Genome-wide Identification of AHK Family Members in Brassica juncea and Preliminary Exploration of Regulating Seed Weight Traits
In order to investigate the structural characteristics of Brassica juncea AHK family proteins and their regulatory functions related to seed weight traits,it employed bioinformatics methods to perform whole-genome iden-tification,physicochemical properties analysis,phylogenetic tree construction,protein structure analysis,promoter cis-elements analysis,and differential tissue expression profiling of the BjAHK family members.The main findings were as follows:a total of 19 BjAHK protein sequences were identified from the B.juncea genome,and phylogenetic analysis classified the BjAHK family members into four branches:G1(BjAHK2-BjAHK4),G2(BjAHK5),G3(BjAHK1),and G4(BjCKI1).Analysis of functional domains revealed the presence of six conserved motifs(Mo-tif1-Motif6)in BjAHK family members,corresponding to the HisKA,HATPase_c,and REC conserved domains.The N-terminal regions of BjAHK1-BjAHK4 and BjCKI1 proteins exhibited relatively conserved transmembrane domains,which might be associated with their transmembrane function.Differential tissue expression profiling re-vealed that the genes encoding cytokinin receptor proteins(BjAHK2-BjAHK4)were constitutively expressed genes,with the highest expression levels observed in root tissues.Through integration with existing transcriptomic data on seed weight traits in B.juncea,four candidate genes potentially involved in the regulation of seed weight traits were identified:BjA07.AHK3,BjB03.AHK3,BjA10.AHK5,and BjB05.AHK5.BjA07.AHK3 and BjB03.AHK3 might positively regulate seed development,while BjA10.AHK5 and BjB05.AHK5 might have the opposite effect.Based on the integration of gene family analysis and transcriptome result,it was inferred that BjAHK3 and BjAHK5 genes play an important role in the regulation of seed development in B.juncea.