Abstract:

A gene named MdCBL3（MDP0000155124）was cloned from‘Gala’apple（Malus × domestica Borkh.）. The length of MdCBL3 was 852 bp. A phylogenetic tree analysis indicated that the Pyrus bretschneideri exhibited the highest sequence similarity to MdCBL3. The promoter’s cis-acting elements were analyzed and predicted using PlantCare Databases，analysis showed that the MdCBL3 promoter sequence included drought，low temperature，light，auxin，defense responsiveness etc. Construct expression vector of MdCBL3 and use Agrobacterium mediated method to infect apple callus and Arabidopsis seed. Semi RT-PCR indicated that MdCBL3 was genetically transformed into apple callus and Arabidopsis. Phenotypic analysis found that transgenic callus and Arabidopsis seedling grow better and have stronger resistance under NaCl stress compared with contrast. Demonstrated that overexpression of MdCBL3，heterogenous expression of MdCBL3 remarkably increased the tolerance of transgenic apple callus and Arabidopsis to high salinity. The study found that heterogenous expression of MdCBL3 in Arabidopsis enhenced the tolerance of drought and low temperature.

Key words: apple, MdCBL3, molecular clone, functional identification, salt stress