tubers were accelerated after ABA treatment. 【Conclusion】Exogenous ABA treatment accelerates the formation of wound periderm of potato tubers by promoting the phenylpropane metabolism, and increasing the activities of peroxidase and polyphenol oxidase.