棉花内生蜡状芽孢杆菌YUPP-10对棉花黄萎病的防治作用及机制

发布时间：2018-11-01 12:17

【摘要】：【目的】棉花黄萎病(Verticillium wilt)是世界性难以防治的病害,筛选有效的生防微生物资源成为解决棉花黄萎病的重要途径之一,本研究旨在分离一株高效拮抗细菌,并明确其防治机理,为生物防治棉花黄萎病提供技术支持。【方法】用葡甘聚糖作为碳源筛选一株能够降解β-1,4糖苷键的棉花内生细菌YUPP-10,通过平板对峙培养、平板对扣培养和悬滴法等测定YUPP-10对大丽轮枝菌(Verticillium dahliae)菌丝生长和孢子萌发的抑制效果;用YUPP-10无菌滤液培养大丽轮枝菌微菌核,检测其对微菌核萌发的影响;利用基质接种法进行盆栽试验探究其对棉花黄萎病的防治效果;通过胚根、叶片接种病原菌,木质化和活性氧爆发研究YUPP-10诱导抗病能力;采用实时荧光定量PCR(qRT-PCR)方法检测防御相关基因的表达。【结果】成功获取一株蜡状芽孢杆菌(Bacillus cereus)YUPP-10,其整体代谢产物在7 d时对大丽轮枝菌的抑菌带宽为0.73 cm,挥发性代谢产物在10 d时对大丽轮枝菌菌落的抑制率为77.03%;YUPP-10无菌培养液对大丽轮枝菌孢子和菌核萌发的抑制率分别为17.22%—71.25%和10.69%—26.62%,且抑制率与无菌滤液的浓度呈正相关。在用YUPP-10玉米蛭石培养物拌土处理的盆栽试验中,其对棉花黄萎病的最高防效达到80.60%。诱导抗性试验发现YUPP-10诱导了胚根和叶片抗大丽轮枝菌的侵染,诱导了细胞木质化和活性氧的爆发。qRT-PCR检测结果显示YUPP-10成功激活了苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)、几丁质酶(CHI)和病程相关基因(PR10)的表达,对大丽轮枝菌在棉花体内的扩散和生长起到了抑制作用。【结论】YUPP-10通过直接抑制病原菌的生长,同时诱导植物防御反应来抵抗病原菌的侵染和扩展,其具有良好的应用前景。
[Abstract]:[objective] Verticillium wilt (Verticillium wilt) is a difficult disease in the world. Screening effective biocontrol microbial resources is one of the important ways to solve cotton verticillium wilt. To provide technical support for biological control of cotton verticillium wilt. [methods] A strain of cotton endophytic bacteria YUPP-10, which could degrade 尾 -1d4 glucoside bond, was screened by using glucomannan as carbon source. The inhibition effect of YUPP-10 on (Verticillium dahliae) mycelium growth and spore germination was determined by plate clasping culture and suspension drop method. The microsclerotic sclerotia of Verticillium dahliensis was cultured with YUPP-10 aseptic filtrate, the effect of microsclerotia on the germination of microsclerotia was detected, the pot experiment was carried out by substrate inoculation, and the control effect on Verticillium wilt of cotton was investigated. The disease resistance induced by YUPP-10 was studied by inoculation of pathogenic bacteria in radicle and leaf, lignification and reactive oxygen species explosion. The expression of defense-related genes was detected by real-time fluorescence quantitative PCR (qRT-PCR). [results] A Bacillus cereus (Bacillus cereus) YUPP-10, strain was successfully obtained. The inhibition rate of the whole metabolite to the colony of Armillaria dahliae was 77.03 at 10 days. The inhibition bandwidth of the whole metabolite was 0. 73 cm, on the rhizome of Armillaria dahliensis. The inhibition rate of the volatile metabolite was 77. 03% at 10 days. The inhibitory rates of YUPP-10 aseptic medium on sclerotia germination and spore germination were 17.22 and 10.69- 26.62%, respectively, and the inhibition rate was positively correlated with the concentration of aseptic filtrate. In pot experiment with YUPP-10 corn vermiculite culture mixed with soil, the highest control effect on Verticillium wilt of cotton was 80.60%. The induced resistance test found that YUPP-10 induced radicle and leaf resistance to Rhizoctonia grandis, and induced cell lignogenesis and reactive oxygen species outbreak. QRT-PCR results showed that YUPP-10 successfully activated phenylalanine ammonia-lyase (PAL),. Expression of peroxidase (POD), polyphenol oxidase (PPO), chitinase (CHI) and pathogenesis-related gene (PR10). [conclusion] YUPP-10 can directly inhibit the growth of pathogenic bacteria and induce plant defense to resist the infection and expansion of the pathogen. It has a good application prospect.
【作者单位】：长江大学农学院;中国农业科学院棉花研究所/棉花生物学国家重点实验室;
【基金】：国家公益性行业(农业)科研专项(201503109) 中央级公益性科研院所基本科研业务费专项(1610162016012)
【分类号】：S435.621.2;S476.1

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