Molecular characterization of the genome-wide transporter family and their responses to boron conditions in common wheat ( L.).

Boron (B) deficiency is an agricultural problem that causes significant yield losses in many countries. B transporters (s) are responsible for B uptake and distribution and play important roles in yield formation. A comprehensive analysis of the family members in common wheat is still lacking. In the present study, to clarify the molecular characterization and response to B status, genome-wide genes and expression patterns were investigated. Fourteen genes were identified in common wheat by a homology search. The corresponding phylogenetic tree indicated that 14 genes were separately classified into subfamilies of , , and . All genes had 12-14 extrons and 11-13 introns. Most proteins contained 10 conserved motifs, and motifs 1, 2, 3, 4, and 6 constituted the conserved bicarbonate (HCO ) domain. Fourteen genes were mapped on 13 chromosomes mainly distributed in the first, third, fifth, and seventh homologous groups. The promoters of genes consisted of phytohormones, light responses, and stress-related cis-elements. GO analysis indicated that genes were enriched in terms of transmembrane transport and ion homeostasis. genes showed diverse expression profiles in different tissues. The members of the subfamily showed high expression in grains, leaves, roots, stems, and spikes, but members of the subfamily were highly expressed only in spikes and grains. RT-qPCR indicated that , , and were induced by low B concentrations and had much higher expression in roots than in shoots. , , , , , , and were induced by low and high B concentrations and had high expression in roots and shoots. and were upregulated by low and high B concentrations, respectively, but had expression only in roots. Our results provide basic information on the family, which is beneficial for elucidating the functions of genes to overcome the problem of B deficiency.