The Mutualistic Fungus Piriformospora indica Protects Barley Roots from a Loss of Antioxidant Capacity Caused by the Necrotrophic Pathogen Fusarium culmorum

Abstract

Fusarium culmorum causes root rot in barley (Hordeum vulgare), resulting in severely reduced plant growth and yield. Pretreatment of roots with chlamydospores of the mutualistic root-colonizing basidiomycete Piriformospora indica (subdivision Agaricomycotina) prevented necrotization of root tissues and plant growth retardation commonly associated with Fusarium root rot. Quantification of Fusarium infections with a real-time polymerase chain reaction assay revealed a correlation between root rot symptoms and the relative amount of fungal DNA. Fusarium-infected roots showed reduced levels of ascorbate and glutathione (GSH), along with reduced activities of antioxidant enzymes such as superoxide dismutase, ascorbate peroxidase, GSH reductase, dehydroascorbate reductase, and monodehydroascorbate reductase. Consistent with this, Fusarium-infected roots showed elevated levels of lipid hydroperoxides and decreased ratios of reduced to oxidized forms of ascorbate and GSH. In clear contrast, roots treated with P. indica prior to inoculation with F. culmorum showed levels of ascorbate and GSH that were similar to controls. Likewise, lipid peroxidation and the overall reduction in antioxidant enzyme activities were largely attenuated by P. indica in roots challenged by F. culmorum. These results suggest that P. indica protects roots from necrotrophic pathogens, at least partly, through activating the plant's antioxidant capacity.

The chemical inducer, BTH (benzothiadiazole) and root colonization by mycorrhizal fungi (Glomus spp.) trigger resistance against white rot (Sclerotinia sclerotiorum) in sunflower

“…Using two Glomus species in common bean resulted in good effectivity against SS [1]. We also found that the mycorrhiza like endophytic root-colonising fungus Piriformospora indica protects barley roots from damage caused by another necrotrophic pathogen, Fusarium culmorum [12].…”

Piriformospora indica Reprograms Gene Expression in Arabidopsis Phosphate Metabolism Mutants But Does Not Compensate for Phosphate Limitation

“…Secondary metabolites, such as indole-3-acetaldoxime derivatives, hormones, and different defense compounds/pathways control the colonization of roots during Arabidopsis/ P. indica interaction and thus influence root development (Sherameti et al, 2008; Camehl et al, 2011; Hilbert et al, 2012; Nongbri et al, 2012; Bakshi et al, 2015; Matsuo et al, 2015). P. indica also protects the roots by stimulating the antioxidant system under stress, which again influences developmental programs in response to environmental cues and the redox state of the roots (Baltruschat et al, 2008; Vadassery et al, 2009b; Harrach et al, 2013). To what extend root developmental and genetic programs are altered by endophytes such as P. indica is not completely understood.…”

Improvement of Soil Properties, Growth of Cucumber and Protection against Fusarium Wilt by Piriformospora indica and Two Industrial Organic Wastes

“…in barley against F. culmorum and F. graminerarum (Waller et al, 2005;Deshmukh and Kogel, 2007;Harrach et al, 2013), in wheat against F. oxysporum (Moharam et al, 2017), in maize against F. verticillioides (Kumar et al, 2009), in tomato against F. oxysporum (Fakhro et al, 2010;Sarma et al, 2011) and in lentil against F. oxysporum f.sp. lentis (Dolatabadi et al, 2012).…”