Disease resistance refers to the ability of a plant to prevent, restrict, or reduce the effects of a pathogen or disease. It involves complex biochemical and cellular mechanisms that enable plants to recognize disease-causing organisms and mount an effective defense response.
There are two main types of disease resistance in plants:
- Passive resistance involves physical or structural barriers that prevent pathogens from successfully infecting the plant. Examples include the waxy cuticle on leaves, cell walls that block pathogen entry, or bark that protects stems and roots. These pre-existing barriers are always active.
- Active resistance involves molecular defenses that are activated after the plant detects a pathogen. This can include:
- Hypersensitive response - programmed cell death at infection sites, stopping the pathogen from spreading further
- Antimicrobial compounds - chemicals produced to kill or deactivate pathogens
- Production of pathogenesis-related (PR) proteins with antimicrobial activities
Active resistance is more specific than passive and triggered by "detection" of a particular pathogen. Plants have surveillance systems to recognize disease-causing microbes by their elicitors or secretions. This initiates signal transduction pathways that lead to defense gene activation.
Some key points about plant disease resistance:
- Resistance can be complete (the plant shows no symptoms or damage from the disease) or partial (the plant shows reduced symptoms and less damage with the disease).
- Resistance can be race-specific (effective against certain races or strains of a pathogen species) or broad-spectrum (effective against multiple strains or pathogen species).
- Resistant varieties are bred by plant breeders to incorporate genetic resistance traits from wild plant relatives through crosses. These traits enable crops to withstand major diseases without significant yield losses.
I hope this provides an informative overview explaining what disease resistance encompasses in plants. Visit Harmony MD for more information.