Biochemical Changes in Two Barley Genotypes Inoculated With a Beneficial Fungus Trichoderma harzianum Rifai T-22 Grown in Saline Soil

Abstract

One of the most important environmental factors impacting crop plant productivity is soil salinity. Fungal endophytes have been characterised as biocontrol agents that help in plant productivity and induce resistance responses to several abiotic stresses, including salinity. In the salt-tolerant cereal crop barley (Hordeum vulgare L.), there is limited information about the metabolites and lipids that change in response to inoculation with fungal endophytes in saline conditions. In this study, gas chromatography coupled to mass spectrometry (GC–MS) and LC–electrospray ionisation (ESI)–quadrupole–quadrupole time of flight (QqTOF)-MS were used to determine the metabolite and lipid changes in two fungal inoculated barley genotypes with differing tolerance levels to saline conditions. The more salt-tolerant cultivar was Vlamingh and less salt tolerant was Gairdner. Trichoderma harzianum strain T-22 was used to treat these plants grown in soil under control and saline (200 mM NaCl) conditions. For both genotypes, fungus-colonised plants exposed to NaCl had greater root and shoot biomass, and better chlorophyll content than non-colonised plants, with colonised-Vlamingh performing better than uninoculated control plants. The metabolome dataset using GC–MS consisted of a total of 93 metabolites of which 74 were identified in roots of both barley genotypes as organic acids, sugars, sugar acids, sugar alcohols, amino acids, amines, and a small number of fatty acids. LC-QqTOF-MS analysis resulted in the detection of 186 lipid molecular species, classified into three major lipid classes—glycerophospholipids, glycerolipids, and sphingolipids, from roots of both genotypes. In Cultivar Vlamingh both metabolites and lipids increased with fungus and salt treatment while in Gairdner they decreased. The results from this study suggest that the metabolic pathways by which the fungus imparts salt tolerance is different for the different genotypes.

Salinity inhibits seed germination and embryo growth by reducing starch mobilization efficiency in barley

“…Barley, as one of the most salt‐tolerant cereals, may be a pioneer in shifting crop production to saline lands. Therefore, much attention has been paid to breeding and deciphering the underlying mechanism of salt‐tolerant barley varieties (Gupta et al, 2022; Hura, 2020; Jadidi et al, 2022; Jiang et al, 2022; Munns & Tester, 2008). After growing in the solution or sand culture containing NaCl for 3 weeks, barley showed a higher increase of the shoot dry matter than other cereals, including rice ( Oryza sativa ), durum wheat ( Triticum turgidum ssp durum ), and bread wheat ( Triticum aestivum ) (Munns & Tester, 2008).…”