Page 64 - ACCB 2020

Revista de la Asociación Colombiana de Ciencias Biológicas
issn impreso 0120-4173, issn en línea 2500-7459

Abstract

Arbuscular Mycorrhizal Fungi (AMF) are obligate biotrophs living in symbiotic association with roots of plants.
They are among the most widespread soil microorganisms that provide the host plant with nutrients and pathogen
protection. Modern farming practices like frequent tillage, high input inorganic fertilization and pesticide along
changing climatic conditions due to global warming, have huge impacts on AMF colonization, interaction with
plants and on crop productivity. AMF positively affect the plant tolerance to biotic and abiotic stresses, harsh
ecosystems and plant pathogens by altering root structure, exudation, rhizosphere microfl ora, production of anti-
fungals, antibacterials, and competing with pathogens for nutrient uptake. Thus, it plays a signifi cant role in plant
growth, productivity and quality. Further, the effect of a fungicide is varied depending on its mode of action and
the associated AMF species, suggesting that these fungi have a strong potential as a tool for eco-friendly sustai-
nable farming in the present scenario of global warming.

Keywords: Arbuscular Mycorrhizal Fungi(AM Fungi or AMF), Agriculture, Global warming

Introduction culture, it has become critical to identify and evaluate
Mycorrhizal association is one of the pre-eminent eco-friendly options for adapting to climate change and
examples of symbiotic association, which refers to the harsh agricultural practices. In this review we discuss
association of fungi with plant roots. Mycorrhiza are AM fungi symbiosis, their mechanisms and benefi ts in
usually specialized in serving the plant with increased sustainable crop productivity, especially in the present
water and nutrient uptake (Cu, Fe, P, K, and N) and in scenario of global warming, under high stress condi-
return, the plant nourishes the fungus with carbohydrate tions of drought, changing temperature and elevated
formed by photosynthesis. The fungus uses this carbo- levels of CO .
2
hydrate for its extensions and to synthesize glomalin
molecules which is an N-linked glycoprotein that is
composed of N, C, H, O, P, and Fe. It is glue-like and TYPES OF MYCORRHIZAE
hydrophobic which helps in stabilization of soil aggre- Based on the location of fungal hyphae in relation to
gates and also protect soil from desiccation by impro- the root tissues of the plant, Mycorrhizae are classifi ed
ving the water holding capacity of soil. (1-5). They play in two types, Ectomycorrhiza and Endomycorrhiza. En-
a major role in the growth of the plant and its producti- domycorrhiza comprises 3 major groups i. e, Orchid,
vity while also affecting growth-related functions, such Ericoid and Arbuscular mycorrhizae.
as, stomatal conductance, relative water content and leaf
area (6,7). Arbuscular mycorrhizal fungi belong to the Arbuscular mycorrhiza
phylum Glomeromycota which is marked by the for- AM fungi are the most important member of the group
mation of specialized structures called arbuscules (8). Endomycorrhiza, earlier known as Vesicular Arbus-
These fungi are capable of invading the cortical cells of cular Mycorrhizae (VAM) now termed as Arbuscular
the plant roots forming an extensive network of hyphae mycorrhiza (AM) (1). AM fungi form thick-walled res-
to suck nutrients, they also confer resistance to plants ting spores called extramatricular chlamydospores that
against harsh conditions like drought, salinity, stresses, can survive and germinate in unpropitious conditions.
pathogens, etc (9). Agriculture, a major sector of the They form appressoria on the root surface, the hyphae
Indian society is the primary source of livelihood for invade the root and form branches in the cortex. From
a majority of India's population. Varying climatic con- the branches, the intercellular hyphae run longitudinally
ditions and excessive application of agricultural prac- to enter the cortical cells and develop short branched
tices are having a drastic effect on the different forms hyphal structures called arbuscules which help absorb
of agriculture thus hampering a wide range of ecosys- nutrients for plants (10-11). The germ tube disintegra-
tem services. To establish a method of sustainable agri- tes if they do not successfully penetrate the roots of the

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Rev. Asoc. Col. Cienc.(Col.), 2020; 32: 63-76