Expression profiles of pea pathogenicity (PEP) genes in vivo and in vitro, characterization of the flanking regions of the PEP cluster and evidence that the PEP cluster region resulted from horizontal gene transfer in the fungal pathogen Nectria haematococca
Expression profiles of pea pathogenicity (PEP) genes in vivo and in vitro, characterization of the flanking regions of the PEP cluster and evidence that the PEP cluster region resulted from horizontal gene transfer in the fungal pathogen Nectria haematococca
复制标题
豌豆致病性 (PEP) 基因的体内和体外表达谱、PEP 簇侧翼区域的特征以及 PEP 簇区域由真菌病原体 Nectria haematococca 中水平基因转移引起的证据
DOI：
10.1007/s00294-003-0428-x
复制
发表时间：
2003
期刊：
影响因子：
2.5
通讯作者：
H. Vanetten
中科院分区：
文献类型：
--
作者：
Xiaoguang Liu;M. Inlow;H. Vanetten
摘要豌豆致病性基因（PEP 1，PEP 2，PDA 1，PEP 5）位于一条1.6Mb的条件染色体上。研究确定，PDA 1的表达在感染的豌豆组织中和体外都由植物抗毒素pisatin诱导。本研究报告使用实时定量RT-PCR监测每个PEP基因和PDA 1的表达。在培养物中活跃生长的菌丝体中，PEP 1、PEP 5和PDA 1的mRNA水平非常低，PEP 2转录物检测不到。在植物中，PDA 1和PEP 2被强烈诱导，而PEP 1和PEP 5被中度诱导。饥饿使PEP 1、PDA 1和PEP 5的表达略有增加，而PEP 2的表达仍然检测不到。在培养物中暴露于pisatin刺激PDA 1和每个PEP基因的表达达到与植物中发生的相似水平。此外，所有四个致病性基因在植物体内和体外表现出相似的时间模式的表达，与豌豆毒蛋白在豌豆发病过程中对这些基因的协调调节一致。在PEP簇的侧翼区域，鉴定了六个开放阅读框（ORF），并且所有ORF在豌豆感染期间表达。比较这些ORF和CD染色体的7个额外基因的密码子偏好与来自其他染色体的21个基因的密码子偏好，发现存在与基因来源相关的密码子偏好。这种密码子偏好性的差异与CD染色体上的基因与正常染色体上的基因具有不同起源的假设一致，表明水平基因转移可能在N.红球菌属
Abstract A cluster of pathogenicity genes (PEP1, PEP2, PDA1, PEP5), termed the pea pathogenicity (PEP) cluster and located on a 1.6-Mb conditionally dispensable (CD) chromosome, was identified in the fungal pathogen Nectria haematococca. Studies determined that the expression of PDA1 is induced in both infected pea tissues and in vitro by the phytoalexin pisatin. The present study reports the use of real-time quantitative RT-PCR to monitor the expression of each PEP gene and PDA1. In mycelia actively growing in culture, the mRNA levels of PEP1, PEP5 and PDA1 were very low and the PEP2 transcript was undetectable. In planta, PDA1 and PEP2 were strongly induced, while PEP1 and PEP5 were moderately induced. Starvation slightly enhanced the expression of PEP1, PDA1 and PEP5, while the expression of PEP2 remained undetectable. Exposure to pisatin in culture stimulated the expression of PDA1 and each PEP gene to a similar level as occurred in planta. In addition, all four pathogenicity genes displayed similar temporal patterns of expression in planta and in vitro, consistent with a coordinated regulation of these genes by pisatin during pea pathogenesis. In the flanking regions of the PEP cluster, six open reading frames (ORFs) were identified and all were expressed during infection of pea. Comparison of the codon preferences of these ORFs and seven additional genes from CD chromosomes with the codon preferences of 21 genes from other chromosomes revealed there is a codon bias that correlates with the source of the genes. This difference in codon bias is consistent with the hypothesis that genes on the CD chromosome have a different origin from genes of normal chromosomes, suggesting that horizontal gene transfer may have played a role in the evolution of pathogenesis in N. haematococca.
影响因子：
56.9
作者：
MILLER, JF;MEKALANOS, JJ;FALKOW, S
通讯作者：
FALKOW, S