Identification and Expression Analysis of Sulfate Transporter Genes Family and Function Analysis of GmSULTR3;1a from Soybean

Sulfate transporters (SULTRs) are essential for the transport and absorption of sulfate in plants and serve as critical transport proteins within the sulfur metabolism pathway, significantly influencing plant growth, development, and stress adaptation. A bioinformatics analysis of SULTR genes in soybean was performed, resulting in the identification and classification of twenty-eight putative GmSULTRs into four distinct groups. In this study, the characteristics of the 28 <i>GmSULTR</i> genes, including those involved in collinearity, gene structure, protein motifs, <i>cis</i>-elements, tissue expression patterns, and the response to abiotic stress and plant hormone treatments, were systematically analyzed. This study focused on conducting a preliminary functional analysis of the <i>GmSULTR3;1a</i> gene, wherein a high expression level of <i>GmSULTR3;1a</i> in the roots, stems, and leaves was induced by a sulfur deficiency and <i>GmSULTR3;1a</i> improved the salt tolerance. A further functional characterization revealed that <i>GmSULTR3;1a-</i>overexpressing soybean hairy roots had higher SO₄^2-, GSH, and methionine (Met) contents compared with the wild-type (WT) plant. These results demonstrate that the overexpression of <i>GmSULTR3;1a</i> may promote the sulfur assimilation metabolism and increase the content of sulfur-containing amino acids in plants.