A time-course transcriptome study of hrpG and hrpX regulons in Xanthomonas axonopodis pv. citri

ABSTRACT: Xanthomonas axonopodis pv. citri (XAC) is the causal agent of citrus canker which is one of the most serious diseases of citrus. To understand the virulence mechanism of XAC, we designed and conducted genome-wide microarray analyses to characterize the regulons of HrpG and HrpX, which are critical for the pathogenicity of XAC. Our analyses revealed that the expression of 232 genes and 181 genes belonged to the HrpG and HrpX regulons, respectively. Totally, 123 genes were overlapped in the two regulons at any of the three time-points. Our results showed that HrpG and HrpX regulated all 25 T3SS genes, 22 T3SS effector genes, and 29 T2SS substrate genes. Our data showed that XAC regulates multiple cellular activities responding to the host environment, such as amino acid biosynthesis, oxidative phosphorylation, pentose-phosphate pathway, transport of sugar, iron and potassium, the phenolic compounds catabolism pathway (pcaQ) through HrpX and HrpG. We also identified 124 and 90 unknown genes controlled by HrpG and HrpX, respectively. Our data suggest that a cross-talk exists between HrpG and quorum sensing system in XAC. We also identified genes involved in chemotaxis and flagellar biosynthesis, production of extracellular enzymes, metabolic pathways, as well as signal transduction controlled by HrpG/HrpX. Our results suggest that HrpG and HrpX interplay with global signaling network and co-ordinate the expression of multiple virulence factors for modification and adaption of host environment during XAC infection. Two mutants and three time-points experiment. Four biological and dye-swap replicates of each strain per each time-point were used. Totally, there were three datasets of hrpG mutant: 1) hrpG mutant vs. wild type strain at time-point A; 2) hrpG mutant vs. wild type strain at time-point B; 3) hrpG mutant vs. wild type strain at time-point C. There are also three datasets of hrpX mutant: 1) hrpX mutant vs. wild type strain at time-point A; 2) hrpX mutant vs. wild type strain at time-point B; 3) hrpX mutant vs. wild type strain at time-point C.

ORGANISM(S): Xanthomonas axonopodis pv. citri str. 306

SUBMITTER: Yinping Guo 

PROVIDER: E-GEOD-24016 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress