Functional analysis of Malus domestica MdWRKY23 gene in improving cold resistance
In order to investigate the effect of MdWRKY23 on cold resistance of Malus domestica and its mechanism, Malus domestica was used as the test material in this experiment. In this study, a 1452 bp WRKY family gene MdWRKY23 was obtained from Malus domestica, which encoded 483 amino acids. Subcellular localization studies found that MdWRKY23 protein was localized to the nucleus. The results of qRT-PCR showed that the expression level of MdWRKY23 gene was higher in plant roots, mature leaves and young leaves. Expression was low at the stemtip. Under cold treatment, the expression level of MdWRKY23 gene in young leaves and roots increased first and then decreased. Further studies showed that compared with the control plants, the MdWRKY23 gene overexpressing plants had stronger cold tolerance, and the expression of genes related to cold stress in the transgenic lines was significantly up-regulated. This study showed that MdWRKY23 gene could significantly improve plant cold resistance.