Impacts of ectomycorrhizal fungi on plants(:Muhammad Hanif Kalyar)

Assignment Topic:

Impacts of ectomycorrhizal fungi on plants

Submitted to; Dr.Muhammad iqbal Husain 

(Associate professor GCUF Faisalabad)

Submitted by;

Muhammad Hanif Kalyar

Introduction;

•  Mycorrhizae .it is mutualistic relationship between fungal component and vascular plant roots in which both partner are benefited and neither is harmed

•  The symbiotic association between plant and fungi (mycorrhizal association) is a tremendous phenomenon observed in nature.

• The mycorrhizal association is one among nature’s boons for sustainable agriculture. In today’s changing environment, indiscriminate use of pesticides and chemicals pose an excellent threat to the existence of mycorrhizal species. There is a requirement to spread awareness so as to save lots of mycorrhizal fungi from extinction.

•  this term mycorrhiza is derived from two Greek words  i.e myco mean ,fungus, and rhiza mean ,roots,,.

•  In nature, quite eighty percent of angiosperms, and most gymnosperms are known to possess mycorrhizal associations.

•  Mycorrhizae  produced hollow tubular thread like structure  called hyphae and its group is called mycelium.it ranges in  size  2–10 μm in diameter that increases the absorption area of the plants, that grow out into the soil from the mycorrhizal root. These external hyphae ramify the soil and, by virtue of their small diameter, the hyphae penetrate soil microsites which are inaccessible to plant roots to ext

• ending the quantity of soil accessible to plants.

Types of mycorrhiza:

Seven major types of mycorrhiza are now recognized:

• Ectomycorrhizae (EM)

•  Endomycorrhizae / Arbuscular (AM)

•  Ectendomycorrhizae

•  Monotropoid mycorrhizae,

•  Arbutoid mycorrhizae,

•  Orchid mycorrhizae,

• Ericoid mycorrhizae,

these above types are different from each other on the basis of their structure ,functions that produce on the basis of evolution in their genetics.
These mycorrhizal associations occurred in all early-diverging lineages of land plants, such as liverworts and hornworts.

It evolved ~ 300–400 million years before the appearance of root nodule symbioses with N2-fixing bacteria.

There are mainly two types of mycorrhizal endomycorrhizae or arbuscular-mycorrhizae (AM), eg., Endogone, Rhizophagus, etc. and ectomycorrhizae (EM), eg., Laccaria bicolor, Amanita mascaria.

Endomycorrhizae (arbuscular mycorrhizae) are found within the root zones for many vascular plants.
Ectomycorrhizae:

•  Ectomycorrhizae is one among the three main sorts of mychorrizal fungi.

•  Ectomycorrhizae makes association in between the intercellular spaces of root cells like in oats,firs etc

•  Ectomycorrhizal (EMF) associations are mutualistic associations between higher fungi and certain groups of Gymnosperms and Angiosperms. The majority of fungi that form EMF associations are Basidiomycetes and Ascomycetes, plus a few Zygomycetes .

•  They associate primarily with woody perennial plants in the Salicaceae, Betulaceae, Fagaceae, Pinaceae, Myrtaceae and other

• Difference between ecto and endomycorrhizae:

•  Ectomycorrhizae is said to, but to to not be confused with Endomycorrhizae, which may be a relationship where the fungi actually penetrates the roots. Ectomycorrhizae don't penetrate root cells; they simply colonize round the root zone of the plant..

•  Ectomycorrhizal fungi are a distinct group of mutalistic fungi that are characterized by a hyphal sheath that envelops the root, a Hartig net, fungal hyphae which penetrate between the root epidermal and cortex cell.

Impacts of EMF on Plants

•  Ectomycorrhizal fungi are relatively selective of host plants and, as a result, any benefits to a plant are ultimately determined by the ability of the fungal species to form mycorrhizae with the potential host plant. ( host specific)

•  Since ectomycorrhizal fungi depend on their host plants, it is feasible that sites devoid of vegetation for some time also lack native fungi, hyphae, and possibly spores.

•  Ectomycorrhizal fungi can colonize a much greater volume of soil than roots alone and increase the absorptive surface of plant roots

•  Ectomycorrhizal fungi in the mobilization and transport of various nutrients to the host plant.

•  Heavy metal contamination of the soil resource further reduces the availability of plant essential nutrients increasing the importance of ectomycorrhizal fungi in plant survival.

•  Ectomycorrhizal fungi alleviate other plant limiting conditions within the soil that result from high concentrations of metals, improving plant health indirectly.

• they accumulate N from the compost ,leaf litter ,manure and P from acid phosphatases that release P from organic complexes within the soil.

•  The relationship between seedling growth and the proportion of ectomycorrhizal root tips are positive in high light and negative in low light.

•  Mycorrhizal fungi can also be a key source of water for orchids.

•  it's widely accepted that EM mycelia improve the acquisition of mineral nutrients which are already in solution which they are doing so by means of an external mycelium which may be a physical extension of the basis system.

•  They also act as a sink for C, bind soil particles into soil aggregates, and supply an immediate pathway for translocation of photosynthetically derived C to microsites within the soil to sustain other microbes.

•  the environment within the vicinity of tips to take care of microbial processes and nutrient cycling during drought. The external mycelium may form a big fraction of the entire microbial biomass in forest soils (up to 900 kg ha− 1) but the functioning and regulation of this compartment is still poorly understood.

•  Mycorrhizal benefits can include greater plant yield, and protection from drought stress and pathogens.

•  Hyphal linkages shared by two or more plants may facilitate the transfer of resources during a community, or assist in seedling establishment.

•  Colonization by ectomycorrhizal fungi also increase plant reproduction