Gene expression analysis in wild-type and OsHOX24 rice overexpression line under control and drought stress conditions

Several homeobox genes belonging to HD-ZIP I subfamily are highly induced by drought stress at various developmental stages in rice. To analyze the role of a candidate HD-ZIP I subfamily member, OsHOX24, we constitutively overexpressed it in rice. The physiological analyses revealed that overexpression of OsHOX24 gene reduced drought stress tolerance in transgenic plants as compared to wild-type. We used microarrays to study the global effect of OsHOX24 overexpression in rice as compared to wild-type under control and drought stress condition. Three-weeks-old light-grown wild-type and transgenic rice seedlings grown under controlled conditions and those subjected to drought stress treatment were used for RNA extraction and hybridization on Affymetrix microarrays. Three biological replicates of each sample were used for microarray analysis. For drought stress treatment (DS), rice seedlings were dried for 3 h between folds of tissue paper at 28±1 degree C, in a culture room. The seedlings kept in water for 3 h, at 28±1 degree C, served as control (seedling).