苹果Ca2+/H+反向转运蛋白基因(MdCAX5L-4)特征及其对非生物胁迫的响应OA

To investigate the characteristics of the apple Ca2+/H+antiporter MdCAX5L-4 gene and its expression patterns under abiotic stress,we analyzed the molecular properties and stress response using bioinformatics analysis and quantitative PCR.The results showed that the MdCAX5L-4 gene has a 1305-bp ORF encoding 434 amino acid residues and is located on chromosome 17.The MdCAX5L-4 protein contains a canonical Na_Ca_Ex domain and is an acidic transmembrane hydrophobic protein.Its secondary structure is predominantly α-helices,while the tertiary structure is entirely a monomer.The protein is primarily localized to the vacuole and shows the highest homology with PaCAX5-likeX1 and PpCAX5-likeX2,sharing a close phylogenetic relationship with European sweet cherry PaCAX5-like and Tokyo cherry blossom PyCAX5-likeX2.The MdCAX5L-4 gene positively regulates drought stress responses and may participate in apple responses to salt stress,cold stress and GA3 treatment.These results dem-onstrate that MdCAX5L-4 is involved in abiotic stress responses and associated signaling pathways.This study pro-vides a reference for further study on MdCAX5L-4 and the application of genetic engineering in apple genetic improvement.