1. Changes in cuticle composition: The cuticle is a waxy layer that covers the surface of plants and helps to protect them from pathogens. As fruit ripens, the cuticle becomes thinner and more permeable, allowing pathogens to more easily penetrate the fruit.
2. Increased sugar content: Ripe fruit has a higher sugar content than unripe fruit. This increase in sugar provides a more favorable environment for the growth of necrotrophic pathogens, which are able to use sugars as a source of energy.
3. Reduced acidity: Ripe fruit is less acidic than unripe fruit. This reduction in acidity makes it easier for necrotrophic pathogens to survive and grow within the fruit.
4. Increased ethylene production: Ethylene is a plant hormone that is involved in the ripening process. Increased ethylene production during ripening leads to the breakdown of cell walls and other structural components of the fruit, making it more susceptible to infection by necrotrophic pathogens.
5. Altered gene expression: The ripening process is accompanied by changes in gene expression in the fruit. These changes can affect the production of defense-related proteins and other compounds that help to protect the fruit from pathogens.
Taken together, these factors contribute to the increased susceptibility of ripe fruit to necrotrophic pathogens. By understanding these factors, it is possible to develop strategies to reduce the risk of infection and spoilage of ripe fruit.
