普通菜豆镰孢菌枯萎病抗病相关基因PvMES1的克隆及其优异等位变异的挖掘

普通菜豆镰孢菌枯萎病是由尖镰孢菌菜豆专化型引起的一种典型土传病害，在全国各菜豆种植区均有发生，严重影响普通菜豆的产量和品质。水杨酸能够诱导植物产生系统抗病性反应，而水杨酸结合蛋白2是植物细胞内调控水杨酸水平的重要酯酶，该蛋白能够水解水杨酰甲酯，释放游离水杨酸。我们前期研究结果表明水杨酸能够诱导普通菜豆镰孢菌枯萎病的抗病性，因此研究水杨酸结合蛋白2在激发普通菜豆抗病反应过程中的作用成为本项目的关键问题，目前我们已经利用生物信息学方法搜索到普通菜豆中烟草水杨酸结合蛋白2的同源基因PvMES1。本项目拟以普通菜豆品种BRB-130为试材，克隆PvMES1基因，利用原核表达、基因过表达和RNA干扰等技术验证基因功能，通过PvMES1基因多态性与抗病性表型间的关联分析，挖掘PvMES1基因的优异等位变异，开发功能分子标记，分析PvMES1基因的单倍型，为普通菜豆镰孢菌枯萎病抗病分子育种提供理论基础。

Fusarium wilt caused by Fusarium oxysporum f. sp. phaseoli (Fop) is one of the most serious diseases of common bean (Phaseolus vulgaris L.), and is especially prevalent in China. It seriously affects the yield and quality of common bean. Salicylic acid (SA) is essential for the establishment of systemic acquired resistance (SAR) in plants. Salicylic acid-binding protein 2 (SABP2) is recognized as an important SA-regulated esterase in plants, SABP2’s methyl salicylate esterase (MES) activity is required in healthy systemic tissues of infected plants to release the active and free defense phytohormone SA from methyl salicylate (MeSA), which serves as a long-distance signal for SAR. The results of our previous study indicated that SA enhanced resistance to Fusarium wilt in common beans, therefore the role which SABP2 plays to stimulate systemic resistance in common beans is the key issue in this study. The putative ortholog to SABP2 in genomic database of common bean has been discovered in alignment with the SABP2 nucleotide sequence in tobacco by bioinformatic method, and designed with PvMES1. This study includes that PvMES1 gene is cloned from common bean cultivar BRB-130, and prokaryotic expression technology, overexpression and RNA interference technology are used to identify biofunctions of PvMES1, then the association analysis between PvMES1 polymorphism and resistant phenotypes against Fusarium wilt is performed to discover the elite allelic variation of PvMES1, develop the molecular markers and analyze the haplotypes based on PvMES1 sequence. The results can provide a theoretical basis for highly resistant cultivars breeding of common bean in the future.