Mechanistic Insights into Arbuscular Mycorrhizal Fungi-Mediated Drought Stress Tolerance in Plants

Abstract

Arbuscular mycorrhizal fungi (AMF) establish symbiotic interaction with 80% of known land plants. It has a pronounced impact on plant growth, water absorption, mineral nutrition, and protection from abiotic stresses. Plants are very dynamic systems having great adaptability under continuously changing drying conditions. In this regard, the function of AMF as a biological tool for improving plant drought stress tolerance and phenotypic plasticity, in terms of establishing mutualistic associations, seems an innovative approach towards sustainable agriculture. However, a better understanding of these complex interconnected signaling pathways and AMF-mediated mechanisms that regulate the drought tolerance in plants will enhance its potential application as an innovative approach in environmentally friendly agriculture. This paper reviews the underlying mechanisms that are confidently linked with plant–AMF interaction in alleviating drought stress, constructing emphasis on phytohormones and signaling molecules and their interaction with biochemical, and physiological processes to maintain the homeostasis of nutrient and water cycling and plant growth performance. Likewise, the paper will analyze how the AMF symbiosis helps the plant to overcome the deleterious effects of stress is also evaluated. Finally, we review how interactions between various signaling mechanisms governed by AMF symbiosis modulate different physiological responses to improve drought tolerance. Understanding the AMF-mediated mechanisms that are important for regulating the establishment of the mycorrhizal association and the plant protective responses towards unfavorable conditions will open new approaches to exploit AMF as a bioprotective tool against drought.

Increased arbuscular mycorrhizal fungal colonization reduces yield loss of rice (Oryza sativa L.) under drought

“…ABA has been considered the abiotic stress hormone by Bahadur et al (2019), and the increase of ABA under drought agrees with their review. Dobra et al (2010) found that ABA increased about 50-80 times in tobacco leaves grown under drought.…”

“…Dobra et al (2010) found that ABA increased about 50-80 times in tobacco leaves grown under drought. Ludwig-Müller (2010) and Bahadur et al (2019) also included data on changes in ABA levels due to mycorrhizal colonization, and both decreases in root ABA (in tomato and the legume (Glycyrrhiza) and increases in ABA (in maize) have been noted. Reduction of ABA in AMF plants has also been reported by Estrada-Luna and Davies (2003) in mycorrhizal Capsicum annuum compared to non-inoculated plants.…”

Drought and Salinity Stress Responses and Microbe-Induced Tolerance in Plants

“…Egamberdiyeva (2007) found that three PGPB isolates Pseudomona alcaligenes PsA15, Bacillus polymyxa BcP26, and Mycobacterium phlei MbP18 could tolerate high temperatures and salt concentrations and have stimulatory effects on nitrogen, phosphorus, and potassium uptake of Z. mays in nutrient-deficient calcisol soil, thus enhancing the ability of the plant to survive in arid and saline soils. Under drought stress, mycorrhizal association with the plants can improve nutrient accumulation via the establishment of extensive hyphal networks and glomalin secretion that facilitate water and nutrient uptake (Bahadur et al, 2019).…”

Prospects of Arbuscular Mycorrhizal Fungi Utilization in Production of Allium Plants

“…The beginning of the 21st century has been characterized by the intensive development of the arbuscular mycorrhizal fungi (AMF) market, suggesting the great economic, ecological, and nutritional impact of this innovative agronomic approach [1]. The reports devoted to AMF application [1][2][3][4][5][6][7][8] have shown the crucial role of these fungi in the development of a sustainable modern agriculture, due to ability of AMF to significantly improve soil structure, nutrient and water availability, plant tolerance to drought, high temperature, salinity, heavy metals pollution and pathogens, and the stimulation of secondary metabolites synthesis resulting in higher crop quality.…”