Tobacco plants ectopically expressing the Ammopiptanthus mongolicus AmCBL1 gene display enhanced tolerance to multiple abiotic stresses

Ca2+ is a critical component in signal transduction pathways that lead to stress gene expression in higher plants and regulates a wide range of physiological processes. The calcineurin B-like protein (CBL) family represents a unique group of calcium sensors in plants, and plays a key role in decoding calcium transients. Here, a CBL1 homolog gene, AmCBL1 (NCBI accession no. AY902246), was isolated from Ammopiptanthus mongolicus (Maxim.) by reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). Quantitative real-time PCR (QRT-PCR) experiments showed that AmCBL1 was significantly induced by drought, high salinity, heat, and CaCl2 treatments in A. mongolicus seedlings. Subcellular localization analysis suggested that AmCBL1 is a plasma membrane-localized protein. Our results suggest that AmCBL1 is not only a positive regulator of salt response but also a positive regulator of temperature stresses in A. mongolicus.