摘 要

樟疫霉（Phytophthora cinnamomi）属于卵菌门疫霉属（Phytophthora），广泛分布于欧洲、美洲、东亚、南亚及大洋洲等地区，其寄主广泛，包括樟属植物在内的超过3000多种林木和农作物等。由该菌侵染樟属植物引起根部腐烂以及枝干溃疡等病害，对樟属植物造成毁灭性的破坏。樟疫霉已经成为林木病害防治的重要病原菌之一。卵菌基因组存在一类特殊的分泌蛋白，它们是从已鉴定的无毒基因的序列比对中被发现：一般为短蛋白，没有内含子，序列前端的信号肽下游，50-70位氨基酸左右，具有保守的RxLR-dEER元件。RxLR类（R，精氨酸；x，任何氨基酸；L，亮氨酸）效应分子在卵菌逃避植物识别以及卵菌进化过程中均起着重要作用。因RXLR-dEER与卵菌无毒基因具有类似的N端保守结构，因此将这类蛋白称作无毒基因同系(Avr homologs,Avh)基因。本研究借助重复比对（recursive BLAST）、隐马尔可夫（HMM）、跨膜结构预测等生物信息学方法，从樟疫霉中筛选出RXLR类效应分子，并对这些效应分子的进化关系和结构域进行分析，从而对后期研究效应分子的毒性功能和作用机制提供重要依据。

关键词：樟疫霉；效应分子；生物信息学

Biological information analysis of Phytophthora cinnamomi effectors

Abstract

Phytophthora cinnamomi belongs to the Oomycota Phytophthora genus,widely distributed in Europe,America,East Asia,South Asia and Oceania region,the broad host range,including Cinnamomum plants,including more than 3000 kinds of trees and crops and so on.Caused by root rot and stemcanker disease infected by the fungus genus Cinnamomum,destroy cinnamomum.Phytophthora cinnamomi has become one of the important pathogens of forest disease prevention and control.A special class of secreted proteins in the presence of oomycete genomes.They are from sequence alignment identified avirulence genes were found:generally short protein, no intron, downstream sequence front-end signal peptide,about50-70amino acids,with conservative RxLR-dEER element. RxLR class(R：arginine;X：any amino acid;L：leucine)effector molecules play an important role in the identification of eggs and the evolution of the eggs.Because of RXLR-dEER and oomycete avr genes with similar N terminal conserved,so will this kind of protein called avirulence genes homologous(AVR homologs,Avh)of genes.Repeat alignment(recursive blast),and hidden Markov models(HMM), cross membrane structure prediction and Bioinformatics Method by this study,from Phytophthora cinnamomi screened RXLR effector molecules,and on the effects of molecular evolutionary relationships and domain analysis was performed,and on later research investigate effector molecules of the toxicity function and mechanism of action to provide an important basis.

Key Words: phytophthora cinnamomi；Effector molecule；Biological information science

目 录

1 文献综述........................................................................................................................................1

1.1效应分子分类及研究进展......................................................................................................2

1.1.1 RxLR效应分子的转运机制.........................................................................................2

1.1.2 RxLR效应分子毒性机理的研究进展.........................................................................3

1.1.3 PiAvr3a操纵蛋白降解系统抑制植物的防卫反应......................................................5

1.1.4 PsAvh331通过干扰植物的MAPK信号途径抑制植物的抗病性..............................5

2 樟疫霉效应分子的生物学信息分析与转录测序样品的准备....................................................6

2.1 实验所用菌株 .......................................................................................................................6

2.2 樟疫霉刺槐变种（Phytophthora cinnamomi var. robiniae）序列资源..................................6

2.3培养基的制备..........................................................................................................................6

2.4樟疫霉刺槐变种（Phytophthora cinnamomi var. robiniae）RXLR效应分子结构域的查找........................................................................................................................................................7

2.5 樟疫霉刺槐变种（Phytophthora cinnamomi var. robiniae）RXLR效应分子同源性的比较........................................................................................................................................................7

2.5.1樟疫霉刺槐变种RXLR效应分子种内同源性................................................................7

2.5.2 RXLR效应分子变种间同源性........................................................................................8

2.5.3樟疫霉RXLR种间同源性................................................................................................8

2.6 樟疫霉刺槐变种RNA-Sequencing测序样品的准备...........................................................9

2.7 樟疫霉DNA提取...................................................................................................................9

2.8 樟疫霉RNA提取...................................................................................................................9

2.9 结果与分析...........................................................................................................................11