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The Surprising Role of Mycorrhizal Fungi in Plant Growth

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Do you always have trouble when it comes to getting good yields with your vegetables or flowers? A damaged or underdeveloped root system might be the cause because you have never maximized the use or even investigated how mycorrhizal (plural mycorrhizae) fungi can benefit your plants.

If you have ever decorated a Christmas tree, enjoyed the shade of an oak, or eaten a chanterelle or a blueberry, then you have benefited from mycorrhizal fungi – it makes the survival of most plants possible.

How do Mycorrhizal Fungi Help Plants? Mycorrhizal Fungi help plants as they work synergistically with the plant to provide additional water and nutrients that the plant’s root system would not be able to reach alone. The fungi attach themselves to the root system and help to increase the mass of the plant’s root system. In turn, the plants provide carbohydrates that the fungi need to survive.

What are mycorrhizal Fungi?

Have you ever had to work in a garden or grow a single plant? If so, you know it requires hard work – you must carefully cultivate the growth of your plants by keeping every weed at bay and offering the plants enough essential requirements, including water and sunshine.

And in the end, your efforts and hard work are rewarded with plenty of healthy nutrients in the form of fresh, delicious vegetables or a backyard of beautiful flowers.

Are you aware that many plants have their gardens too? Unlike our natural gardens, the plants’ gardens are underground; usually, you can not see them for a short period each year. These “plant gardens” are called mycorrhizae – they live in symbiotic relationships with the plants.

Mycorrhizae are fungi that exist as tiny, microscopic threads referred to as hyphae. They are interconnected into a net-like web (mycelium) that measures thousands of miles, packaged into a tiny area around a plant’s root system. Mycorrhizae can also be described as the symbiotic relationship between a fungus and the root of a plant.

This association is referred to as symbiotic because the relationship benefits both organisms. The macrosymbiont (the plant) accesses increased soil exploration (rhizosphere) with the intricate hyphae net that raises water and nutrient uptake from soil interphase. While the microsymbiont (the fungus) uses carbon offered by the plant for its physiological purposes, growth, and development.

How do the microbes and nutrients get into a plant?

This is a microscopic view of the roots. Most folks think the roots are pieces of plants underneath that soak up water. The root system acts as an anchoring device – roots hold plants in the ground. Whether it’s a tree or a turf, roots are the anchor.

The root hair – something we can’t see with the naked eye – if these hairs get damaged and/or the soil surrounding them is full of salts such that the nutrients and microbes load can’t enter into these root hairs, the soil becomes useless to both you and your plants.

So once mycorrhizae fungi get into root hairs, they expand and grow as they feed on roots. They establish a symbiotic relationship. As long as you feed your soil with the right nutrients, these fungi stay alive longer than you could imagine!

Relationship between mycorrhizal fungi and a plant

Most importantly, consider using these inoculants in the next growing cycle if you want to determine how mycorrhizal fungi can significantly benefit your plants. Ideally, various factors influence both plant nutrition and yield.

Apart from plant genotype, water availability, and uptake, environmental factors like the availability of nutrients in the growing media and the ability of a certain plant to properly use what is available in the soil, all play an important role in plant growth.

Plants form a mutually beneficial association with arbuscular mycorrhizae to enhance these processes. These soil fungi play an integral role in plant nutrition by enhancing water and nutrient uptake from the soil and can form a mutualistic symbiotic relationship with many plant species (more than 85%), inclusive of all major agricultural as well as horticultural crops.

The fossil evidence proposes that this symbiotic association dated back to more than 400 millennials and played an important role in enhancing plant mitigation from seas onto dry land and also using terrestrial habitats. Without arbuscular mycorrhizal fungi, crop plants would probably not exist, nor would there be life on land, as everybody knows.

This association is initiated after mycelia are manufactured through a spore and stretch to connect with plant roots. Mycelia penetrates the cell membrane, stretching into the root cortex, bridging a gap between the soil biome and the root.

These fungi establish arbuscules (specialized structures that act as nutrient exchange sites within the cell) and vesicles (as storage sites). In this symbiosis, the plant is offered better access and uptake of water and nutrients from the soil. Mycorrhizal fungi help with these processes in favor of photosynthetic carbon from plants.

How do mycorrhizal fungi help plants?

The beneficial growth and development responses to mycorrhizal fungi are best attributed to the following mechanisms:

  • Increased soil’s physical exploration
  • Increased availability of nutrients within growing media
  • Increased uptake of nutrients
  • Access to storage sites of all absorbed minerals
  • Decreased salts and toxic minerals uptake

Increased soil’s physical exploration

The increased absorption of different mineral nutrients, including phosphorus, by most mycorrhizal plants has raised the surface area for plants’ nutrient absorption. The root system of the plant act as the main absorbing organ of both water and mineral nutrients.

Inside the soil, the roots of plants are limited to a small surface area for nutrient absorption. At the same time, hyphae (of arbuscular mycorrhizal fungi) develop beyond the depletion area where plant roots have already absorbed all the available nutrients and water.

The absorptive surface area of roots can go up to 50 times in every mycorrhizal plant (with fungal hyphae reaching beyond the root section by 4 to more than 20 cm) when compared to non-mycorrhizal plants.

Increased availability of nutrients within growing media

Several researchers claim that mycorrhizal fungi can solubilize otherwise insoluble nutrients. The activity of the mycorrhizal phosphatase enzyme converts all phosphate into soluble forms and allows mycorrhizal plants to absorb more phosphorus than non-mycorrhizal ones.

Studies demonstrate that the extraradical hyphae (of Glomus intraradices) could hydrolyze exogenously produced organic phosphorus and transport significant amounts of phosphorus to plant roots.

Various mycorrhizal plants like wheat, marigold, corn, and onion can raise the activity of phosphatase in roots and so organic phosphorus hydrolysis. Molecular changes brought about by mycorrhizal fungi in plant roots raise the ability of plants to convert insoluble organic phosphorus into bioavailable phosphorus forms.

These fungi also play an integral part in the uptake and conversion of nitrogen into bioavailable forms. Mycorrhizal increases decomposition and subsequent inorganic nitrogen capture from complex material like plant litter. The fungi can facilitate organic residue degradation and uptake of nitrogen by the host plant.

Increased uptake of nutrients

The rate of nutrient uptake facilitated by mycorrhizal fungi is generally faster than non-mycorrhizal roots. This fungus possesses a high affinity for mineral ions and a lower threshold concentration to absorb than what plant roots do.

The finest mycorrhizal hyphae in the soil typically have a diameter of about two μm compared to fine-root diameters of 100-500 μm and root-hair diameters of 10 to 20 μm. Therefore, it’s evident that hyphae are about ten times more efficient than root hairs and 100 times more than fine roots.

Access to storage sites of all absorbed minerals

As explained earlier, arbuscular mycorrhizal fungi form specialized structures (vesicles) that serve as storage sites inside a plant’s roots and store absorbed lipids and minerals. These absorbed nutrients act as reserves, becoming easily accessible by host plants when there is a limited supply.

Decreased salts and toxic minerals uptake

Mycorrhizae have been demonstrated to protect plants from not only saline conditions but also the uptake of heavy metals, assisting the plant to prevent nutrient lockout situations. These fungi can mitigate salts’ uptake, thus balancing the uptake of toxic ions like Na+ and Cl- hence permitting plants to uptake other useful ions like K+, Mn2+, and Ca2+.

Also, plants colonized by mycorrhizal fungi have been claimed to possess a buffer between heavy metals and plants, avoiding the uptake of other elements such as zinc, copper, aluminum, and arsenic. This may be why Studies have been inconclusive when growing potatoes in tires. Check out that blog here.

Heavy metal accumulation in plants can result in various symptoms like suppressed growth and development, chlorosis, root browning and, in extreme cases, the death of plants. This resistance of heavy metals has been found to manifest through the sequestration of these metals in most fungal tissues as well as by improved nutrition of phosphorus in plants.


Mycorrhizal fungi use, especially in greenhouses production, is a no-brainer. Through plant-root connection and hyphal mass, these fungi assist in raising the absorption of water, raising the uptake of nutrients, increasing the availability of nutrients that aren’t available to the roots of plants, and protection from harmful minerals or excess salts.

Moreover, these fungi can extend farther into the soil than plant roots because they possess various mechanisms to ensure your plants get the desired TLC. Without a doubt, this is a truly beneficial association for plants and also container growers.

Consider applying these inoculants during your next growing cycle to determine how mycorrhizae can benefit your plant. Or, at the minimum, run a comparison trial to see how you can lower the inputs and increase plant performance by maximizing mycorrhizae usage. Sooner or later, you will notice the power of these fungi when it comes to rooting!

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And remember, folks, You Reap What You Sow!