Symbiosome membrane-localized cationic amino acid transporters support symbiotic nitrogen fixation in Medicago truncatula.

ABSTRACT: Legumes engage in nitrogen-fixing symbiosis with rhizobia, in which host legumes supply dicarboxylates as a carbon source to rhizobia, while rhizobia reciprocate by providing ammonium to the host plants. Beyond this classical model, accumulating evidence suggests that amino acid exchange is also essential for legume-rhizobium symbiosis. However, it remains unclear whether amino acid transporters are present on the symbiosome membrane (SM) to mediate amino acid exchange during symbiotic nitrogen fixation (SNF). In this study, we identified three amino acid transporters in Medicago truncatula-MtCAT1a, MtCAT1b, and MtCAT1c-which belong to a clade of the plant Cationic Amino acid Transporter (CAT) family known to transport a wide range of amino acids. Notably, MtCAT1b and MtCAT1c are predomina

SUBMITTER: Wu J 

PROVIDER: S-EPMC12903387 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature