Figure 5

Expression levels of potential targets of PthA4. Expression levels of DIOX, CP, 14-3-3 (1433), CCNBS1 and SIP1 (A), or LOB1 and LOB2 (B), in sweet orange leaves infiltrated with Xc or its mutant derivative lacking pthA4 (pthA4-deletion mutant), 72 h post-inoculation, relative to water-infiltrated leaves. All target genes were induced by Xc and pthA4-deletion mutant, relative to water infiltration; however, the expression levels of most genes, including DIOX, SIP1, LOB1 and LOB2, were significantly lower in the leaves infiltrated with the pthA4 mutant, suggesting a role of PthA4 in gene activation. The expression levels are the mean of three independent biological replicates. The error bars denote standard deviations whereas asterisks indicate statistically significant differences (p < 0.05) between the mRNA levels found in the leaves infiltrated with the pthA4 mutant, relative to the wild type X. citri.