Disease resistance refers to the ability of a plant to prevent, limit, or overcome infection by a pathogen such as a virus, bacteria, or fungus. This trait allows plants to withstand diseases that would otherwise negatively impact growth and crop yield.
There are two main types of disease resistance in plants:
- Passive resistance involves physical or structural barriers that prevent infection in the first place. Examples include waxy skin layers, hairs, bark, and specialized cell walls. These barriers physically block pathogens from entering and infecting the plant.
- Active resistance involves the plant recognizing specific proteins produced by certain pathogens and triggering defense responses such as:
- Hypersensitive response (HR) - the plant cells surrounding an infection intentionally die to prevent further spread of the pathogen.
- Systemic acquired resistance (SAR) - defense proteins are produced that signal a systemic response throughout the entire plant.
- Induced systemic resistance (ISR) - beneficial soil microbes trigger the plant's immune system.
Plants can have
genetic resistance to specific pathogen strains coded in their DNA. Alternatively, resistance can be acquired throughout a plant's life via prior exposure.
There are significant
benefits of disease resistance in crops:
- Increased yield and quality
- Reduced need for pesticides
- Lower environmental impact
- More sustainable and cost-effective production
Breeding for genetic disease resistance is crucial for
food security. As the global population grows, so too must the resilience and dependability of our crops in the face of evolving pathogen and climate threats. The durability and stability of disease resistance over long periods of time makes it a top priority for plant breeders seeking to feed future generations.