褪黑素抑制‘贵长’猕猴桃软腐病的生理生化机制  

Physiological and biochemical mechanisms of melatonin inhibition of soft rot in ’Guichang’ kiwifruit

作　　者：彭俊森 罗登灿 万璇 聂娇娇 董晓庆 PENG Junsen;LUo Dengcan;WAN Xuan;NIE Jiaojiao;DONG Xiaoqing(College of Agriculture,Guizhou University/Guizhou Engineering Research Centre for Fruits Crops,Guiyang 550025,China)

机构地区：[1]贵州大学农学院/贵州省果树工程技术研究中心,贵阳550025

出　　处：《植物生理学报》2022年第12期2401-2410,共10页Plant Physiology Journal

基　　金：贵州省自然科学基金(黔科合基础20201Y122)。

摘　　要：本试验以‘贵长’猕猴桃(Actinidia chinensis var. deliciosa ‘Guichang’)为材料,通过离体试验筛选出最佳褪黑素(MT)抑菌浓度,测定最佳浓度褪黑素处理对猕猴桃果实接种葡萄座腔菌(Botryosphaeria dothidea)后病斑直径和相关防御酶的活性变化并结合相关性分析探讨抗性机制。结果表明, 500μmol·L^(-1)褪黑素对B. dothidea菌丝生长有显著抑制作用,其抑菌率可达50.69%,且在果实上能显著抑制病斑直径的扩大。褪黑素处理不仅能够延缓‘贵长’猕猴桃失重率的上升,显著提高超氧化物歧化酶(SOD)、过氧化物酶(POD)活性和总酚含量,且能诱导几丁质酶(CHI)、β-1,3-葡聚糖酶(GLU)等病程蛋白的活性提高,减少丙二醛(MDA)含量,从而提高猕猴桃果实对软腐病的抗性。综上,褪黑素通过激活抗氧化酶以及病程蛋白活性的提高来诱导猕猴桃对软腐病的抗性。In this study, the best melatonin inhibitory concentration was screened out in in vitro test using ’Guichang’ kiwifruit(Actinidia chinensis var. deliciosa) as the experimental material. The changes in spot diameter and related defense enzyme activities of kiwifruit fruit inoculated with B. dothidea were determined and correlation analysis was conducted to explore the resistance mechanism. The results illustrateded that 500 μmol·L^(-1)melatonin had a dramatic inhibitory effect on the mycelial growth of B. dothidea and its antibacterial rate was up to 50.69%, and it could also significantly inhibited the expansion of the spot diameter on the fruit. Melatonin treatment not only delayed the rise in weight loss of ’Guichang’ kiwifruit, but also remarkably increased superoxide dismutase(SOD) and peroxidase(POD) activities and total phenolic content, induced an increase in the activities of disease process proteins such as chitinase(CHI)and β-1,3-glucanase(GLU), and reduced malondialdehyde(MDA) content, thus improving kiwifruit fruit resistance to soft rot. In summary, melatonin induces resistance to soft rot in kiwifruit by activating antioxidant enzymes and enhancing the activities of disease process proteins.

关 键 词：猕猴桃 褪黑素 软腐病 诱导 抗性 

分 类 号：S436.634.1[农业科学—农业昆虫与害虫防治]