Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, National Crop Gene Bank Building, Beijing 100081, China.
National Nanfan Research Institute, Chinese Academy of Agricultural Sciences, Sanya 572024, China.
Plant Cell. 2023 Aug 2;35(8):2773-2798. doi: 10.1093/plcell/koad118.
Rhizoctonia solani is a devastating soil-borne pathogen that seriously threatens the cultivation of economically important crops. Multiple strains with a very broad host range have been identified, but only 1 (AG1-IA, which causes rice sheath blight disease) has been examined in detail. Here, we analyzed AG4-HGI 3 originally isolated from Tartary buckwheat (Fagopyrum tataricum), but with a host range comparable to AG1-IA. Genome comparison reveals abundant pathogenicity genes in this strain. We used multiomic approaches to improve the efficiency of screening for disease resistance genes. Transcriptomes of the plant-fungi interaction identified differentially expressed genes associated with virulence in Rhizoctonia and resistance in Tartary buckwheat. Integration with jasmonate-mediated transcriptome and metabolome changes revealed a negative regulator of jasmonate signaling, cytochrome P450 (FtCYP94C1), as increasing disease resistance probably via accumulation of resistance-related flavonoids. The integration of resistance data for 320 Tartary buckwheat accessions identified a gene homolog to aspartic proteinase (FtASP), with peak expression following R. solani inoculation. FtASP exhibits no proteinase activity but functions as an antibacterial peptide that slows fungal growth. This work reveals a potential mechanism behind pathogen virulence and host resistance, which should accelerate the molecular breeding of resistant varieties in economically essential crops.
立枯丝核菌是一种严重威胁重要经济作物种植的土传病原真菌。已鉴定出多种宿主范围非常广泛的菌株，但仅对其中 1 种（引起水稻纹枯病的 AG1-IA）进行了详细研究。在这里，我们分析了最初从苦荞麦（Fagopyrum tataricum）中分离出的 AG4-HGI3，但其宿主范围与 AG1-IA 相当。基因组比较表明该菌株含有丰富的致病性基因。我们使用多组学方法来提高筛选抗病基因的效率。植物-真菌互作的转录组分析鉴定了与 Rhizoctonia 致病和苦荞麦抗性相关的差异表达基因。与茉莉酸介导的转录组和代谢组变化的整合揭示了茉莉酸信号的负调节剂，细胞色素 P450（FtCYP94C1），作为增加抗病性的可能途径是通过积累与抗性相关的类黄酮。对 320 份苦荞麦种质资源的抗性数据的整合，鉴定出与天冬氨酸蛋白酶（FtASP）基因同源的基因，该基因在接种立枯丝核菌后表达量最高。FtASP 不具有蛋白酶活性，但作为一种抗菌肽，可减缓真菌生长。这项工作揭示了病原菌致病和宿主抗性背后的潜在机制，这应该会加速经济作物中抗病品种的分子育种。
