Amino acid transporter GmAAP6-like contributes to seed quality and responds to jasmonic acid pathway under MSX toxicity stress

Amino acid transporters participate in the transport and distribution of amino acids in plants and are vital for plant growth and development. Despite their importance, few works have investigated the functions of amino acid permeases (AAP) amino acid transporters in soybean. In this study, we re-identified the AAP family genes in soybean using a new public genome database and cloned a soybean AAP gene renamed GmAAP6-like. Growth and uptake studies using treatments with single toxic amino acid analogs or single amino acids as a sole nitrogen source indicated that GmAAP6-like is involved in the selective transport of neutral and alkaline amino acids but is not sensitive to high concentrations of acidic amino acids. Overexpression of GmAAP6-like resulted in enhanced resistance to the toxic Glu analog, MSX, by significantly inducing jasmonic acid biosynthesis and signal transduction. We further evaluated the contribution of GmAAP6-like overexpression to seed quality and yield, and the tolerance of transgenic Arabidopsis seedlings to nitrogen deficiency. This study revealed the gene function of GmAAP6-like, improving the understanding of the functions and mechanisms of AAP family genes in soybeans.