基于整合方法分析茶树响应病原真菌胁迫的共有模式

Common Pattern in Response to Pathogenic Fungal Stress of Tea Plants Based on Meta-analysis

摘要:

为探讨茶树（Camellia sinensis）对病菌胁迫的共有响应模式和抗病机制，运用生物信息学方法对多组RNA-seq数据进行提取、整合及功能富集，结合多种工具和数据库资源对主要调控分子及蛋白互作模块加以分析。结果表明，病原真菌胁迫下，茶树有较多细胞色素P450家族成员表达显著上调；类固醇和激素的代谢过程、苯丙烷合成途径被激活，有丝分裂细胞周期调控、DNA甲基化等生物过程及光合作用途径受到抑制；主要调控分子如转录因子WRKY和NAC、激酶RLK-Pelle和CAMK等以上调为主。差异表达的蛋白互作模块分析表明，有丝分裂周期调控、基于微管运动、淀粉和蔗糖代谢、细胞壁多糖合成、光合作用、类黄酮代谢模块明显下调，木质素合成和萜类生物合成模块上调；且模块之间可能存在互作。病菌胁迫激活的木质素和萜类合成途径的关键基因包括阿魏酸-5-羟基化酶基因F5H、过氧化物酶基因POD和萜类合成酶基因HMGR等。细胞色素P450基因可能在病菌胁迫中起关键作用，增强木质素和萜类物质的合成、削弱光合作用可能是茶树响应真菌胁迫的核心模式。

关键词:茶树;病原真菌;病菌胁迫;整合分析

Abstract:

To explore the common response mode and disease resistance mechanism of tea plants (Camellia sinensis) to pathogenic stress, bioinformatics methods were used to extract, integrate and function enrich of multiple sets of RNA-seq data, and the main regulatory molecules and protein interaction modules were analyzed by combining various tools and database resources. This results showed that the expression of cytochrome P450 family members in tea plant was significantly up-regulated under the fungal pathogen stress. The metabolic processes of steroid and hormone, and phenylpropanoid synthesis pathway were activated, and the biological processes, such as mitotic cell cycle regulation, DNA methylation and photosynthesis pathway were inhibited. The major regulatory molecules, such as WRKY and NAC transcription factors, the RLK-Pelle and CAMK family of kinases were mainly up-regulated. The differentially expressed protein interaction modules showed that the modules involved in mitotic cycle regulation, microtubule motion-based, starch and sucrose metabolism, cell wall polysaccharide synthesis, photosynthesis, flavonoid metabolism were down-regulated, while lignin synthesis and terpenoid biosynthesis were up-regulated. There may be interactions between modules. The key genes in lignin and terpenoid synthesis pathways activated by pathogen stress included ferulic acid-5-hydroxylase gene (F5H), peroxidase gene (POD) and terpenoid synthase gene HMGR. Cytochrome P450 gene might play a key role in fungus stress of tea plants. Enhancing the synthesis of lignin and terpenoids, and weakening photosynthesis might be the core modes of tea plants responding to fungus stress.

Key words:Tea plant;Fungal pathogen;Pathogenic fungi stress;Meta-analysis