Comprehensive analysis of the gene family in tobacco and functional characterization of involvement in amino acids homeostasis.

Amino acids are vital nitrogen (N) sources for plant growth, development, and yield. The uptake and translocation of amino acids are mediated by amino acid transporters (AATs). The AATs family including lysine-histidine transporters (LHTs), amino acid permeases (AAPs), and proline transporters (ProTs) subfamilies have been identified in various plants. However, little is known about these genes in tobacco. In this study, we identified 23 genes, the important members of AATs, in the tobacco genome. The gene structure, phylogenetic tree, transmembrane helices, chromosomal distribution, -regulatory elements, and expression profiles of genes were systematically analyzed. Phylogenetic analysis divided the 23 genes into two conserved subgroups. Expression profiles confirmed that the genes were differentially expressed in various tissues, indicating their potential roles in tobacco growth and development. -elements analysis of promoters and expression patterns after stress treatments suggested that genes probable participate in abiotic stress responses of tobacco. In addition, Knock out and overexpression of changed the amino acids homeostasis in the transgenic plants, the contents of amino acids were significantly decreased in overexpression plants than wild-type. The results from this study provide important information for further studies on the molecular functions of the genes.