Identification of MsHsp23 gene using annealing control primer system

Abstract

To identify potential candidates for acquiring stress tolerance, a new annealing control primer (ACP) system was used to identify the differentially expressed genes. Alfalfa (Medicago sativa L.) seedlings were exposed to various abiotic stresses such as cold (4A degrees C for 6 h), heat (42A degrees C for 6 h), salt (300 mM for 6 h), drought (withdrawing irrigation for 48 h), copper (500 mu M for 6 h), cadmium (500 mu M for 6 h), and arsenic (500 mu M for 6 h). Primer sets 41 and 93 were differentially expressed and identified as same sequence, which represents a mitochondrial small heat-shock protein encoding gene, MsHsp23. This band was markedly increased or induced in alfalfa under heat, salt, and arsenic stresses. Differential expression of MsHsp23 was further evaluated by Northern blot analysis. Temporal expression analysis showed that mRNA pool was altered as early as 1 h of treatment. Thus, differential accumulation of MsHsp23 under heat, salt, and arsenic stresses suggests its potential involvement in diverse abiotic stress tolerance, and thereby making a target for further molecular analysis.