Analysis of Colletotrichum orbiculare whi2Δ mutant infection of Cucumis sativus at 4hpi

Colletotrichum orbiculare Whi2, yeast stress response Whi2 homolog, is involved in switch from biotrophic to necrotrophic stage. To elucidate downstream genes regulated by Co Whi2, we have conducted DNA microarray. About 3100 genes were up or down regulated in the Co whi2Δ mutant compared with the wild-type. In particularly, 44 genes among up-regulated 58 genes in the Co whi2Δ mutant are ribosomal protein related gene. Eukaryote is widely conserved TOR (Target Of Rapamycin) which is known to regulator of ribosomal gene expression. To elucidate whether up-regulated ribosomal genes in the Co whi2Δ mutant are regulated by TOR activity, we have conducted DNA microarray in the Co whi2Δ mutant treated with rapamycin inhibiting TOR activity. The enormous ribosomal gene expression in the Co whi2Δ mutant treated with the rapamycin is lower than that without rapamycin treatment. In gene expression of the Co whi2Δ mutant, the wild-type and the Co whi2Δ mutant infecting on cucumber cotyledons were assessed at 4 hours post-inoculation. In gene expression of the Co whi2Δ mutant with rapamycin treatment, Co whi2Δ mutant treated with 100nM rapamycin and Co whi2Δ mutant without rapamycin treatment infecting on cucumber cotyledons were assesed at 4 hours post-inoculation. Four replication were performed for each experiments.