Alleviation of salt-induced adverse impact via mycorrhizal fungi inEphedra aphyllaForssk

Abstract

The current investigation was carried out to examine the role of arbuscular mycorrhizal fungi (AMF) in alleviating adverse effects of salt stress in Ephedra aphylla. The plants were exposed to 75 and 150 mM sodium chloride (NaCl) stress with and without application of AMF. Salt stress caused significant decrease in chlorophyll and carotenoid contents; however, the application of AMF restored the pigments content in salt-affected plants. Proline, phenols, and lipid peroxidation were increased with increasing concentration of NaCl, but lower accumulation has been reported in plants treated with AMF. NaCl stress also showed increase in different antioxidant enzymes activities (catalase, ascorbate peroxidase, peroxidase, glutathione reductase, and superoxide dismutase), and further increase was observed in plants treated with AMF. The nutrient uptake, Na + and Na/K ratio increased and potassium and phosphorus were decreased with increasing concentration of NaCl in the present study. However, the colonization with AMF significantly increased K + and P and reduced Na + uptake. It is concluded that presown soil treatment with AMF reduced severity of salt stress in E. aphylla through alterations in physiological parameters, antioxidants and uptake of nutrients.Keywords: arbuscular mycorrhizal fungi; Ephedra aphylla; salinity; antioxidant enzymes; ion accumulation IntroductionDesertification or the disappearance of vegetation from arid land is an increasing problem worldwide including Saudi Arabia (SA). Abiotic stress leads to loss of natural resources such as plant biomass, biodiversity, and imparts a great role in global warming. Among the abiotic stresses, salinity is one of the main factor that contributes to desertification of arid lands. Soil salinization has become a great challenge for rehabilitation of range lands and plant productivity (Alqarawi et al. 2014). Salinity not only reduces yield of plants but also disrupts the ecological balance of the area. Stress tolerance of plants is a complex phenomenon involving changes at morphological, physiological, biochemical, and molecular levels and are undoubtedly the most important response of plants to the adverse environmental conditions (Rasool, Hameed, et al. 2013;Shaheen et al. 2013;Ahmad et al. 2014;Alqarawi et al. 2014). Salinity causes nutritional disorders in plants which lead to deficiencies of several nutrients and drastically increasing Na + levels in the plant cells (Iqbal & Ashraf 2013). The adverse effects of salt stress causes imbalance in the synthesis of endogenous plant growth regulators (PGR), hence a number of changes take place which disturb growth and physiological processes such as plant cell permeability, respiration, energy transport, and photosynthesis in plant cells (Ahmad et al. 2012;Iqbal & Ashraf 2013). Moreover, the salt stress also causes oxidative stress through the generation of reactive oxygen species (ROS), such as hydrogen peroxide, superoxide ions, singlet oxygen, and hydroxyl radical. These ROS cause deleterious effects on mitoc...

Arbuscular Mycorrhizal Fungi Improve the Antioxidative Response and the Seed Production of Suaedoideae Species Suaeda physophora Pall Under Salt Stress

“…AMF significantly increased aboveground biomass of S. physophora under different salt conditions (Table 2), which is consistent with some previous studies (Zhang et al, 2012;Alqarawi et al, 2014;Zhao et al, 2015). Moreover, the aboveground biomass of S. physophora increased with the increase of NaCl concentration in the control.…”

“…This implies that the enhancement of SOD and POD scavenge reactive oxygen species (ROS) to protect S. physophora from cellular oxidative damage, which is an important protective mechanism against cellular oxidative damage under salt stress (Ahmad et al, 2012). The inoculation of the AMF significantly improved the POD activity of S. physophora, which is consistent with previous studies on Ephedra aphylla (Alqarawi et al, 2014), tomatoes (He et al, 2007), wheat (Talaat and Shawky, 2014) and cowpeas (Abeer et al, 2015). Moreover, the AMF also increased the activity of SOD in the leaves of S. physophora, which corresponds with previous studies (Wu, 2011;Li et al, 2012).…”

“…These species structures can form mutualistic associations with most land plant species and obtain carbon (C) from their plant partners in exchange for mineral nutrients (Zheng et al, 2014). AMF can not only improve plant growth but also protect their host plants from drought stress, salt stress and nutrient depletions (Morte et al, 2001;Alqarawi et al, 2014). Some plant species are unable to live without AMF in some extreme environments (Pennisi, 2004) and thus play a key role in maintaining the functionality and stability of ecosystem (Aliasgharzadeh et al, 2001;Rodriguez and Redman, 2008).…”

Arbuscular mycorrhizal fungi enhance growth, physiological parameters and yield of salt stressed Phaseolus mungo (L.) Hepper

“…Increase in antioxidant enzyme activity with increase in salinity is confirmed by Hashem et al (2015). At all the salinity levels used, there was a higher peroxidase activity in the treatment inoculated with mycorrhizal fungi, which support the findings of Alqarawi et al (2014) and Abd Allah et al (2015). Estimates of phosphatase activity in plants help to assess phosphorus metabolism in mycorrhizal plants as this enzyme is present in the vacuoles of AM hyphae (Tisserent et al 1993).…”

Effects of arbuscular mycorrhizal fungi on photosynthesis and chlorophyll fluorescence of maize seedlings under salt stress

“…Salinity is one of the major environmental factors which can impede natural growth, development and metabolism (Hashem et al, 2016;Alqarawi et al, 2014). Among all the cell functions restrained by salt stress, photosynthesis is the most sensitive physiological processes to salinity, increased salt concentrations in soil can inhibit photosynthetic enzymes activity, and cut down the content of photosynthetic pigments (Sheng et al, 2008), moreover, salt stress may bring much negative effect on stomatal conductance and intercellular CO 2 concentrations, then depressing photosynthesis (Elhindi et al, 2017).…”