Role of oligandrin in enhancing post-harvest disease resistance in cherry tomato through salicylic acid and jasmonic acid signaling pathways

Salicylic acid (SA) and jasmonic acid (JA) pathways are crucial components of plant defense mechanisms; however, their roles in post-harvest preservation remain inadequately explored. Cherry tomatoes are highly susceptible to fungal pathogens, such as <i>Alternaria nees</i>, after harvest, leading to significant post-harvest losses. This study investigates the effects of oligandrin, an elicitin protein derived from <i>Pythium oligandrum</i>, on enhancing the resistance of harvested cherry tomatoes to <i>A. nees</i>. Oligandrin treatment significantly reduced disease symptoms, including black spots and decay, during storage without affecting <i>A. nees</i> spore germination. Treated samples exhibited enhanced activities of defense-related enzymes, including polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia-lyase (PAL), and catalase (CAT), compared to controls. Key SA-responsive genes, such as <i>NPR1</i> (Non-expressor of Pathogenesis-Related Genes 1), <i>TGA2</i> (TGACG-Binding Factor 2), <i>WRKY70</i>, and <i>PR1</i> (Pathogenesis-Related Protein 1), were upregulated within 48 h, indicating activation of the SA signaling pathway. Additionally, <i>JAZ1</i> (Jasmonate ZIM-Domain 1), a negative regulator of JA signaling, was elevated at both 24 and 48 h, while <i>MYC2</i> (Myelocytomatosis 2), a transcription factor involved in the JA pathway, showed significant upregulation, suggesting activation of the JA signaling pathway. These findings demonstrate that oligandrin enhances post-harvest fungal disease resistance by modulating both SA and JA pathways and sustaining elevated defense enzyme activity, offering a promising strategy for improving post-harvest preservation and quality maintenance of cherry tomatoes.IMPORTANCEThis study provides compelling evidence that oligandrin activates both salicylic acid and jasmonic acid signaling pathways in cherry tomatoes, enhancing resistance to <i>A. nees</i>. This dual activation not only deepens our understanding of oligandrin's mechanisms but also underscores the potential of oligandrin and its producer <i>P. oligandrum</i> as a biocontrol agent for post-harvest preservation. By modulating plant immunity and promoting defense enzyme activity, oligandrin strengthens resistance to fungal diseases, offering a promising strategy for maintaining the quality and extending the shelf life of berry-like crops. Given the successful use of <i>P. oligandrum</i> as a biopesticide in Europe and North America, oligandrin and its producer <i>P. oligandrum</i> present an environmentally friendly alternative to chemical pesticides for post-harvest disease management. This research lays the groundwork for further studies aimed at optimizing the application of <i>P. oligandrum</i> in real-world agricultural settings, establishing it as a reliable, sustainable tool for both agricultural and post-harvest management practices. These findings contribute to advancing biocontrol strategies for safer, more sustainable food production systems.