Nitric Oxide Production by Necrotrophic Pathogen Macrophomina phaseolina and the Host Plant in Charcoal Rot Disease of Jute: Complexity of the Interplay between Necrotroph–Host Plant Interactions

Abstract

M. phaseolina, a global devastating necrotrophic fungal pathogen causes charcoal rot disease in more than 500 host plants. With the aim of understanding the plant-necrotrophic pathogen interaction associated with charcoal rot disease of jute, biochemical approach was attempted to study cellular nitric oxide production under diseased condition. This is the first report on M. phaseolina infection in Corchorus capsularis (jute) plants which resulted in elevated nitric oxide, reactive nitrogen species and S nitrosothiols production in infected tissues. Time dependent nitric oxide production was also assessed with 4-Amino-5-Methylamino-2′,7′-Difluorofluorescein Diacetate using single leaf experiment both in presence of M. phaseolina and xylanases obtained from fungal secretome. Cellular redox status and redox active enzymes were also assessed during plant fungal interaction. Interestingly, M. phaseolina was found to produce nitric oxide which was detected in vitro inside the mycelium and in the surrounding medium. Addition of mammalian nitric oxide synthase inhibitor could block the nitric oxide production in M. phaseolina. Bioinformatics analysis revealed nitric oxide synthase like sequence with conserved amino acid sequences in M. phaseolina genome sequence. In conclusion, the production of nitric oxide and reactive nitrogen species may have important physiological significance in necrotrophic host pathogen interaction.

Nitric oxide as a developmental and metabolic signal in filamentous fungi

“…The correlation of a transient NO burst with disease spread was also observed in the compatible lily— Botrytis elliptica interaction, where the accumulation of NO in infected cells was concurrent with extensive mycelial proliferation (van Baarlen, Staats & van Kan, ). Similarly, NO overproduction in the susceptible jute‐ Macrophomina phaseolina interaction was coincident with NO‐derived compound accumulation localized in the vascular bundle region harboring invaded mycelia and micro‐sclerotia (Sarkar, Biswas, Ghosh & Ghosh, ). Although the necrotroph‐induced generation of NO in plant cells could correlate with increased disease resistance, the NO burst induced by necrotrophic pathogens B. cinerea (Asai & Yoshioka, ; Floryszak‐Wieczorek et al, ) or Sclerotinia sclerotiourm (Perchepied et al, ) was an early and transient event (Mur, Carver & Prats, ), which did not affect necrotrophic growth afterward.…”

The necrotrophic fungus Macrophomina phaseolina induces oxidative stress-associated genes and related biochemical responses in charcoal rot susceptible sorghum genotypes

“…For instance, NO is claimed to confer resistance against certain necrotrophic fungal pathogens (Asai et al 2010; Perchepied et al 2010). On the contrary, an accumulation of NO in host tissue correlated with enhanced disease susceptibility was observed in the compatible jute- M. phaseolina (Sarkar et al 2014) and lily- Botrytis elliptica interactions (van Baarlen et al 2004). Agreeing with the latter phenomenon, we observed an NO burst in susceptible sorghum stalk tissues (Tx7000, BTx3042) after M. phaseolina inoculation.…”

“…For example, the infection, colonization, and suppression of host defenses by the model necrotrophic fungus, Botrytis cinerea is due to the production of high levels of ROS (van Kan 2006; Choquer et al 2007). Macrophomina phaseolina generates a flux of NO during the infection process of jute plant (Sarkar et al 2014).…”

“…Although some necrotrophic fungi use their own ROS and reactive nitrogen species (RNS) as virulence factors during infection and colonization (Shetty et al 2008; van Kan 2006; Choquer et al 2007; Sarkar et al 2014), necrotroph infection-associated up-regulation of host-derived ROS and RNS is poorly described. To investigate the differentially expressed genes associated with host-derived oxidative stress, the global transcriptome profiles of charcoal rot resistant (SC599) and susceptible (Tx7000) sorghum lines were characterized in response to M. phaseolina inoculation using RNA-Seq.…”

Exogenous ascorbic acid is a pro-nitrant in Arabidopsis thaliana

“…The content of ONOOin the root tips was detected using dihydrorhodamine (DHR) staining (Sarkar et al 2014). Roots were incubated in 10 µM DHR solution prepared in Tris-HCl (10 mM, pH 7.4), and were washed twice with Tris-HCl buffer.…”