Mycorrhiza
மைக்கோரைசா
Do not mistake Mycorrhiza for a simple parasite. It is a sophisticated evolutionary trade-off between fungi and plant roots. If you confuse this with Lichen, you lose marks on basic symbiotic classification.
The idea
Mycorrhiza is a symbiotic association between fungi and the roots of higher plants. The fungal genus Glomus is the primary example cited in NCERT. The fungus absorbs phosphorus from the soil and transfers it to the plant. Additionally, it confers resistance to root-borne pathogens and increases tolerance to salinity and drought.
Why it matters
It exists as a mutualistic relationship where the fungus gains carbohydrates from the plant, and the plant gains enhanced nutrient uptake and stress tolerance.
NEET lens
NEET focuses on the specific role of Glomus in phosphorus absorption. Expect questions matching the fungus to its function or the type of association. Do not confuse the 'phosphorus' benefit with 'nitrogen fixation' performed by Rhizobium. Memorize the genus name Glomus; it is a high-yield keyword.
Clinical significance
In an ecosystem, the failure of Mycorrhizal networks leads to nutrient deficiency and stunted plant growth, disrupting the primary productivity of the food chain. While not a human disease, its absence mirrors the impact of gut microbiome depletion in humans, where nutrient absorption efficiency collapses.
Introduction
Mycorrhiza is a symbiotic association between fungi and the roots of higher plants. Many members of the genus Glomus form mycorrhiza.
Core concept
Benefits (NCERT): the fungal symbiont absorbs phosphorus from the soil and passes it to the plant. Plants with such associations also show resistance to root-borne pathogens, tolerance to salinity and drought, and an overall increase in plant growth and development. Mycorrhizae are therefore used as biofertilisers. Pinus seeds cannot germinate and establish without fungal association because the mycorrhizal fungi help the seedling absorb water and minerals (especially phosphorus). Mycorrhiza is an example of mutualism.
Go deeper
Mycorrhizal hyphae greatly extend the absorbing surface of roots — they reach far into the soil where root hairs cannot go.
From Class 10
Some fungi live together with plant roots and help the plant absorb nutrients; the plant gives the fungus food in return.