水稻细条病是水稻生产中最严重的细菌性病害之一，至今未能有效控制该病害。近年来的研究表明小RNA在植物与病毒的互作中发挥重要作用，但植物与细菌互作中小RNA的研究报道不多，特别是水稻与细条病菌互作中小RNA的研究尚无报道。申请人前期工作筛选出一株典型Xoc GX01菌株和两个致病力丧失的突变株MAP35和36，GX01菌株基因组序列组装已基本完成。本课题拟采用分子生物学和功能基因组学研究技术通过比较分析GX01和MAP35,36侵染水稻前期水稻小RNA差异表达，结合转录组比较分析，鉴定与水稻细条病菌和水稻互作相关的水稻关键小RNA，对获得的候选小RNA进行功能鉴定，对候选小RNA的靶基因深入研究，阐明这些小RNA作用的分子机理，使人们对小RNA在植物病原细菌的致病过程中的作用有更进一步的认识。研究结果对人们将常规育种及分子标记辅助育种相结合,选育小RNA参与调节的水稻抗病品种具有指导作用

Bacterial leaf streak(BLS), caused by gram-negative bacterium Xanthomonas oryzae pv.oryzicola,Xoc, was one of the most serious diseases in rice cultivation. Due to the slow progress in the molecular basis of Xoc pathogenicity and host defence mechanisms involved, so far there is no feasible method to effectively and environmentally friendly control the disease. Recent studies show that small RNAs play an important role in the interactions between plants and viruses. However, few studies have reported the role of small RNAs in interactions between plants and bacteria, Especially, there is not any study to report the role of small RNAs in Oryza sativa and Xoc interactions. Our preliminary work has successfully isolated a typical Xoc GX01 strain and two nonpathogenic mutant strain,MAP35 and36. Genome sequence assembly of GX01 has nearly been completed. This study will use molecular biology and functional genomics technology such as RNA deep sequencing to identify small RNAs in Oryza sativa l. japonica nipponbare (Nipponbare) which is being infected by Xoc wild type and mutant respectively, and investigate the small RNA expression profiles of host plant. We will identify the key small RNAs involved in prophase of Nipponbare and Xoc interactions based on the differential expression profiles as well as the comparative analysis of RNA-Seq-based transcriptome results. On this basis, the biological functions of the identified key small RNAs and their target genes will be further studied systematically. In summary, this study will reveal the role of plant small RNAs in the plant-bacteria interaction. The study will provide new principles to guide disease-resistant rice-breeding based on small RNAs involved in the plants and bacteria interactions.