A cDNA clone encoding an ABA-responsive protein HVA1, was isolated by differential screening from barley aleurone layers (Hong et al.), Expression of the HVA1 gene is shown to be developmentally regulated, organ specif ic, and ABA and stress-induced (Hong et al.). Transgenlc tobacco plants constitutively expressing HVA1 protein displayed a 4-day delay of leave wilting under drought conditions and a lower water content threshcdd (39% vs 47.6%) at the time point of first wilting. These data indicate that HVA1 protein may play a role in plant tolerance to drought A cDNA clone encoding an ABA-responsive protein HVA1, was isolated by differential screening from barley aleurone layers (Hong et al.), Expression of the HVA1 gene is shown to be developed specifically regulated, organ ic ic, and ABA and stress-induced ( Hong et al.). Transgenlc tobacco plants constitutively expressing HVA1 protein displayed a 4-day delay of leave wilting under drought conditions and a lower water content threshcdd (39% vs 47.6%) at the time point of first wilting. HVA1 protein may play a role in plant tolerance to drought