Life › Seas, forests & the move to land › Plants colonize land
Plant–fungus partnerships (mycorrhizae)
from early land plants; proven by 407 million years ago· Evolutionary innovation· Plants & fungi
Strong evidenceGood evidence; dates or details still being refined.
Partnerships in which fungi supply plants with water and minerals in exchange for sugars, probably dating back to the first land plants.
See it on the Life map →What happened
Early land plants lacked roots. Fungal threads living in and around them reached into rock and grit, delivering phosphorus, nitrogen and water; the plant paid in sugars and fats made by photosynthesis. Fossil fungal spores about 460 million years old come from Wisconsin, and 407-million-year-old plants in Scotland's Rhynie chert show branched fungal structures (arbuscules) inside their cells. Today roughly 80% of land plant species still have fungal partners.
Why it matters
The partnership probably helped make the move onto land possible, and it still underpins forests, crops and the carbon stored in soils.
Think of it like
Like a supply contract: the fungus delivers raw materials from the site; the plant pays in sugar.
The evidence (fossils, genes, rocks)
Rhynie chert fossils with fungi inside plant cells (described 1994), Ordovician fungal spores, and shared 'symbiosis genes' across living land plants and their algal relatives.
Still debated
Whether fungi were essential for the very first step onto land or joined slightly later, and which fungal groups were the earliest partners.
Connections (2)
▸Plants colonize land relied on Plant–fungus partnerships (mycorrhizae)Strong evidence
The connection
The first land plants had no roots. Fungal partners threaded through bare grit, extracting phosphorus and water and passing them to the plants in exchange for sugars. Many scientists think this partnership is what made life on rocky, soil-less ground possible for early plants.
When and how
From the earliest land plants, perhaps 470 million years ago or before; seen clearly in Scotland's Rhynie chert, about 407 million years ago.
How sure are we?
Fungi inside cells of Rhynie plants, fossil fungal spores about 460 million years old, and symbiosis genes shared by liverworts and other land plants.
Debates and open questions
Whether fungi were needed for the first step onto land or joined soon after, and which fungal groups were involved first.
▸Fungi formed Plant–fungus partnerships (mycorrhizae)Strong evidence
The connection
Fungi feed by absorbing nutrients through networks of fine threads (hyphae). Some fungi came to live in and around plants, trading minerals and water pulled from the ground for the plant's sugars. These partnerships were formed by early fungal groups related to today's Glomeromycota and Mucoromycotina.
When and how
From early land plants, perhaps 470 million years ago; preserved in Scotland's Rhynie chert, about 407 million years ago.
How sure are we?
Fossil fungi inside Rhynie plant cells resemble living mycorrhizal fungi, and DNA family trees date these fungal groups to before or alongside land plants.
Debates and open questions
Fungi may be a billion years old, based on debated fossils; when they first met plants, and which group partnered first, is unresolved.