‘桂蕉9号’抗香蕉枯萎病基因挖掘与功能鉴定

Fusarium wilt of banana, caused by Fusarium oxysporum f. sp. cubense (Foc 4), is a destructive disease of banana, which cause huge economic losses. There is no completely effective method to control Fusarium wilt disease so far. Therefore, the best and most effective control measure is to develop wilt-resistant banana cultivars by molecular breeding. It's also the inevitable trend of the banana industry. So we propose to compare the transcriptome profiles of the Cavendish banana‘Williams’and ‘Guijiao 9’inoculated with F. oxysporum f. sp. cubense tropical race 4 (Foc TR4) strain‘J-2’by RNA-seq analysis. The signaling pathways and expression patterns of differentially expressed genes will be screened by bioinformatic analysis. The resistance-related functional genes will be selected based on the annotation information, and then the full-length sequences of the candidate genes will be cloned. Next, transgenic approaches will be performed to validate the function of candidate genes. The outcome of this project will provide us solid knowledge to understand the mechanism of disease resistance of Fusarium wilt. Success of this project will provide guidance for large-scale screening of banana cultivar with resistance genes, and pave the way for developing new strategies for Fusarium wilt control and developing new wilt-resistant banana cultivars.

由尖孢镰刀菌古巴专化型引起的香蕉枯萎病是香蕉生产中的毁灭性病害，目前尚无有效防控措施。利用生物技术手段培育抗病品种是香蕉产业发展的必然趋势，也是最根本的防病措施。本项目以广西主栽香蕉品种‘Williams’（感）和‘桂蕉9号’（抗）为寄主材料，以枯萎病菌4号生理小种热带型（Foc TR4）强毒力菌株‘J-2’为病原菌，通过转录组测序、生物信息学分析等方法，研究抗、感品种的基因表达差异，明确差异表达基因所在的信号通路及表达调控模式，根据注释信息筛选抗病相关的功能基因并克隆目的基因全长序列，通过遗传转化对候选抗性基因进行功能验证。研究结果对揭示抗性品种的防御机制具有重要意义，为利用分子手段大规模、有目的地筛选含抗病基因的香蕉变异株系提供理论指导，也为枯萎病防治及抗病品种的培育提供新的策略和靶标。

由尖孢镰刀菌古巴专化型引起的香蕉枯萎病是香蕉生产中的毁灭性病害，目前尚无有效防控措施。利用生物技术手段培育抗病品种是香蕉产业发展的必然趋势，也是最根本的防病措施。本项目在已完成转录组测序的基础上，对获得的高质量数据进行生物信息学分析。通过转录组测序分析，筛选了‘桂蕉9号’（抗）和‘Williams’（感）香蕉受枯萎病菌4号生理小种热带型菌株（Foc-TR4）侵染后的显著差异表达基因，并进行了代谢通路分析。从‘桂蕉9号’抗病品种中获得6776个差异表达基因，其中与抗病密切相关基因49个。重点分析了防御反应、植物-病原菌互作、转录、植物激素合成与信号传导等抗病相关代谢通路的差异表达基因。NB-LRR蛋白、钙调蛋白和苯丙烷类合成基因等这些与防御反应相关的基因在桂蕉9号中显著上调表达。根据香蕉的参考基因组序列，设计引物，克隆目标抗病相关基因。对克隆的MaWRKY28、MaDRR206等基因进行了功能验证。结果表明这些基因在香蕉抗枯萎病菌侵染中参与了抗病相关过程。综上可知，植物激素调节和防御反应激活在介导‘桂蕉9号’抗病性中发挥了关键作用。项目研究结果为利用分子手段大规模、有目的地筛选含抗病基因的香蕉变异株系提供理论指导，也为枯萎病防治及抗病品种的培育提供新的策略和靶标。