Study On Clone And Expression Of MsALMT1Gene In Medicago Sativa L

Al actived malate transporter of wheat (TaALMT1) is the first aluminum tolerancegene that has been linked to aluminum tolerant mechanisms in wheat. In this study,MsALMT1was cloned with primers based on homologous sequence alignment, then thegene expression pattern was investigated.The full length of MsALMT1cDNA is1347bp, encoding a protein containing448amino acid residues. The protein is predicted to contain6transmembrane domains.MsALMT1shares40%similarity with TaALMT1and46%similarity with AtALMT1.The tissue specificity of TaALMT1expression was studied. TaALMT1showedconstitutively expression in root and basal root. However, no expression was detected inleaves and stem. Furthermore, the gene were induced in response to both Al3+and H+stress. TaALMT1expression showed more sensitivity to Al3+than H+. Treated with thesame Al-dose, higher gene expression level was detected in Al sensitive cultivar “ZMNo.1” than that in tolerant cultivar “Apollo”. Cd2+and Cu2+also induced the expressionof MsALMT1which indicates MsALMT1expression is’t specifically responsive to theinduction of Al3+stress. In the Cd-dose experiment, gene expression was up-regulatedwhen increase the Cd-dose within certain degree. But gene expression is not positivecorrelated to the Cd-dose. These results suggest that MsALMT1is an aluminumactivated gene, that may be involved in mechanisms of partially aluminum resistant orresponse mechanism caused by heavy metal damage.