Abstract
Male reproductive development in rice is highly organized and very sensitive to various environmental stresses including high temperature. Heat treatment at the young microspore stage induces pollen sterility. To investigate stress responsive mechanisms in rice male reproductive development, RNA was extracted from anthers at the early microspore stage, with or without heat treatment, and subjected to microarray analysis. We found that expression of several tapetum-specific genes was drastically reduced just after two days heat treatment. About 150 genes, which are expressed at high levels specifically in the mature anther under normal conditions, were identified as elevated expression just after four days heat treatment. However, expression of these genes was lower in the mature anther of heat-treated rice plants. These results suggest that heat treatment damaged function of tapetum and caused disruption of organized gene expression.