苹果SDH基因家族的鉴定及对非生物胁迫的响应OA

[Objective]The study aims to identify the sorbitol dehydrogenase(SDH)gene family in apples and analyze the response of SDH genes to abiotic stress,in order to elucidate the functions of SDH genes and provide references for improving apple stress resistance.[Method]The SDH gene sequences were initially screened using the apple genome database and the EMBL-EBI website.Subsequently,the physicochemical prop-erties and secondary structures of the encoded proteins of the apple SDH gene family were predicted.The phylo-genetic relationships,cis-acting elements,conserved domains,and expression patterns in different tissues of the apple SDH gene family were then analyzed.Finally,real-time quantitative PCR(RT-qPCR)was used to com-pare the expression levels of SDH genes under drought stress(10％ PEG),salt stress(200 mmol/L NaCl),and low-temperature stress(4 ℃)using normally grown apple plantlets as controls.[Result]Thirty sorbitol de-hydrogenase(SDH)genes were identified in apples and named MdSDH01 to MdSDH30 based on their chro-mosomal locations.The proteins encoded by these genes consisted of 324 to 430 amino acids,with isoelectric points ranging from 5.61 to 8.27 and molecular weights ranging from 34 647.76-46 931.21 ku.30 SDH genes were distributed across 9 chromosomes,and their secondary structures were primarily composed of random coils and α-helices.SDH were grouped into five subgroups:A,C,D,E and F.Ten conserved domains were found in the 30 SDH gene sequences,and the promoter regions contained response elements related to hormones,defense and stress,and adversity stress adaptability,and stress induction.MdSDH05,MdSDH07,MdSDH10,MdSDH14,MdSDH21,MdSDH26 and MdSDH28 were expressed in various tissues,while the remaining 23 SDH genes were not expressed.RT-qPCR results showed that,compared to the control,the expression of all 30 SDH genes was upregulated under drought stress.Under salt stress,the expression levels of MdSDH04,MdSDH05,MdSDH07 and MdSDH23 increased significantly.Under low-temperature stress,the expression of MdSDH30 was significantly upregulated.[Conclusion]SDH family members are obviously conservative,and their expression patterns in different tissues of apple are significantly different.Apple SDH gene family plays an important role in response to various stress conditions.