Wu Guichun, Su Panpan, Wang Bo, Zhang Yuqiang, Qian Guoliang, Liu Fengquan
All authors: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China/Key Laboratory of Integrated Management of Crop Diseases and Pests (Nanjing Agricultural University), Ministry of Education, P.R. China; and sixth author: Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, P.R. China.
Phytopathology. 2017 Sep;107(9):1011-1021. doi: 10.1094/PHYTO-02-17-0053-R. Epub 2017 Jul 12.
Xanthomonas oryzae pv. oryzae, an economically important bacterium, causes a serious disease in rice production worldwide called bacterial leaf blight. How X. oryzae pv. oryzae infects rice and causes symptoms remains incompletely understood. Our earlier works demonstrated that the twin-arginine translocation (Tat) pathway plays an vital role in X. oryzae pv. oryzae fitness and virulence but the underlying mechanism is unknown. In this study, we used strain PXO99 as a working model, and identified 15 potential Tat-dependent translocation proteins (TDTP) by using comparative proteomics and bioinformatics analyses. Combining systematic mutagenesis, phenotypic characterization, and gene expression, we found that multiple TDTP play key roles in X. oryzae pv. oryzae adaption or virulence. In particular, four TDTP (PXO_02203, PXO_03477, PXO_02523, and PXO_02951) were involved in virulence, three TDTP (PXO_02203, PXO_03477, and PXO_02523) contributed to colonization in planta, one TDTP (PXO_02671) had a key role in attachment to leaf surface, four TDTP (PXO_02523, PXO_02951, PXO_03132, and PXO_03841) were involved in tolerance to multiple stresses, and two TDTP (PXO_02523 and PXO_02671) were required for full swarming motility. These findings suggest that multiple TDTP may have differential contributions to involvement of the Tat pathway in X. oryzae pv. oryzae adaption, physiology, and pathogenicity.
水稻白叶枯病菌是一种具有重要经济意义的细菌，在全球水稻生产中引发一种严重病害，称为细菌性条斑病。水稻白叶枯病菌如何侵染水稻并引发症状仍未完全清楚。我们早期的研究表明，双精氨酸转运（Tat）途径在水稻白叶枯病菌的适应性和毒力方面发挥着至关重要的作用，但其潜在机制尚不清楚。在本研究中，我们以PXO99菌株作为研究模型，通过比较蛋白质组学和生物信息学分析鉴定出15种潜在的Tat依赖性转运蛋白（TDTP）。结合系统诱变、表型特征分析和基因表达研究，我们发现多个TDTP在水稻白叶枯病菌的适应性或毒力中起关键作用。特别是，4种TDTP（PXO_02203、PXO_03477、PXO_02523和PXO_02951）参与毒力，3种TDTP（PXO_02203、PXO_03477和PXO_02523）有助于在植物体内定殖，1种TDTP（PXO_02671）在叶片表面附着中起关键作用，4种TDTP（PXO_02523、PXO_02951、PXO_03132和PXO_03841）参与多重胁迫耐受性，2种TDTP（PXO_02523和PXO_02671）是完全群体运动所必需的。这些发现表明，多个TDTP可能在Tat途径参与水稻白叶枯病菌的适应性、生理学和致病性方面具有不同的作用。
