Induced Resistance

Definition

Induced resistance is a plant's ability to enhance its defenses against pests and diseases in response to specific stimuli, such as herbivore attacks or pathogen infections. This adaptive response allows plants to activate their innate defense mechanisms, leading to increased resilience against future threats. Understanding how induced resistance works is crucial for developing natural pest resistance strategies that minimize the need for chemical pesticides.

5 Must Know Facts For Your Next Test

1. Induced resistance can be triggered by various factors including herbivore feeding, pathogen presence, or even mechanical damage to the plant.
2. This resistance often involves the production of secondary metabolites, like phytoalexins and pathogenesis-related proteins, which directly deter pests or inhibit pathogen growth.
3. Induced resistance is usually more effective than constitutive defenses, which are always present but may use more resources for the plant.
4. The phenomenon of induced resistance can also result in trade-offs; while it enhances defense, it may temporarily affect plant growth and reproduction.
5. Practices such as crop rotation and intercropping can help stimulate induced resistance in plants by promoting diversity and disrupting pest cycles.

Review Questions

• How does induced resistance differ from constitutive plant defenses?
  • Induced resistance is a dynamic response that plants activate in reaction to specific stimuli like pest attacks, while constitutive defenses are always present in the plant regardless of external threats. This means that induced resistance can be more resource-efficient since it only occurs when needed, allowing the plant to allocate energy towards growth and reproduction when threats are low. In contrast, constitutive defenses often require constant energy investment and may not be as flexible in adapting to changing environmental conditions.
• Discuss the role of phytohormones in the process of induced resistance and how they contribute to a plant's defense mechanisms.
  • Phytohormones are essential players in induced resistance as they mediate the signaling pathways that trigger defense responses. For instance, jasmonic acid is involved in activating defenses against herbivores, while salicylic acid primarily regulates responses to pathogens. By coordinating these hormonal signals, plants can effectively ramp up their defensive strategies, ensuring that they respond appropriately depending on the type of threat they face. This hormonal interplay not only enhances the plant's immediate defense but also helps establish long-term immunity through systemic acquired resistance.
• Evaluate the implications of utilizing induced resistance strategies in sustainable agriculture practices.
  • Utilizing induced resistance strategies in sustainable agriculture has significant implications for pest management and environmental health. By promoting plants' natural defense mechanisms, farmers can reduce reliance on chemical pesticides, thus minimizing potential negative impacts on non-target species and ecosystems. Additionally, practices that stimulate induced resistance can lead to healthier crops with improved resilience against pests and diseases, ultimately contributing to higher yields. However, it is essential to balance these strategies with the understanding of ecological interactions and the potential trade-offs involved to ensure long-term sustainability in agricultural systems.

Related terms

Systemic Acquired Resistance: A plant-wide immune response that occurs after an initial localized attack, providing long-lasting protection against a wide range of pathogens.

Phytohormones: Natural plant hormones that play a key role in regulating growth, development, and responses to environmental stressors, including pest attacks.

Biological Control: The use of living organisms, such as predators or parasites, to control pest populations in an ecosystem, promoting a natural balance.