Arbuscular mycorrhizal symbiosis and alleviation of salinity stress

Abstract

Several environmental factors adversely affect plant growth and development and final yield performance of a crop. Drought, salinity, nutrient imbalances (including mineral toxicities and deficiencies) and extremes of temperature are among the major environmental constraints to crop productivity worldwide. Development of crop plants with stress tolerance, however, requires, among others, knowledge of the physiological mechanisms and genetic controls of the contributing traits at different plant developmental stages. In the past two decades,biotechnology research has provided considerable insights into the mechanism of biotic stress tolerance in plants at the molecular level. Furthermore, different abiotic stress factors may provoke osmotic stress, oxidative stress and protein denaturation in plants, which lead to similar cellular adaptive responses such as accumulation of compatible solutes, induction of stress proteins, and acceleration of reactive oxygen species scavenging systems. Recently, various methods are adapted to improve plant tolerance to salinity injury through either chemical treatments (plant hormones, minerals, amino acids, quaternary ammonium compounds, polyamines and vitamins) or biofertilizers treatments (Asymbiotic nitrogen-fixing bacteria, symbiotic nitrogen-fixing bacteria) or enhanced a process used naturally by plants (mycorrhiza) to minimise the movement of Na+ to the shoot. Proper management of Arbuscular Mycorrhizal Fungi (AMF) has the potential to improve the profitability and sustainability of salt tolerance. In this review article, the discussion is restricted to the mycorrhizal symbiosis and alleviation of salinity stress.