Mycorrhizal fungi under biotic and abiotic stress

Abstract

Mycorrhizal fungi are associated with host plant roots which complement and augment plant growth, productivity, and immunity; nevertheless, current work by scientists shows that mycorrhiza also provoke so-called induced systemic tolerance (IST) to abiotic and biotic stresses. As we discuss here, the mycorrhiza also upsurge nutrient uptake and transport from soils, thus reducing the need for chemical fertilizers and avoiding the buildup of nitrates and phosphates in the agricultural soils. A decrease in fertilizer use would reduce the effects of contamination of water from fertilizer run off and leaching lead to savings for farmers. Abiotic stresses (such as soil salinity, drought, heat, cold, mineral deficiency) have become main threats to the universal agricultural production. These stress in alone and/or in combination control the plant growth, development, maturity, and productivity by causing physiological disorders, ion toxicity, and nutritional and hormonal disparities. Some precious soil microbes like mycorrhizal fungi inhabit the rhizosphere and develop a symbiotic and mutualistic relationship with the roots of most host plant species. Mycorrhiza can considerably enhance resistance of host plants to varied abiotic and biotic stresses. In this chapter, we highlight the importance of mycorrhizal fungi alleviation of various stresses and their beneficial effects on plant growth expansion and production. Though these stresses can negatively affect the mycorrhizal fungi, there are many reports which exhibit better growth, performance, and production of mycorrhizal plants under stress conditions. These positive consequences are explained by increased host plant nutrition, higher potassium, nitrogen and phosphate in plant tissues and a better osmotic modification by buildup of well-matched solutes such as proline, glycine betaine, or soluble sugars. Mycorrhizal inoculated plants also increase photosynthetic, physiological, biological, and water use efficiency under various stresses.