Identification and Expression Analysis of the Soybean Serine Acetyltransferase (SAT) Gene Family Under Salt Stress

Serine acetyltransferase (SAT) is a critical enzyme in the sulfur-assimilation pathway of cysteine, playing an essential role in numerous physiological functions in plants, particularly in their response to environmental stresses. However, the structural characteristics of the soybean <i>SAT</i> gene family remain poorly understood. Members of the soybean <i>SAT</i> gene family were identified using the Hidden Markov Model approach. Bioinformatics tools, such as ExPASy, PlantCARE, MEME, and TBtools-II, were employed to examine the physicochemical properties, cis-regulatory elements, conserved motifs, gene structures, and chromosomal positions of the <i>GmSAT</i> genes. RT-qPCR was conducted to evaluate the expression profiles of <i>GmSAT</i> genes under NaCl-induced stress, identifying genes likely involved in the salt-stress response. A total of ten <i>GmSAT</i> genes were identified in the soybean genome and grouped into three subfamilies. Genes within each subfamily shared notable structural similarities and conserved motifs. Analysis of cis-regulatory elements revealed that the promoters of these genes contain several elements linked to plant growth and stress-related responses. Expression patterns of <i>GmSAT</i> genes varied across different soybean tissues, with <i>GmSAT10</i> showing higher expression in roots, while <i>GmSAT1</i> and <i>GmSAT2</i> had lower expression in the same tissue. Following NaCl treatment, expression levels of seven <i>GmSAT</i> genes were significantly increased in the roots, indicating their potential involvement in the plant's adaptation to salt stress. <i>GmSAT</i> genes appear to play crucial roles in soybean's response to salt stress, offering insights that could aid in the development of salt-tolerant soybean varieties.