Related Experiment Video
Updated: Jun 5, 2026
06:52
Characterizing Herbivore Resistance Mechanisms: Spittlebugs on Brachiaria spp. as an Example
Published on: June 19, 2011
Do grasses fight back? The case for antiherbivore defences
1Dept of Biology, York University, 4700 Keele Street, North York, Ontario, Canada M31 I P3.
Trends in Ecology & Evolution
|January 18, 2011
Summary
Grass-grazer interactions are often viewed as mutualistic, but intense grazing likely selected for grass antiherbivore defenses. Plants with higher silica and secondary compounds deter herbivores more effectively, challenging mutualism theories.
Area of Science:
- Plant-herbivore interactions
- Plant defense mechanisms
- Ecology
Background:
- Grass-grazer interactions have historically been debated as mutualistic.
- Intense grazing pressure may drive the evolution of plant antiherbivore strategies.
- Plant defenses are crucial in shaping herbivore behavior and plant community dynamics.
Purpose of the Study:
- To explore the role of antiherbivore defenses in grasses under grazing pressure.
- To evaluate the effectiveness of physical and chemical defenses in deterring herbivores.
- To re-examine the traditional view of grass-grazer interactions.
Main Methods:
- Review of existing evidence on grass defenses.
- Analysis of the impact of silica and secondary compounds on herbivores.
- Comparison of herbivore deterrence levels in plants with varying defense strategies.
Main Results:
- Grasses possess diverse antiherbivore defenses, including silica and secondary compounds.
- Silica acts as a physical deterrent to herbivores.
- Secondary compounds negatively impact both invertebrate and vertebrate herbivores.
- Higher levels of plant defenses correlate with increased herbivore deterrence.
Conclusions:
- Grass-grazer interactions are more likely shaped by plant defenses than mutualism.
- Antiherbivore defenses are key adaptations for grasses facing herbivory.
- Evidence supports the efficacy of plant chemical and physical defenses in deterring herbivores.
Related Concept Videos
02:26Defenses Against Pathogens and Herbivores
Plants present a rich source of nutrients for many organisms, making it a target for herbivores and infectious agents. Plants, though lacking a proper immune system, have developed an array of constitutive and inducible defenses to fend off these attacks.
02:22Introduction to Plant Diversity
From Water to Land
01:56Plant Hormones
Plant hormones—or phytohormones—are chemical molecules that modulate one or more physiological processes of a plant. In animals, hormones are often produced in specific glands and circulated via the circulatory system. However, plants lack hormone-producing glands.
02:39Predator-Prey Interactions
Predators consume prey for energy. Predators that acquire prey and prey that avoid predation both increase their chances of survival and reproduction (i.e., fitness). Routine predator-prey interactions elicit mutual adaptations that improve predator offenses, such as claws, teeth, and speed, as well as prey defenses, including crypsis, aposematism, and mimicry. Thus, predator-prey interactions resemble an evolutionary arms race.Although predation is commonly associated with carnivory, for...
01:57Adaptations that Reduce Water Loss
Though evaporation from plant leaves drives transpiration, it also results in loss of water. Because water is critical for photosynthetic reactions and other cellular processes, evolutionary pressures on plants in different environments have driven the acquisition of adaptations that reduce water loss.
02:40Epiphytes, Parasites, and Carnivores
Plants often form mutualistic relationships with soil-dwelling fungi or bacteria to enhance their roots’ nutrient uptake ability. Root-colonizing fungi (e.g., mycorrhizae) increase a plant’s root surface area, which promotes nutrient absorption. While root-colonizing, nitrogen-fixing bacteria (e.g., rhizobia) convert atmospheric nitrogen (N2) into ammonia (NH3), making nitrogen available to plants for various biological functions. For example, nitrogen is essential for the biosynthesis of the...