印度梨形孢诱导烟草对黑胫病的抗性及其机理的初步研究  

Piriformospora indica Inducing Tobacco Resistance to Black Shank and Its Preliminary Mechanism

作　　者：彭兵[1] 刘剑 惠非琼 王玉平 高其康[3] 楼兵干[1] 

机构地区：[1]浙江大学生物技术研究所,杭州310058 [2]贵州中烟工业有限责任公司,贵阳550001 [3]浙江大学农生环测试中心,杭州310058

出　　处：《农业生物技术学报》2015年第4期432-440,共9页Journal of Agricultural Biotechnology

基　　金：贵州中烟工业有限责任公司科技项目(No.201216)

摘　　要：印度梨形孢（Piriformospora indica）是分离自印度塔尔沙漠的植物根系内生真菌,能够诱导多种植物对生物和非生物逆境产生抗性,目前已作为一种模式真菌用于内生真菌与植物互作关系的研究.为了研究印度梨形孢对烟草（Nicotiana tobacum）抗黑胫病的影响,本研究采用烟草疫霉菌（Phytophthora parasitica var.nicotianae）分别接种根部有印度梨形孢定殖与未定殖的烟草,观察接种后根部有印度梨形孢定殖与未定殖的烟草发病情况,测定抗病相关防御酶苯丙氨酸解氨酶（PAL）、过氧化物酶（POD）、多酚氧化酶（PPO）的活性变化及抗病相关基因的表达量,并通过平皿对峙试验研究印度梨形孢对烟草疫霉菌生长的影响.结果表明,接种烟草疫霉菌后,根部有印度梨形孢定殖的烟草发病严重度要显著低于对照;接种烟草疫霉菌后第1～10 d,根部有印度梨形孢定殖的烟草叶片中防御酶PAL、POD和PPO活性高于对照,在第1d,PAL活性是对照烟草的3.99倍,在第2d,POD活性是对照烟草的1.5倍,在第4d,PPO活性是对照烟草的2.66倍;实时荧光定量PCR（Real-time quantitative PCR,qRT-PCR）结果显示,接种烟草疫霉菌后第6～96 h,根部有印度梨形孢定殖的烟草叶片中抗病相关基因PR1b、P450-2、hrs203J、NmIMSP和P450-1的表达量高于对照;在第12h,PR1b、P450-2、hrs203J的表达量分别是对照烟草的3.8、15.7和3.1倍,在第48 h,NmIMSP的表达量是对照烟草的2.6倍,在第72 h,P450-1的表达量是对照烟草的1.5倍;平皿对峙试验结果显示印度梨形孢对烟草疫霉菌的生长没有抑制、重寄生作用.研究结果表明,印度梨形孢可显著提高烟草对黑胫病的抗性,对黑胫病的抗性不是通过印度梨形孢分泌的抗菌物质实现的,是与烟草中抗病相关基因表达量的上升、防御酶活性的提高有关.本研究初步揭示了印度梨形孢诱导烟草抗黑胫病的相关机理,为进一步深入研究烟�Piriformospora indica, isolated from Indian Thar desert, s identified as a plant root endophytic fungus which plays an important role in inducing resistance against biotic and abiotic stresses. Recently, P. indica has been regarded as a fungal model to study the interaction between endophytic fungus and plants. In order to study the influence of P.indica on black shank resistance in Nicotiana tobacum, we analyzed the differences of the incidence, antioxidant enzyme activities, including phenylalnine ammonialyase （PAL）,peroxidase （POD） and polyphenol oxidasei（PPO）, and the expression levels of disease resistance-related genes in P.indica-colonized and non-colonized plants after Phytophthora parasitica var. nicotianae inoculation. We also studied whether P.indica influenced the growth of P. parasitica var. nicotianae by antibiosis assay. The results showed that： （1）The disease severity of P. indica-colonized N. tobacum was significantly lower than that of non-colonized ones; （2） After P. parasitica var. nicotianae inoculation from 1 to 10 days, the activities of PAL, POD and PPO in P. indica-colonized tobacco were significantly higher than those in non-colonized plants. P. indica-colonized plants showed 3.99-fold greater PAL activity in comparison with controls after P. parasitica var. nicotianae inoculation for 1 day. Meanwhile, compared with controls, POD and PPO activity in P. indica-colonized plants were elevated by 1.5- and 2.26-fold after infestation with P. parasitica var. nicotianae for 2 and 4 days, respectively; （3） Real-time quantitative PCR （qRT-PCR） results showed that the expression levels of disease resistance-related genes （PRlb, P450-2, hrs203J, GST, NmlMSP and P450-1） were up-regulated in P. indica-colonized N. tobacum after P. parasitica var. nicotianae inoculation at 6 to 96 h, respectively. The expression levels of PRlb, P450-2, hrs203J were up-regulated by 3.8, 15.7 and 3.1 folds in P. indica-colonized N. tobacum compared with controls after P. parasitica var.

关 键 词：内生真菌 烟草 黑胫病 防御酶 抗病相关基因 

分 类 号：S435.72[农业科学—农业昆虫与害虫防治]