BioProject

Background: Sclerotinia sclerotiorum is one of the most severe fungus diseases in many important crops including sunflower (Helianthus annuus) worldwide. More...

Background: Sclerotinia sclerotiorum is one of the most severe fungus diseases in many important crops including sunflower (Helianthus annuus) worldwide. Breeding the resistant varieties are the best strategy to control S. sclerotiorum, however, the molecular regulatory mechanisms of sunflower in response to S. sclerotiorum remain poorly understood. Methods: We performed a leaf transcriptomic analysis to understand the differential defense response to S. sclerotiorum in a disease resistant (DR) genotype and a disease susceptible (DS) genotype of sunflower 24 h post-inoculation. Results: A total of 7439 and 10151 differentially expressed genes (DEGs) were identified in DR and DS genotypes, respectively suggesting that the former is less affected by S. sclerotiorum infection. Pathway analysis revealed that response to S. sclerotiorum was mostly enriched in the DEGs that are involved in the cell wall, redox homeostasis, immune response, protein kinase activity, hormone, transcription factor activities as well as secondary metabolism. The magnitude of expression changes in a set of genes encoding expansins, pectate lyase activities, antioxidant activity and ethylene following S. sclerotiorum infection likely contributed to the different resistance levels of these two genotypes. One gene encoding effector receptor NLR revealing significant opposite expression pattern between DR and DS genotypes along with three hub-genes CDPK9, MAPK5, CML23 by protein-protein interaction (PPI) network analysis were considered as the most possible candidate genes. Conclusion: Our results provide in-depth insights into the molecular mechanisms associated with sunflower defense responses against S. sclerotiorum that will be of great utility in Sclerotinia-resistance breeding. Overall design: We performed a leaf transcriptomic analysis to understand the differential defense response to S. sclerotiorum in a disease resistant (DR) genotype and a disease susceptible (DS) genotype of sunflower 24 h post-inoculation. Less...