We report here the nucleotide sequence of a rice (Oryza sativa cv. Akitakomachi) cDNA, a homologue of rab16A-D [5,10]. This cDNA clone, designated tab25, was obtained from a rice cDNA library [1] prepared from abscisic acid (ABA)treated suspension calli, by a simple subtractive method (K. Aguan et al., in preparation). The rice embryonic callus, originating from the scutellum, was cultured as described previously [4]. To eliminate any effect of light, the cultured cells were placed under continuous dim (200 lux) light. rab25 is 920 bp long and contains an open-reading frame of 687bp, which is translated into 228 amino acids corresponding to a protein of M~24722 (Fig. 1). At the nucleotide sequence level, tab25 shows 63.5?o, 60.2?o, 59.7?o and 51.0~o homology with barley dehydrin 9 [2], rice rab16 [5, 10], maize tab17 [8] and barley ABAinduced gene (pHVA 1-1) [ 3 ], respectively. Transcription of rab25 in rice calli was readily induced by either ABA (10 #M) treatment or high osmotic (0.5 M mannitol) stress (Fig. 2, lanes 3-6), as already reported by others [5, 10], but was rather repressed at low temperature even after 24 h of incubation compared with the control (25 ยฐC) (Fig. 2, lanes 1 and 2). Time-course analysis showed that transcription of rab25 was not in-