小麦谷氨酸脱羧酶基因家族鉴定和表达特征分析OA

Gamma-aminobutyric acid(GABA)synthesis in plants is primarily catalyzed by glutamate decarboxylase(GAD),a key enzyme in GABA metabolism that is involved in regulating reactive oxy-gen species(ROS)accumulation and stress responses.In this study,genome-wide identification of the wheat TaGAD gene family members was performed,followed by analyses of their structural charac-teristics,miRNA targeting relationships,expression responses to exogenous hormones including IAA,MeJA,ABA,SA,and H2O2,as well as expression profiles of the GAD gene family induced by biological stress from stripe rust infection.The results showed that a total of 19 TaGAD genes were identified in the wheat genome,distributed across 7 chromosomes.Analysis of gene structure and conserved motifs revealed that most members of this family contained the Pyridoxal_deC conserved domain.miRNA target gene prediction suggested that the expression of TaGAD genes might be regu-lated at the translational level by miRNAs.Transcriptome analysis indicated that TaGAD9-3B,Ta-GAD11-3D,TaGAD4-2B,and TaGAD2-2A exhibited relatively high expression levels at different de-velopmental stages and in various tissues of wheat,and their expression was significantly altered un-der drought and high-temperature stresses.Quantitative real-time PCR analysis demonstrated that the transcript levels of TaGAD genes varied under exogenous substance treatments and stripe rust infec-tion.Among them,the expression of TaGAD4-2B was most significantly up-regulated by IAA induc-tion,with an increase of more than 300 fold,while TaGAD7-3A showed the highest expression change(24 fold up-regulation)under SA induction.Upon infection by the stripe rust physiological race CYR32,the expression levels of TaGAD15-4A and TaGAD19-4D were up-regulated more prominently,reaching 13 fold and 12 fold increases respectively,which were significantly higher than those of other family members.Through systematic identification,characteristic analysis,expression profiling and quantitative detection of stress responses of the wheat TaGAD gene family,this study lays a founda-tion for further in-depth research on the functions of TaGAD family members in wheat.