The gpsX gene encoding a glycosyltransferase is important for polysaccharide production and required for full virulence in Xanthomonas citri subsp. citri

Table 5 Comparison of virulence gene expression in the wild type and the gpsX mutant cultured in XVM2 medium by QRT-PCR ^a

Gene	locus_tag	Function of protein product	ΔΔC_T± SD^b	Fold change ± SD ^c	P ^d
gumB	XAC2585	EPS xanthan biosynthesis	0.2665 ± 0.1912	0.8314 ± 0.1102	0.0524
rfbC	XAC3598	LPS O-antigen biosynthesis	-0.2018 ± 0.1467	0.8695 ± 0.0841	0.0621
katE	XAC1211	Monofunctional catalase	0.0758 ± 0.1346	0.9485 ± 0.0871	0.4407
pthA	NS ^e	TTSS effector	-0.1703 ± 0.2407	1.1253 ± 0.1845	0.3128
hrpX	XAC1266	TTSS regulator	0.2578 ± 0.1638	0.8364 ± 0.0997	0.2442
hrcV	XAC0405	TTSS component	0.1828 ± 0.1348	0.8811 ± 0.0832	0.1119

^a Both 16S rRNA and gyrA genes were used as endogenous controls in the QRT-PCR experiments and similar results were obtained when the data were normalized against the two genes respectively. Only the data obtained with 16S rRNA gene as control were shown.
^b The mean ΔΔC_T was determined using four biological repeats. The experiment was repeated two times with similar results. Data from one experiment are shown.
^c The expression change (mutant/wild type) in mutant 223 G4 (gpsX-) was calculated using 2^-ΔΔCT.
^dP value, analyzed by Student's t -test. Values are significantly different when P is < 0.05.
^e No specific locus_tag. This represents the gene expression of pthA1, pthA2, pthA3 and pthA4.

ISSN: 1471-2180