Inducing Tolerance to Abiotic Stress in Hordeum vulgare L. by Halotolerant Endophytic Fungi Associated With Salt Lake Plants

Abstract

A characteristic trait of plants living in harsh environments is their association with fungal endophytes, which enable them to survive under extreme stress. Abiotic stress resistance in agro-ecosystems, particularly in arid and semi-arid regions, can be increased by inoculating these fungal endophytes on plants other than their original hosts. The present study is therefore focused on the possible role of three halotolerant endophytic fungi, i.e., Periconia macrospinosa, Neocamarosporium goegapense, and N. chichastianum, isolated from roots of salt lake plants growing in the central desert of Iran, in alleviating the adverse effects of salinity and drought stresses on barley under greenhouse conditions. To perform this experiment, a randomized block design was applied with three factors: fungi (four levels including three halotolerant endophytic species and control), salinity (three levels including 8, 12, and 16 dS/m), and drought (four levels including 100, 80, 60, 40 percent field capacity). All plants were measured for growth characteristics, chlorophyll concentration, proline content, and antioxidant enzyme activities. A three-way analysis of variance indicated that all three fungal endophytes, to varying extents, induced the barley plants’ resistance to salinity and drought, and their combined effects. Additionally, we found that fungal endophytes were more effective when the barley plants were subjected to higher levels of salinity and drought. Under the stress of salinity and drought, a strong relationship between inoculation of fungal endophytes and enhancement of biomass, shoot length, chlorophyll concentration, proline content, and activity of catalase, peroxidase, and superoxide dismutase was indicated. We discussed that increased root growth, proline content, and antioxidant enzyme activity are the main physiological and biochemical mechanisms causing stress resistance in barley plants inoculated with endophytes. Our research findings illustrate that fungal endophytes have a substantial potential for increasing abiotic stress tolerance in barley plants, which can be applied in agricultural ecosystems.

Fungal endophytes from saline-adapted shrubs induce salinity stress tolerance in tomato seedlings

“…Habitat-adapted microorganisms have been used to enable plants to adapt to biotic and abiotic stresses, enhance growth and increase reproductive success; some plants are unable to survive in their habitats without fungal symbiosis (Redman et al 2002 , Bouzouina et al 2021 , Moghaddam et al 2022 ). Our results are consistent with these findings.…”

“…Endophytes from extreme environments can confer tolerance to biotic and abiotic stresses on crop plants (Redman et al 2011 , Morsy et al 2020 , Mutungi et al 2021 , Moghaddam et al 2022 ). Kenya is home to the East African Rift Valley System, which harbors several saline alkaline lakes (soda lakes) that are characterized by saline and alkaline conditions (Schagerl and Renaut 2016 ).…”

Advances in Identifying the Mechanisms by Which Microorganisms Improve Barley Salt Tolerance

“…Further, inoculation with Siccibacter C2 might alleviate oxidative stress by reducing hydrogen peroxide and malondialdehyde concentrations resulting from salt stress, thereby improving barley salt tolerance [20]. Further, inoculation with P. macrospinosa, N. goegapense, and N. chichastianum all increased the activities of the antioxidant enzymes SOD, CAT, and POX in barley [21]. However, the improvement of barley salt tolerance after inoculation with Azospirillum brasilense could be related to decreased antioxidant enzyme activity that was more effective in the SS rice variety [9].…”

Fungi beyond limits: The agricultural promise of extremophiles

“…On the other hand, three halotolerant endophytic fungal species, namely Periconia macrospinosa , Neocamarosporium goegapense , and N. chichastianum , previously isolated from the roots of plants growing on the shore of a salt lake in the central desert of Iran, mitigated not only saline stress but also drought stress when inoculated into dicot plants (Hosseyni Moghaddam et al., 2021 ) and in barley ( Hordeum vulgare L.) (Hosseyni Moghaddam et al., 2022 ). Similarly, Trichoderma longibrachiatum HL167, a halotolerant rhizospheric strain, alleviated damage caused by salt stress when inoculated into Cowpea plants (Liu et al., 2023 ).…”