**2. Arbuscular mycorrhizal fungi**

Arbuscular mycorrhizae fungi (AMF), are beneficial organisms and play an important part in plant nutrition and performance. The interaction of AMF symbiosis with positively charged bivalent (Ca2+, Fe2+) and trivalent cations (Al3+) improves immobile absorption and insoluble phosphate ions in soil [6]. The ability of AMF to evolve exterior hyphae networks that can increase external area approximately 40 fold and expose soil volume for absorption of nutrients by generating enzymes or releasing organic compounds is the primary function in this mutualism [7]. AMF can produce phosphatises to disintegrate phosphate from organic phosphorus containing compounds, increasing productivity in hard environments (deficiency of phosphorous). Extra radical hyphae are thought to be important in terms of ammonium absorption, mobilization of fixed microelements viz. Cu and Zn, and other cations from the soil like potassium, Magnesium, iron and calcium. Reports reveal that AMF promotes plant nutrition, when used as biofertilizer and hampers plant hormone balance, which regulates plant development (bioregulators) and lessens the influence of external pressures that is bio protector. This boosts biomass and yield while causing changes in several quality indicators [8]. AM fungi develop intimate association with host plants through intracellular structures called arbuscules in cortical cells of roots thus referring as symbiotic biotrophs. AMF are soil inhibiting fungi with the potential to boost nutrient absorption in plants and resilience to a variety of inanimate stressors [9]. Furthermore these depend on metabolic products of host produced during photosynthesis for completion of their life cycle, hence referred as obligate biotrophs. AMF provides growth benefits to plants through two ways viz., by improving water and mineral nutrient absorption from the surrounding soil and by protecting them from fungal infections [10]. As a

result, AMF are beneficial endosymbionts that contribute to plant productivity and ecological function. They are critical for sustainable agricultural production [11].
