苹果Ca2+/H+反向转运蛋白基因(MdCAX3-like)特征及其对非生物胁迫的响应OA

To investigate the characteristics of the MdCAX3-like gene encoding apple Ca2+/H+antiporter and its ex-pression patterns under abiotic stress,this study employed bioinformatics analysis and quantitative real-time PCR(qRT-PCR)to analyze the molecular characteristics of MdCAX3-like and its relative expression levels under salt,drought,low temperature,and gibberellic acid(GA3)treatments.The results show that the ORF of MdCAX3 gene is 1362 bp long,encoding 421 amino acid residues,located on chromosome 11;MdCAX3 protein contains a typical Na_Ca_ex domain,shows the highest homology with PbCAX3 protein and shares the closest affinity.It is a stable,acidic,hydrophilic protein with 11 transmembrane helices and abundant α-helix,functions as a transmembrane transporter protein,and is primarily localized to the vacuole.The promoter region contains multiple cis-acting ele-ments associated with light-induced response,stress responses,and hormone response.The fluorescence quantifi-cation results demonstrated that MdCAX3-like gene negatively regulates response to cold and drought stress and may participate in plant responses to salt stress and GA3 signaling.This study lays an important foundation for future in-depth analyses of MdCAX3-like genes functions in apple stress resistance and their regulatory mechanisms.