Gene expression signatures of rice floral organs before and after pollination under heat and combined drought and heat stress

Floral organs are extremely sensitive to stress during anthesis and lead to severe yield loss. Rice anthers and pollinated pistils of two cultivars with contrasting tolerance to heat and drought stress under variable conditions, including control, heat, combined heat and drought stress, were used to explore gene expression pattern in male and female reproductive organs during anthesis under control and stress conditions. More gene regulation was induced by combined drought and heat stress than heat in anthers of both cultivars. N22 showed less regulation under combined stress than Moroberekan. The overlap of regulated genes between two cultivars was rather low, indicated the distinct molecular stress responses. We used whole genome microarrays to explore gene expression pattern and molecular mechanisms in male and female reproductive organs during anthesis under control and stress conditions in two rice cultivars, sought to identify the key transcripts that play roles in inducing heat and drought tolerance during reproduction in rice. Rice anthers and pollinated pistils from two cultivars N22 and Moroberekan at different conditions were collected for RNA extraction and hybridization on Affymetrix rice microarrays. We tried to explore temporal transcriptome changes and molecular mechanisms in male and female reproductive organs during anthesis under control, heat, or combined drought and heat stress in two contrasting rice cultivars.