Xie Xiaofang, Yang Xuansong, Lu Libin, Li Tong, Qin Mingyue, Guan Huazhong, Zheng Yan, Lan Tao, Wu Weiren
College of Life Sciences, Fujian Agriculture & Forestry University, Fuzhou, 350002, China.
Fujian Key Laboratory of Crop Breeding by Design, Fujian Agriculture & Forestry University, Fuzhou, 350002, China.
BMC Genomics. 2025 Aug 1;26(1):713. doi: 10.1186/s12864-025-11895-1.
DNA demethylases regulate the levels of genomic DNA methylation in plants. The demethylase REPRESSOR OF SILENCING 1 (ROS1) is a crucial factor for modulating gene expression in plant disease responses. Bacterial leaf streak (BLS), caused by Xanthomonas oryzae pv. Oryzicola (Xoc), is a highly destructive disease in rice. BLS resistance in rice is known to be quantitatively inherited, but the mechanisms by which DNA methylation controls BLS resistance remain poorly understood.
In this study, we knocked down OsROS1a expression in the rice variety Nipponbare using RNA interference (RNAi). The average BLS lesion length in the transgenic (T2) OsROS1a-RNAi (RS) lines was significantly reduced compared to that in wild-type Nipponbare plants (NP). Using whole-genome bisulfite sequencing (WGBS) and RNA-sequencing (RNA-seq), we analyzed the DNA methylations and transcriptomes of RS lines in comparison with NP at 0 (control), 5, 10, and 24 h post-inoculation with Xoc. A total of 1080 differentially expressed genes (DEGs) related to Xoc infection between the NP and RS lines were identified, which could be grouped into 8 clusters by K-means analysis. The DEGs in cluster 1 were enriched in the biological process related to defense response, response to stress, oxidation-reduction, etc. Integration of the methylome and transcriptome data revealed 112 overlapping differentially methylated and expressed genes (DMEGs). Gene Ontology (GO) analysis showed that the DMEGs were mainly involved in biological processes, such as metabolic process, cellular process, responses to stimulus, signaling, and immune system processes. KEGG pathway enrichment analysis revealed that these DMEGs were enriched in pathways related to glutathione metabolism, plant-pathogen interaction, cysteine and methionine, diterpenoid biosynthesis, photosynthesis, and starch and sucrose. Additionally, LOC_Os09g12660, encoding the glucose-1-phosphate adenylyl transferase large subunit, a chloroplast precursor involved in synthesizing activated glycosyl donor, showed strong potential to contribute to BLS resistance.
OsROS1a plays a crucial role in modulating rice resistance to bacterial leaf streak (BLS) caused by Xanthomonas oryzae pv. oryzicola (Xoc). These findings provide valuable insights into the role of OsROS1a in BLS resistance.
DNA去甲基化酶调节植物基因组DNA甲基化水平。沉默抑制因子1（ROS1）去甲基化酶是调节植物疾病反应中基因表达的关键因子。由水稻黄单胞菌稻生致病变种（Xoc）引起的细菌性条斑病（BLS）是水稻中一种极具破坏性的病害。已知水稻对BLS的抗性是数量遗传的，但DNA甲基化控制BLS抗性的机制仍知之甚少。
在本研究中，我们利用RNA干扰（RNAi）敲低了水稻品种日本晴中OsROS1a的表达。与野生型日本晴植株（NP）相比，转基因（T2）OsROS1a-RNAi（RS）系的平均BLS病斑长度显著缩短。利用全基因组亚硫酸氢盐测序（WGBS）和RNA测序（RNA-seq），我们分析了RS系与NP在接种Xoc后0（对照）、5、10和24小时的DNA甲基化和转录组。共鉴定出NP和RS系之间1080个与Xoc感染相关的差异表达基因（DEG），通过K均值分析可将其分为8个簇。簇1中的DEG在与防御反应、应激反应、氧化还原等相关的生物学过程中富集。甲基化组和转录组数据整合揭示了112个重叠的差异甲基化和表达基因（DMEG）。基因本体（GO）分析表明，DMEG主要参与代谢过程、细胞过程、对刺激的反应、信号传导和免疫系统过程等生物学过程。KEGG通路富集分析表明，这些DMEG在与谷胱甘肽代谢、植物-病原体相互作用、半胱氨酸和甲硫氨酸、二萜生物合成、光合作用以及淀粉和蔗糖相关的通路中富集。此外，编码葡萄糖-1-磷酸腺苷酰转移酶大亚基（一种参与合成活化糖基供体的叶绿体前体）的LOC_Os09g12660显示出对BLS抗性有很强的贡献潜力。
OsROS1a在调节水稻对水稻黄单胞菌稻生致病变种（Xoc）引起的细菌性条斑病（BLS）的抗性中起关键作用。这些发现为OsROS1a在BLS抗性中的作用提供了有价值的见解。
