Symbiont

Definition

A symbiont is an organism that lives in close association with another organism, often to the mutual benefit of both. In plant nutrition, symbionts can help plants acquire nutrients from the soil more efficiently.

5 Must Know Facts For Your Next Test

1. Symbionts such as mycorrhizal fungi enhance a plant's ability to absorb water and nutrients like phosphorus.
2. Rhizobia bacteria are symbionts that form nitrogen-fixing nodules on legume roots, converting atmospheric nitrogen into a form usable by plants.
3. Symbiotic relationships can increase a plant's resistance to pathogens and environmental stressors.
4. Plants often provide carbohydrates produced through photosynthesis to their symbionts as an energy source.
5. Ectomycorrhizae and endomycorrhizae are two types of mycorrhizal associations based on whether the fungal hyphae penetrate plant root cells.

Review Questions

Related terms

Mycorrhizae: Symbiotic associations between fungi and plant roots that enhance nutrient absorption.

Rhizobia:

Nitrogen-fixing bacteria that form nodules on the roots of legumes.

Endophytes: Microorganisms, often fungi or bacteria, that live inside plant tissues without causing harm.