苹果B型细胞分裂素响应因子MdARR11对干旱胁迫的抗性分析OACSTPCD

B-type ARRs play an important role as positive response factors for cytokinins in plant growth and development.In order to explore the function of ARR11 in response to drought stress in apple,in this study Gala 3 apple(Malus domestica Borkh.cv Gala 3)was used as the test material and the B type cytokinin response factor gene MdARR11 was obtained using PCR amplification technology.The sequence was 2 248 bp in length and encodes 613 amino acids.It contains a type-B REC domain and a MYB like DNA binding domain at the C-terminus.Tissue-specific expression analysis showed that the gene had the highest expression level in the stem.The results of quantitative real-time PCR(qRT-PCR)analysis showed that drought stress inhibited the expression of MdARR11.To further validate the function of MdARR11 under drought stress,MdARR11-overexpressed apple calli was obtained.Wild type and overexpression of calli were treated with 6%,PEG6000 to simulate drought stress,the growth rate,size,and fresh weight,relative conductivity,the malondialdehyde(MDA)and proline(Pro),the accumulation of soluble protein and superoxide dismutase(SOD),peroxidase(POD),catalase(CAT)activity in calli were analyzed.The results showed that overexpression of MdARR11 increased the degree of lipid membrane peroxidation in callus cell membranes,decreased the accumulation of osmoregulation substances,and reduced antioxidant enzyme activity.In summary,MdARR11 reduced the tolerance of apple callus to drought stress.This study lays a foundation for further exploring the biological function and mechanism of action of the MdARR11 gene.