Salt tolerance of barley induced by the root endophytePiriformospora indicais associated with a strong increase in antioxidants

Abstract

Summary• The root endophytic basidiomycete Piriformospora indica has been shown to increase resistance against biotic stress and tolerance to abiotic stress in many plants.• Biochemical mechanisms underlying P. indica-mediated salt tolerance were studied in barley (Hordeum vulgare) with special focus on antioxidants. Physiological markers for salt stress, such as metabolic activity, fatty acid composition, lipid peroxidation, ascorbate concentration and activities of catalase, ascorbate peroxidase, dehydroascorbate reductase, monodehydroascorbate reductase and glutathione reductase enzymes were assessed.• Root colonization by P. indica increased plant growth and attenuated the NaCl-induced lipid peroxidation, metabolic heat efflux and fatty acid desaturation in leaves of the salt-sensitive barley cultivar Ingrid. The endophyte significantly elevated the amount of ascorbic acid and increased the activities of antioxidant enzymes in barley roots under salt stress conditions. Likewise, a sustained up-regulation of the antioxidative system was demonstrated in NaCl-treated roots of the salttolerant barley cultivar California Mariout, irrespective of plant colonization by P. indica.• These findings suggest that antioxidants might play a role in both inherited and endophyte-mediated plant tolerance to salinity.

Properties of the halophyte microbiome and their implications for plant salt tolerance

“…Since plants show this response to mycorrhization even before they are treated with high salt concentrations, one can suggest that colonisation of the roots by an AM fungus makes the plants more tolerant to high soil salinity and also to other osmotic stresses. Similar responses have been observed in plants when colonised by the nonmycorrhizal endophyte P. indica where it was proposed as being involved in general abiotic stress tolerance (Baltruschat et al 2008).…”

The Effect of Mycorrhiza Growth and Expression of Some Genes in Barley

“…Chen et al (2007) indicated that the beneficial impacts of mycorrhizal colonization on plant growth could be largely explained by improved P nutrition. On the other hand, Baltruschat et al (2008) found that the root B endophytic basidiomycete Piriformospora indica increase the tolerance against abiotic stress as in many plants. Gryndler et al (2009) concluded that mycelia of AM fungi are influenced by organic matter decomposition via release of the compounds during the decomposition process and also by secondary metabolites produced by microorganisms involved in organic matter decomposition.…”

Enigmatic Sebacinales

“…Rodriguez and Redman (2008) questioned the increase of antioxidant systems induced by P. indica in the host. However, using salt-sensitive and salttolerant cultivars of Hordeum vulgare for colonization experiments with P. indica, Baltruschat et al (2008) suggested that antioxidants may play a role in inherited, as well as in mycobiont-mediated, plant tolerance to salinity. In Brassica campestris ssp.…”