Analysis of the function of the Arabidopsis DRL1 gene in Botrytis cinerea-induced transcriptome changes

To define how DRL1 regulates Botrytis cinerea-induced transcriptional changes at the genome level, we performed a microarray experiment on B. cinerea-infected drl1 and wild-type plants to identify genes that were differentially expressed between drl1 and the wild type. A total of 200 defense response genes were differentially expressed between drl1 and the wild type at six hours post-inoculation. These genes include 20 ethylene (ET) responsive genes, 23 jasmonic acid (JA)/ET responsive genes, 50 JA responsive genes, and 107 other defense genes. All ET and JA/ET responsive genes and majorities of JA responsive and other defense genes were down-regulated in the drl1 mutant. Among the down-regulated genes are a group of well-characterized defense genes, including ORA59, ERF1, WRKY33, SIB1, PAD3, GLIP1, and CYP79B2, which have been demonstrated to function in resistance to necrotrophic fungal pathogens, indicating that DLR1 may contribute to B. cinerea resistance by modulating the expression of these defense genes. Botrytis cinerea-induced gene expression in drl1 and wild-type leaf tissues was measured at 0, 6, and 48 hours post-inoculation. Three independent experiments were performed at each time point (0, 6, or 48 hours) using different plants for each experiment.