Balone Tebogo, Pratama Ananda Nuryadi, Chansongkram Werapat, Boonsrangsom Thanita, Sujipuli Kawee, Ratanasut Kumrop
Department of Agricultural Science, Faculty of Agriculture Natural Resources and Environment, Naresuan University, Phitsanulok 65000, Thailand.
Center of Excellence in Research for Agricultural Biotechnology, Naresuan University, Phitsanulok 65000, Thailand.
Plant Pathol J. 2024 Oct;40(5):451-462. doi: 10.5423/PPJ.OA.04.2024.0070. Epub 2024 Oct 1.
Xanthomonas oryzae pv. oryzae (Xoo) is a pathogenic bacterium responsible for bacterial blight (BB) disease in rice, primarily mediated by the interaction between the plant and pathogen. The virulence mechanism involves the activation of the Sugars Will Eventually be Exported Transporter (SWEET) gene family in rice by transcription activator-like effectors derived from Xoo. The BB resistance gene xa5 has been identified as one of the most effective genes against Thai Xoo isolates, but xa5-mediated resistance-breaking Xoo strains have emerged. This study aimed to develop a single nucleotide polymorphism (SNP) marker for precise identification of xa5-mediated resistance-breaking Xoo. Comparative genomics of Thai Xoo isolates Xoo16PK001 and Xoo16PK002, which were incompatible and compatible with rice variety IRBB5 carrying xa5, respectively, identified eight SNP positions for the development of an SNP marker. The SNP marker XooE6 yields a specific 1,143 bp PCR product unique to Xoo16PK002. Screening 61 Thai isolates using XooE6 identified two positives: Xoo20PL010 and Xoo20UT002. Inoculation tests on rice varieties IRBB5 and IRBB13 demonstrated compatibility with IRBB5 and incompatibility with IRBB13, which bears Xa5 and xa13. Xoo16PK001 (XooE6-negative) showed different virulence. Inoculation on IRBB21 harboring Xa5, Xa13, and Xa21 resulted in partial resistance to both XooE6-positive and -negative strains. XooE6-positive strains up-regulated SWEET11 and suppressed SWEET14 in IRBB5, while Xoo16PK001 slightly induced SWEET11 but activated SWEET14 in IRBB13. This highlights the potential of XooE6 to identify xa5-mediated resistance-breaking Xoo strains and elucidate their pathogenic mechanisms through the upregulation of SWEET11.
水稻白叶枯病菌（Xanthomonas oryzae pv. oryzae，Xoo）是一种导致水稻白叶枯病（BB）的致病细菌，主要通过植物与病原体之间的相互作用介导。其致病机制涉及Xoo来源的转录激活样效应子激活水稻中的糖最终输出转运体（SWEET）基因家族。白叶枯病抗性基因xa5已被确定为针对泰国Xoo分离株最有效的基因之一，但已出现了能突破xa5介导抗性的Xoo菌株。本研究旨在开发一种单核苷酸多态性（SNP）标记，用于精确鉴定能突破xa5介导抗性的Xoo。对分别与携带xa5的水稻品种IRBB5不亲和及亲和的泰国Xoo分离株Xoo16PK001和Xoo16PK002进行比较基因组学分析，确定了8个SNP位点用于开发SNP标记。SNP标记XooE6产生一个1143 bp的特异性PCR产物，该产物是Xoo16PK002特有的。使用XooE6对61个泰国分离株进行筛选，鉴定出两个阳性菌株：Xoo20PL010和Xoo20UT002。对水稻品种IRBB5和IRBB13进行接种试验，结果表明它们与IRBB5亲和，与携带Xa5和xa13的IRBB13不亲和。Xoo16PK001（XooE6阴性）表现出不同的毒力。对携带Xa5、Xa13和Xa21的IRBB21进行接种，结果显示其对XooE6阳性和阴性菌株均表现出部分抗性。XooE6阳性菌株上调了IRBB5中的SWEET11并抑制了SWEET14，而Xoo16PK001在IRBB13中轻微诱导了SWEET11但激活了SWEET14。这突出了XooE6在鉴定能突破xa5介导抗性的Xoo菌株以及通过上调SWEET11阐明其致病机制方面的潜力。
