关键词：
CfHNNI1;Cladosporium fulvum;过敏性坏死;非寄主抗病性;激发子
摘 要：
番茄叶霉菌(Cladosporium fulvum)CfHNNI1是一种寄主和非寄主抗病性的广谱激发子.但CfHNNI1cDNA序列是否为全长序列尚不明确.本研究构建了两个缺失不同长度5端序列的CfHNNI1序列结构,并研究了这些缺失型序列与坏死诱导功能之间的关系.研究结果表明,缺失包括ATG3在内的5端100bp序列,使缺失型CfHNNI1的翻译起始于ATG101,形成一个新的开读框,导致对番茄、烟草(Nicotiana tabacum)和N.clevelandii植株坏死诱导能力的完全丧失.而缺失所有在ATG273以前的4个ATG、长度为272bp的序列,但与ATG3处于同一密码框架中的缺失型CfHNNI1,丧失了诱发番茄、N.clevelandii以及N.paniculata产生坏死反应的能力,却仍能诱发N.tabacum,N.benthamiana,N.langsdorfii,N.glutinosa及N.solanifolia等5个Nicotiana种的植株产生明显坏死反应.这些结果说明,以ATG3为起始密码子的开读框是CfHNNI1真正开读框;5端272bp序列在诱导产生坏死反应中的作用因植物对象而异.
译 名：
Functional analysis of the 5’ prime sequence of CfHNNI1 gene of tomato leaf mould pathogen Cladosporium fulvum.
作 者：
ZHOU Xin, CAI Xin-zhong (Institute of Biotechnology, Zhejiang University, Hangzhou 310029, China)
关键词：
CfHNNI1; Cladosporium fulvum; hypersensitive response; nonhost resistance; elicitor
摘 要：
CfHNNI1 of the tomato leaf mould pathogen Cladosporium fulvum is a general elicitor of both host and nonhost resistance. However, it is still uncertain if the cloned CfHNNI1 cDNA sequence is full-length. In this study, two CfHNNI1 mutants with a deletion of 5’ sequence were constructed. The relationship between the deletion mutants and necrosis-inducing function was investigated. It was found that deletion of the 5’ 100 bp sequence, which renders translation of the mutant CfHNNI1 beginning from ATG101, leading to a new open reading frame (ORF), resulted in complete loss of the necrosis-inducing function in tomato, Nicotiana tabacum and N. clevelandii; while deletion of the 5’ 272 bp sequence including 4 ATGs before ATG273, which has the same ORF as ATG3, resulted in loss of the necrosis-inducing function in tomato, N. clevelandii and N. paniculata; but retained the function in 5 Nicotiana species including N. tabacum, N. benthamiana, N. langsdorfii, N. glutinosa and N. solanifolia. This result indicates that the ORF starting from ATG3 is the real one of CfHNNI1, and the role of the 5’ 272 bp sequence in inducing plant necrosis varies in different plant targets.
