title: The relationship between PthA expression and the pathogenicity of Xanthomonas axonopodis pv. citri.
abstract: 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.
authors.affiliation: 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, 1112lina@163.com.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Long
authors.initials: L
authors.lastname: Huang
authors.forename: Liping
authors.initials: L
authors.lastname: Liu
authors.forename: Dazhi
authors.initials: D
authors.lastname: Li
authors.forename: Suming
authors.initials: S
authors.lastname: Dai
authors.forename: Ziniu
authors.initials: Z
authors.lastname: Deng
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D002957:Citrus / Q000235:genetics / Q000382:microbiology*; D015964:Gene Expression Regulation, Bacterial; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D000071336:Transcription Activator-Like Effectors; D053532:Xanthomonas axonopodis / Q000235:genetics* / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; C077723:PthA protein, Xanthomonas campestris; D000071336:Transcription Activator-Like Effectors