SlABCG9 Functioning as a Jasmonic Acid Transporter Influences Tomato Resistance to .

Jasmonic acid (JA) is crucial for plant stress responses, which rely on intercellular jasmonate transport. However, JA transporters have not been fully identified, especially in tomato ( L.). This study reveals that plasma-membrane-localized protein SlABCG9 in tomato regulates fruit resistance to . Transcriptomic analysis indicated that the expression was significantly upregulated after infection. Assays using oocytes, yeast cell sensitivity, and JA-inhibited primary root growth confirmed that SlABCG9 functions as a JA influx transporter. The knockout mutant lines of showed decreased JA contents, suppressed defense gene 's expression, reduced antioxidant enzyme activity, and severe disease symptoms compared to wild-type controls. Our findings provide new knowledge for understanding how the JA transporter and signaling pathway are involved in the biotic stress responses and improve the resistant ability against pathogen infections.