Isolation and Characterization of a Drought Inducible blt101 Homologous Gene from Rice

A novel cDNA from rice (Oryza sativa) subjected to a progressive drought stress was isolated and characterized. DNA polymorphisms were detected between drought-stressed and control rice plant using differential display. Subsequently, using the partial cDNA as probe, a full-length cDNA, designated as R1G1B, was isolated from the cDNA library constructed using the pooled cDNA from rice leaves with different levels of relative water content (RWC). Northern blot analysis demonstrated that the R1G1B transcript accumulated to a high level in rice leaves under mild drought conditions. Furthermore, at the DNA sequence level, the R1G1B showed a significant similarity to a family of blt101- homologous small proteins inducible in plants by chilling/low temperature, salt and drought stresses and was located on chromosome 5.