Current developments in arbuscular mycorrhizal fungi research and its role in salinity stress alleviation: a biotechnological perspective

Abstract

Arbuscular mycorrhizal fungi (AMF) form widespread symbiotic associations with 80% of known land plants. They play a major role in plant nutrition, growth, water absorption, nutrient cycling and protection from pathogens, and as a result, contribute to ecosystem processes. Salinity stress conditions undoubtedly limit plant productivity and, therefore, the role of AMF as a biological tool for improving plant salt stress tolerance, is gaining economic importance worldwide. However, this approach requires a better understanding of how plants and AMF intimately interact with each other in saline environments and how this interaction leads to physiological changes in plants. This knowledge is important to develop sustainable strategies for successful utilization of AMF to improve plant health under a variety of stress conditions. Recent advances in the field of molecular biology, "omics" technology and advanced microscopy can provide new insight about these mechanisms of interaction between AMF and plants, as well as other microbes. This review mainly discusses the effect of salinity on AMF and plants, and role of AMF in alleviation of salinity stress including insight on methods for AMF identification. The focus remains on latest advancements in mycorrhizal research that can potentially offer an integrative understanding of the role of AMF in salinity tolerance and sustainable crop production.

Arbuscular mycorrhizal association in Conocarpus erectus (Combretaceae) in mangroves from Yucatán, México

“…The substrate conditions in the three sites analyzed in the present study are considered hypersaline (FAO 1994) and can cause damage through the toxicity of the ions themselves or by osmotic stress to both the plants and the AMF (Juniper & Abbott 2006, Munns & Tester 2008, Evelin et al 2009). However, it has been reported that the AMF are capable of providing benefits to their hosts in conditions of elevated salinity (Kumar et al 2015). In this study, arbuscules were recorded within the roots of C. erectus in all three sites, indicating that the association is functional (Espinosa-Victoria 2000) under the entire range of salinities analyzed.…”

Towards a Sustainable Agriculture: Strategies Involving Phytoprotectants against Salt Stress

“…AMF symbiosis has been found to enhance salinity tolerance in different host plants, such as cucumber, lettuce, tomato, maize, acacia and citrus [32][33][34][35][36][37]. AMF increase absorption of soil water through the mycelium and mobilization in the plant, enhance soil-root contact, reduce the deleterious effects of phytotoxic ions on the integrity of the plasmatic membrane and cell organelles, change phytohormone balance, increase antioxidant defenses (both enzymatic and non-enzymatic) and promote the expression of salt stress-related genes [37][38][39][40][41]. In addition, AMF may increase root hydraulic conductivity at low water potential [42], promote and change root system architecture, and enhance stomatal conductance by improving the gas exchange capacity [31,37,39,43].…”

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“…Algunas investigaciones se han referido a la importancia que la simbiosis AMF-planta ha tenido en los sistemas agroproductivos debido al cúmulo de evidencias que han permitido constatar beneficios en las especies hospedantes (Field et al, 2015) tales como conferir tolerancia a la sequía (Ortiz et al, 2015), salinidad (Kumar et al, 2015a;Dar et al, 2018) -Dzul et al, 2011;Preciado et al, 2011).…”