Crown rot, caused by Colletotrichum siamense, is a devastating hemibiotrophic fungal disease that poses a significant threat to the strawberry industry. Salicylic acid (SA) is known to play a critical role in plant defense responses to biotic stress. However, its contribution to mitigating strawberry crown rot remains unclear due to the microbial isolate-specific sensitivity and cultivar/tissue-specific responses in strawberries. In this study, we aimed to investigate how exogenous supply of SA influenced crown rot in strawberry. Exogenous SA application significantly reduced C. siamense infection in strawberry crowns, evidenced by the lesion size and pathological analysis. Transcriptomic data showed that for each sample of SA pretreatment and mock, owing to nearly 50 million reads, the ratio of Q20 ranged from 98% to 99%, and 91.63%-94.29% of the reads mapped to the reference genome. The SA pretreatment up-regulated genes encoding MLO-like protein 2, receptor-like kinase, peroxidase, and caffeic acid 3-O-methyltransferase involved in lignin biosynthesis. The SA pretreatment also down-regulated chalcone isomerase, naringenin 3-dioxygenase, bifunctional dihydroflavonol 4-reductase, anthocyanidin synthase, and anthocyanidin reductase expressions involved in flavonoid biosynthesis during C. siamense infection. Consistent with gene expression changes, the SA pretreatment remarkably enhanced peroxidase activity and lignin content and decreased flavonoid content and chalcone isomerase activity after C. siamense inoculation. The results suggest that exogenous SA enhanced strawberry resistance to crown rot caused by C. siamense by up-regulating defense-related genes and lignin biosynthesis.
Article Type:
Original Research |
Subject:
Pomology Received: 2024/07/18 | Accepted: 2024/01/1