Image_4_The ColRS-Regulated Membrane Protein Gene XAC1347 Is Involved in Copper Homeostasis and hrp Gene Expression in Xanthomonas citri subsp. citri.TIF

<p>Xanthomonas citri subsp. citri (Xcc) is the major causal agent of citrus canker disease. The XAC1347 gene, which encodes a conserved membrane protein in Xcc, is required for virulence during infection. However, the molecular events mediated by XAC1347 remain unclear. In this study, we reported that XAC1347 gene is positively regulated by two component regulatory system ColRS and required for type III secretion system function. A non-polar deletion mutant of the XAC1347 gene resulted in a Hrp minus phenotype in plants and reduced copper homeostasis. Real-time PCR experiments indicated that XAC1347 gene is induced by copper ions. The expression levels of representative genes from four hrp operons, including hrpB1, hrcV, hrpF, and hrpD6, were reduced in XAC1347 mutant, indicating that XAC1347 is involved hrp gene expression.</p

Bacterial growth in citrus tissue.

<p>Leaf planchets were cut from each infiltration area at 2-d intervals post inoculation to analyze bacterial growth. The values shown are means of three technical repeats with standard deviations.</p

Expression of cellulase genes in <i>X</i>. <i>citri</i> subsp. <i>citri</i>.

<p>(A) RT-PCR analysis of gene transcription in <i>X</i>. <i>citri</i> subsp. <i>citri</i> culturing in nutrient broth medium (NB) and growing in citrus. M, DL2000 marker. (B) Detection of BglC3 and EngXCA secretion using immunoblotting. Protein samples were analyzed by SDS-PAGE and immunoblotted using anti-c-Myc antibodies. TE, Total protein extract; SE, Culture supernatant.</p

Image_2_The ColRS-Regulated Membrane Protein Gene XAC1347 Is Involved in Copper Homeostasis and hrp Gene Expression in Xanthomonas citri subsp. citri.TIF

<p>Xanthomonas citri subsp. citri (Xcc) is the major causal agent of citrus canker disease. The XAC1347 gene, which encodes a conserved membrane protein in Xcc, is required for virulence during infection. However, the molecular events mediated by XAC1347 remain unclear. In this study, we reported that XAC1347 gene is positively regulated by two component regulatory system ColRS and required for type III secretion system function. A non-polar deletion mutant of the XAC1347 gene resulted in a Hrp minus phenotype in plants and reduced copper homeostasis. Real-time PCR experiments indicated that XAC1347 gene is induced by copper ions. The expression levels of representative genes from four hrp operons, including hrpB1, hrcV, hrpF, and hrpD6, were reduced in XAC1347 mutant, indicating that XAC1347 is involved hrp gene expression.</p

Table_2_The ColRS-Regulated Membrane Protein Gene XAC1347 Is Involved in Copper Homeostasis and hrp Gene Expression in Xanthomonas citri subsp. citri.DOCX

<p>Xanthomonas citri subsp. citri (Xcc) is the major causal agent of citrus canker disease. The XAC1347 gene, which encodes a conserved membrane protein in Xcc, is required for virulence during infection. However, the molecular events mediated by XAC1347 remain unclear. In this study, we reported that XAC1347 gene is positively regulated by two component regulatory system ColRS and required for type III secretion system function. A non-polar deletion mutant of the XAC1347 gene resulted in a Hrp minus phenotype in plants and reduced copper homeostasis. Real-time PCR experiments indicated that XAC1347 gene is induced by copper ions. The expression levels of representative genes from four hrp operons, including hrpB1, hrcV, hrpF, and hrpD6, were reduced in XAC1347 mutant, indicating that XAC1347 is involved hrp gene expression.</p

Image_3_The ColRS-Regulated Membrane Protein Gene XAC1347 Is Involved in Copper Homeostasis and hrp Gene Expression in Xanthomonas citri subsp. citri.TIF

<p>Xanthomonas citri subsp. citri (Xcc) is the major causal agent of citrus canker disease. The XAC1347 gene, which encodes a conserved membrane protein in Xcc, is required for virulence during infection. However, the molecular events mediated by XAC1347 remain unclear. In this study, we reported that XAC1347 gene is positively regulated by two component regulatory system ColRS and required for type III secretion system function. A non-polar deletion mutant of the XAC1347 gene resulted in a Hrp minus phenotype in plants and reduced copper homeostasis. Real-time PCR experiments indicated that XAC1347 gene is induced by copper ions. The expression levels of representative genes from four hrp operons, including hrpB1, hrcV, hrpF, and hrpD6, were reduced in XAC1347 mutant, indicating that XAC1347 is involved hrp gene expression.</p

Table_3_The ColRS-Regulated Membrane Protein Gene XAC1347 Is Involved in Copper Homeostasis and hrp Gene Expression in Xanthomonas citri subsp. citri.DOCX

<p>Xanthomonas citri subsp. citri (Xcc) is the major causal agent of citrus canker disease. The XAC1347 gene, which encodes a conserved membrane protein in Xcc, is required for virulence during infection. However, the molecular events mediated by XAC1347 remain unclear. In this study, we reported that XAC1347 gene is positively regulated by two component regulatory system ColRS and required for type III secretion system function. A non-polar deletion mutant of the XAC1347 gene resulted in a Hrp minus phenotype in plants and reduced copper homeostasis. Real-time PCR experiments indicated that XAC1347 gene is induced by copper ions. The expression levels of representative genes from four hrp operons, including hrpB1, hrcV, hrpF, and hrpD6, were reduced in XAC1347 mutant, indicating that XAC1347 is involved hrp gene expression.</p

Ectopic expression of nine cellulases in <i>Escherichia coli</i> BL21(DE3).

<p>(A) Degradation halos on Luria-Bertani plates supplemented with 0.5% carboxymethyl cellulose and 1.0 mM isopropyl-β-D-thiogalactopyranoside. (B) Diameters of the degradation halos. The tests were repeated three times; the data in the figure are the mean values. Two asterisks in the data column indicated significant differences at <i>P</i> = 0.01 by Student’s <i>t</i> test.</p

Table_1_The ColRS-Regulated Membrane Protein Gene XAC1347 Is Involved in Copper Homeostasis and hrp Gene Expression in Xanthomonas citri subsp. citri.DOCX

<p>Xanthomonas citri subsp. citri (Xcc) is the major causal agent of citrus canker disease. The XAC1347 gene, which encodes a conserved membrane protein in Xcc, is required for virulence during infection. However, the molecular events mediated by XAC1347 remain unclear. In this study, we reported that XAC1347 gene is positively regulated by two component regulatory system ColRS and required for type III secretion system function. A non-polar deletion mutant of the XAC1347 gene resulted in a Hrp minus phenotype in plants and reduced copper homeostasis. Real-time PCR experiments indicated that XAC1347 gene is induced by copper ions. The expression levels of representative genes from four hrp operons, including hrpB1, hrcV, hrpF, and hrpD6, were reduced in XAC1347 mutant, indicating that XAC1347 is involved hrp gene expression.</p

Additional file 1: Table S1. of Molecular study on the carAB operon reveals that carB gene is required for swimming and biofilm formation in Xanthomonas citri subsp. citri

Primers used in this study. (DOC 38 kb