甘薯AUX/LAX基因家族鉴定和非生物胁迫下的表达分析OA

The precise regulation of auxin distribution by auxin transporters AUX/LAX(AUXIN RESISTANT1/LIKE AUX1)plays a crucial role in mediating plant growth,development,and responses to abiotic stresses.To characterize the AUX/LAX gene family members in sweetpotato(Ipomoea batatas)and explore their functional roles in stress adaptation,a genome-wide identification and systematic analysis of this gene family were performed in this study.A total of seven AUX/LAX members were identified,distributed across chromosomes 4,5,6,7,9 and 14.All encoded proteins contain the Aa_trans domain,share similar gene structures and conserved motifs,and are predicted to be membrane-localized with 4～11 transmembrane domains.Promoter analysis revealed that these AUX/LAX genes contain 33 types of cis-acting element associated with abiotic and biotic stress responses,hormone responses,and light responsiveness.Expression profiling in vegetable sweetpotato showed that IbAUX/LAX genes were significantly upregulated by eogenous auxin and exhibited distinct expression patterns under salt,drought,and heat stress.Among them,IbAUX2 and IbAUX3 were consistently downregulated under multiple abiotic stresses,whereas IbAUX5,IbAUX6,and IbAUX7 were significantly upregulated at 6 h,1 h and 1 h under drought and heat stress,respectively.Notably,IbAUX1 showed the most pronounced expression changes across all treatments.These findings suggest that AUX/LAX genes may play critical roles in the abiotic stress responses of vegetable sweetpotato.This study provides valuable insights into the functions of the AUX/LAX genes in mediating stress tolerance in vegetable sweetpotato,offering candidate gene resources for the genetic improvement of stress-resistant vegetable sweetpotato varieties.