火龙果AHL基因家族全基因组鉴定及表达分析OA

[Objective]The members of the AHL gene family in pitaya were systematically identified to lay a foundation for elucidating their functions and regulatory mechanisms in growth and development of pitaya.[Method]Bioinformatics approaches were employed to analyze the gene structures,evolutionary relationships,and conserved motifs of the AHL gene family members,and RT-qPCR was further used to investi-gate their tissue-specific expression patterns.[Result]A total of 20 HpAHL genes were identified and distributed across 10 chromosomes,des-ignated as HpAHL1 to HpAHL20 according to their chromosomal locations.The HpAHL family exhibited diversity in gene structure(exon-in-tron and UTR organization),and all members contained typical AT-hook conserved motifs.Phylogenetic analysis classified the HpAHL into two clades(A and B)and revealed high homology with Arabidopsis AHL genes.Collinearity analysis further indicated gene duplication events within the HpAHL family,with stronger syntenic relationships to Arabidopsis than to rice.Tissue-specific expression profiling demonstrated dif-ferential expression of HpAHLs in roots,thorns,flower buds and stems.Among them,13 members including HpAHL1 were highly expressed in thorns,HpAHL14 and HpAHL17 showed relatively high expression in flower buds,and HpAHL11 was highly expressed in roots.Promoter se-quence analysis revealed that HpAHL promoters were enriched with cis-acting elements related to growth,development and stress responses.[Conclusion]The HpAHLs gene family is highly conserved,yet its members display significant physicochemical diversity.All proteins contain typical AT-hook and PPC/DUF296 domains,and their promoter regions harbour cis-elements associated with growth,development,hormone response and stress adaptation.The 20 genes are differentially expressed in roots,stems,thorns,flower buds,axillary buds,seeds,mature peri-carps and mature pulp.These findings provide essential sequence information and spatiotemporal expression profiles for the functional charac-terization of AHLs genes in pitaya.