Li Na, Huang Long, Liu Liping, Li Dazhi, Dai Suming, Deng Ziniu
Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization; Horticulture and Landscape College, Hunan Agricultural University, Changsha, Hunan, 410128, People's Republic of China,
Mol Biol Rep. 2014 Feb;41(2):967-75. doi: 10.1007/s11033-013-2941-4. Epub 2014 Jan 3.
Citrus canker disease, caused by Xanthomonas axonopodis pv. citri, affects almost all citrus species and cultivars and hascaused severe damage to the citrus industry worldwide. PthA is considered the main pathogenesis effector of the pathogen. This research aimed to temporally and spatially analyze the expression of the PthA protein of the bactrium during its culture, and then try to understand the relationship between the PthA expression levels and the pathogenicity. The relationship between the expression of PthA and the pathogenicity of X. axonopodis pv. citri was fully investigated by using SDS-PAGE, Western blot, ELISA and field inoculation, It was found that bacteria cultured for 36 h had the highest expression of PthA and showed the most virulent pathogenicity. The conservation duration of the pathogen isolates influenced their PthA expression and the pathogenicity, and negative relationship between the duration and the expression of PthA and pathogenicity. When the stored pathogen bacteria were cultured in liquid LB medium, they were able to regain activated, showing higher PthA expression level and enhanced pathogenicity, even though the activity was inferior, in terms of both PthA expression and pathogenicity, than the freshly isolated ones. Seven isolates from different citrus orchards displayed almost identical protein expression profiles. It could conclude that the expressions of PthA was positively related to pathogenicity.
柑橘溃疡病由柑橘溃疡病菌引起，几乎影响所有柑橘品种，给全球柑橘产业造成了严重损失。PthA被认为是该病原菌的主要致病效应因子。本研究旨在对该细菌培养过程中PthA蛋白的表达进行时空分析，进而了解PthA表达水平与致病性之间的关系。通过SDS-PAGE、Western印迹、ELISA和田间接种等方法，全面研究了柑橘溃疡病菌PthA的表达与致病性之间的关系。结果发现，培养36小时的细菌PthA表达量最高，致病性最强。病原菌分离株的保存时间影响其PthA表达和致病性，且保存时间与PthA表达及致病性呈负相关。当将保存的病原菌在液体LB培养基中培养时，它们能够恢复活性，表现出较高的PthA表达水平和增强的致病性，尽管在PthA表达和致病性方面，其活性均低于新分离的菌株。来自不同柑橘果园的7个分离株显示出几乎相同的蛋白质表达谱。可以得出结论，PthA的表达与致病性呈正相关。
