Genome-Wide Identification of the F-box Gene Family and Expression Analysis under Drought and Salt Stress in Barley

The F-box protein-encoding gene family plays an essential role in plant stress resistance.In present study,126 non-redundant F-box genes were identified in barley(Hordeum vulgare L.,Hv).The corresponding proteins contained 165–887 amino acid residues and all were amphiphilic,except 5 proteins.Phylogenetic analysis of F-box protein sequences in barley and stress-related F-box protein sequences in wheat and Arabidopsis thaliana(At)was used to classify barley F-box genes are divided into 9 subfamilies(A–I).A structure-based sequence alignment demonstrated that F-box proteins were highly conserved with a total of 10 conserved motifs.In total,124 F-box genes were unevenly distributed on 7 chromosomes;another 2 genes have not been anchored yet.The gene structure analysis revealed high variability in the number of exons and introns in F-box genes.Comprehensive analysis of expression profiles and phylogenetic tree analysis,a total of 12 F-box genes that may be related to stress tolerance in barley were screened.Of the 12 detected F-box genes,8 and 10 were upregulated after drought and salt stress treatments,respectively,using quantitative real-time polymerase chain reaction(qRT-PCR).This study is the first systematic analysis conducted on the F-box gene family in barley,which is of great importance for clarifying this family’s bioinformatic characteristics and elucidating its function in barley stress resistance.These results will serve as a theoretical reference for subsequent research on molecular regulation mechanisms,genetic breeding,and improvement.