Arbuscular mycorrhizae: natural modulators of plant-nutrient relation and growth in stressful environments.

The human population is increasing by 0.96% annually and is estimated to reach from 7.3 to 9 billion in 2050 and 11 billion in 2100. The world's agriculture is under pressure to produce more food and ensure food security. On the other hand, around 40% of the cultivable land is already degraded due to various factors including urbanization, soil sealing, soil acidification, salinization, soil erosion, and contamination. Arbuscular mycorrhizal fungi (AMF) constitute a unique group of root obligate symbiont that exchange mutual benefits with about 90% of terrestrial plants and represents a key link between plants and soil mineral nutrients. Literature is scanty on the studies on massive inoculation of AMF in food crops in agronomic settings, and thereby achieving efficient uptake and minimization of the major soil nutrients, eventually meeting our food demand under increasing and inevitable stressed environments. Given above, this review aimed to (i) introduce agricultural soil-contamination, and the relation of soil microbiome with the health of soils and plants; (ii) briefly overview AMF; (iii) highlight AMF role as a bioinoculant, and enhancer of efficient uptake and loss-minimization of nutrients; (iv) appraise literature available on AMF role in the regulation of growth and nutrition mainly in vegetable, horticultural crops and fruit trees; (v) enlighten the role and major mechanisms underlying AMF-mediated regulation of plant growth and nutrition under major biotic and abiotic stresses; (vi) highlight AMF role in the minimization of greenhouse gas emissions; and (vii) list major aspects so far unexplored in the current context.