A Rice CaMBP Gene is Induced in Organ-Specific Manner by Both Chilling and Heat-Shock Treatments

A rice CaMBP gene, OsCaMBP (AB363406), was isolated from a chilling treated rice using the fluorescent differential display (FDD) screening method. Its cDNA sequence (2094 bp) contains an opening reading frame (ORF) encoding a 569 amino acids protein (63.2 kD). OsCaMBP has the typical structural features of the CaMBP family, including the conserved IQ calmodulin-binding motif at the N-terminus. Homology analysis revealed 38.25%–47.28% identities of OsCaMBP with other CaMBPs in plants. RT-PCR analysis showed that the expression of OsCaMBP was remarkably inducible under the chilling (8°C) and heat-shock (42°C) treatments. OsCaMBP was undetectable under the normal conditions, and induced under the chilling treatment for 1 h, as well as the heat-shock treatment for 15 min, suggesting that the gene plays important roles in the signaling pathway in rice under both chilling and heat-shock stresses.