Stress-induced expression profiling of a calcium sensor, calcineurin B-like protein gene (SlCBL) in tomato

Abstract

SummaryThe calcineurin B-like protein (CBL) is a calcium sensor in plants. Here, we report on the functional characterisation of the SlCBL gene for a calcineurin B-like SOS3 protein from Solanum lycopersicum under abiotic stress conditions. Phylogenetic analysis, based on the deduced amino acid sequence derived from the SlCBL gene, showed sequence similarity to CBL proteins in rice (OsCBL7; 73%), Arabidopsis (AtCBL1, AtCBL4, and AtCBL9; 64%, 71%, and 65%, respectively), maize (ZmCBL4; 68%), and pea (PsCBL; 68%). The SlCBL gene exists as a single copy in the tomato genome. Northern blots showed that SlCBL is expressed differentially in different organs of tomato plants, with the highest levels of expression in roots and stems. Transcription levels of the SlCBL gene were stimulated in response to exogenous calcium, and by some abiotic stress elicitors. SlCBL gene expression was regulated by salt, drought, cold, and mechanical wounding. Gene expression also followed the abscisic acid-mediated signalling pathway.