Comparative Transcriptome Analysis Reveals the Biocontrol Mechanism of Bacillus velezensis F21 Against Fusarium Wilt on Watermelon
Comparative Transcriptome Analysis Reveals the Biocontrol Mechanism of Bacillus velezensis F21 Against Fusarium Wilt on Watermelon
复制标题
比较转录组分析揭示贝莱斯芽孢杆菌 F21 对西瓜枯萎病的生物防治机制
DOI：
10.3389/fmicb.2019.00652
复制
发表时间：
2019-04-03
影响因子：
5.2
通讯作者：
Guo, Jian-Hua
中科院分区：
文献类型：
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作者：
Jiang, Chun-Hao;Yao, Xie-Feng;Guo, Jian-Hua
西瓜（Citrullus lanatus）是世界上最重要的果树园艺作物之一。西瓜枯萎病是由西瓜枯萎病菌（Fusarium oxysporum f.）引起的一种土传病害，严重制约了西瓜的生产。白藓属在本研究中，我们鉴定了一个高效的PGPR菌株B。F21，可在西瓜生产上用于防治Fon。生防机理研究表明，B. Velezensis F21对Fon的生长和孢子萌发有抑制作用。而且，B。Velezensis F21还可通过提高植物防御相关基因的表达和CAT、POD、SOD等防御酶的活性，增强植物对Fon的基础免疫力。阐明调控B的详细机制。velezensis F21对西瓜枯萎病的生物防治，使用用B处理的西瓜植物根的比较转录组分析。Velezensis F21或无菌水单独接种和与Fon接种组合进行。转录组测序结果显示，在B成熟过程中，有近千个与成熟相关的差异表达基因（DEG）。velezensis F21触发对Fon的ISR（诱导的系统抗性）。此外，基因本体分类和京都基因与基因组百科全书（KEGG）途径富集结果表明，大量转录因子和植物抗病基因被激活，并通过实时荧光定量PCR（qRT-PCR）验证，不同处理的西瓜根系表达水平存在显著差异。此外，对MAPK信号通路和激素信号通路中的相关基因进行了分析，结果表明，B. Velezensis F21通过上述相关基因和植物激素信号因子增强植物对Fon的抗性。总之，这项研究大大扩展了转录组数据资源，并提出了B的分子框架。Velezensis F21诱导西瓜对Fon的系统抗性。此外，也为西瓜枯萎病的防治提供了一种有效的策略。
The watermelon (Citrullus lanatus) is one of the most important horticultural crops for fruit production worldwide. However, the production of watermelon is seriously restricted by one kind of soilborne disease, Fusarium wilt, which is caused by Fusarium oxysporum f. sp. niveum (Fon). In this study, we identified an efficient PGPR strain B. velezensis F21, which could be used in watermelon production for Fon control. The results of biocontrol mechanisms showed that B. velezensis F21 could suppress the growth and spore germination of Fon in vitro. Moreover, B. velezensis F21 could also enhance plant basal immunity to Fon by increasing the expression of plant defense related genes and activities of some defense enzymes, such as CAT, POD, and SOD. To elucidate the detailed mechanisms regulating B. velezensis F21 biocontrol of Fusarium wilt in watermelon, a comparative transcriptome analysis using watermelon plant roots treated with B. velezensis F21 or sterile water alone and in combination with Fon inoculation was conducted. The transcriptome sequencing results revealed almost one thousand ripening-related differentially expressed genes (DEGs) in the process of B. velezensis F21 triggering ISR (induced systemic resistance) to Fon. In addition, the Gene Ontology (GO) classification and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment indicated that numerous of transcription factors (TFs) and plant disease resistance genes were activated and validated by using quantitative real-time PCR (qRT-PCR), which showed significant differences in expression levels in the roots of watermelon with different treatments. In addition, genes involved in the MAPK signaling pathway and phytohormone signaling pathway were analyzed, and the results indicated that B. velezensis F21 could enhance plant disease resistance to Fon through the above related genes and phytohormone signal factors. Taken together, this study substantially expands transcriptome data resources and suggests a molecular framework for B. velezensis F21 inducing systemic resistance to Fon in watermelon. In addition, it also provides an effective strategy for the control of Fusarium wilt in watermelon.