ABSTRACT: The fungal pathogen Sclerotinia sclerotiorum infects a broad range of dicotyledonous plant species and is the causative agent of stem rot in Brassica napus. To elucidate the mechanisms underlying the defense response, we studied the patterns of gene expression in a partially resistant variety of ZhongYou 821 (ZY821) and a susceptible line from Westar over five time points, 6, 12, 24, 48, and 72 hours post-inoculation (hpi) using a B. napus oligonucleotide microarray. Maximum differential gene expression was observed at 48 hpi in both genotypes with ZY821 responding more quickly than Westar. Specific sets of genes exhibited higher levels of expression at the earlier stages of the infection (6-12 hpi), including genes encoding defense-associated proteins such as chitinases, glucanases, osmotins and lectins and genes encoding transcription factors belonging to the zinc finger, WRKY, AP2, and MYB classes. Genes encoding enzymes involved in JA, ethylene, and auxin synthesis were induced in both genotypes, as were those for gibberellin degradation. Changes in metabolic pathways affecting carbohydrate and energy metabolism appeared to be directed toward shuttling carbon reserves to the TCA cycle. Genes involved in glucosinolate and phenylpropanoid biosynthesis were highly up-regulated suggesting that secondary metabolites are also important components of the response to S. sclerotiorum in B. napus. Keywords: Time course, infected vs mock infected Time course experiment (6hr, 12 hr, 24 hr, 48 hr, 72 hrs), sclerotinia infected vs mock-infected. Biological replicates: 3, independently harvested. Technical replicates: 2, dye swapped within each time for each biological replicate (total 6 slides per time point) time after innoculation: 6 hours: zy 6h inf vs control rep1, zy 6h control vs inf rep1, zy 6h inf vs control rep2, zy 6h control vs inf rep2, zy 6h inf vs control rep3, zy 6h control vs inf rep3 time after innoculation: 12 hours: zy 12h inf vs control rep1, zy 12h control vs inf rep1, zy 12h inf vs control rep2, zy 12h control vs inf rep2, zy 12h inf vs control rep3, zy 12h control vs inf rep3 time after innoculation: 24 hours: zy 24h inf vs control rep1, zy 24h control vs inf rep1, zy 24h inf vs control rep2, zy 24h control vs inf rep2, zy 24h inf vs control rep3, zy 24h control vs inf rep3 time after innoculation: 48 hours: zy 48h inf vs control rep1, zy 48h control vs inf rep1, zy 48h inf vs control rep2, zy 48h control vs inf rep2, zy 48h inf vs control rep3, zy 48h control vs inf rep3 time after innoculation: 72 hours: zy 72h inf vs control rep1, zy 72h control vs inf rep1, zy 72h inf vs control rep2, zy 72h control vs inf rep2, zy 72h inf vs control rep3, zy 72h control vs inf rep3 biological replicate: zy 6h inf vs control rep1, zy 6h inf vs control rep2, zy 6h inf vs control rep3 biological replicate: zy 6h control vs inf rep1, zy 6h control vs inf rep2, zy 6h control vs inf rep3 technical replicate - labeled-extract: zy 6h inf vs control rep1, zy 6h control vs inf rep1 technical replicate - labeled-extract: zy 6h inf vs control rep2, zy 6h control vs inf rep2 technical replicate - labeled-extract: zy 6h inf vs control rep3, zy 6h control vs inf rep3 biological replicate: zy 12h inf vs control rep1, zy 12h inf vs control rep2, zy 12h inf vs control rep3 biological replicate: zy 12h control vs inf rep1, zy 12h control vs inf rep2, zy 12h control vs inf rep3 technical replicate - labeled-extract: zy 12h inf vs control rep1, zy 12h control vs inf rep1 technical replicate - labeled-extract: zy 12h inf vs control rep2, zy 12h control vs inf rep2 technical replicate - labeled-extract: zy 12h inf vs control rep3, zy 12h control vs inf rep3 biological replicate: zy 24h inf vs control rep1, zy 24h inf vs control rep2, zy 24h inf vs control rep3 biological replicate: zy 24h control vs inf rep1, zy 24h control vs inf rep2, zy 24h control vs inf rep3 technical replicate - labeled-extract: zy 24h inf vs control rep1, zy 24h control vs inf rep1 technical replicate - labeled-extract: zy 24h inf vs control rep2, zy 24h control vs inf rep2 technical replicate - labeled-extract: zy 24h inf vs control rep3, zy 24h control vs inf rep3 biological replicate: zy 48h inf vs control rep1, zy 48h inf vs control rep2, zy 48h inf vs control rep3 biological replicate: zy 48h control vs inf rep1, zy 48h control vs inf rep2, zy 48h control vs inf rep3 technical replicate - labeled-extract: zy 48h inf vs control rep1, zy 48h control vs inf rep1 technical replicate - labeled-extract: zy 48h inf vs control rep2, zy 48h control vs inf rep2 technical replicate - labeled-extract: zy 48h inf vs control rep3, zy 48h control vs inf rep3 biological replicate: zy 72h inf vs control rep1, zy 72h inf vs control rep2, zy 72h inf vs control rep3 biological replicate: zy 72h control vs inf rep1, zy 72h control vs inf rep2, zy 72h control vs inf rep3 technical replicate - labeled-extract: zy 72h inf vs control rep1, zy 72h control vs inf rep1 technical replicate - labeled-extract: zy 72h inf vs control rep2, zy 72h control vs inf rep2 technical replicate - labeled-extract: zy 72h inf vs control rep3, zy 72h control vs inf rep3
