Enhanced Disease Resistance Mechanism of the CmoAP2/ERF Transcription Factor in Pumpkin through Genetic Mutations

The squash species Cucurbita moschata has been historically utilized by both animals and humans as a food source. It is an annual dicotyledonous vegetable known for its health benefits, including reducing the risk of various diseases, such as cancer, high blood pressure, diabetes, intestinal disorders, and atherosclerosis, in humans. However, the cultivation of this valuable crop is often challenged by diseases such as powdery mildew (PM), caused by the fungus Podosphaera xanthii. PM not only reduces yield but also impacts photosynthesis rates. A newly identified gene called CmoCh3G009850, which encodes the transcription factor known as AP2-like ethylene-responsive factor (CmoAP2/ERF), has been marked for resistance against PM. A shift in the state from susceptible to resistant can be induced by nonsynonymous SNP mutations at five locations of the CmoCh3G009850 gene. The dynamical studies of the wild-type (WT) and mutated-type AP2/ERF proteins' interactions with DNA were explored by docking and molecular dynamics simulation studies. These five mutations T105A, S302R, H321R, H335D, and V402A are incorporated in the AP2/ERF transcription factor that makes a stable and compact complex with DNA rather than the WT protein. Overall, the identification and characterization of the CmoAP2/ERF gene and its variants represent a significant advancement for the breeding and cultivation of C. moschata varieties resistant against powdery mildew. This study not only enhances our understanding of plant-pathogen interactions but also provides a potential avenue for developing more resilient squash varieties through genetic improvement.