UPLC-QTOF-MS metabolomics analysis revealed the contributions of metabolites to the pathogenesis of Rhizoctonia solani strain AG-1-IA

Abstract

To explore the pathogenesis of Rhizoctonia solani and its phytotoxin phenylacetic acid (PAA) on maize leaves and sheaths, treated leaf and sheath tissues were analyzed and interpreted by ultra-performance liquid chromatography-mass spectrometry combined with chemometrics. The PAA treatment had similar effects to those of R. solani on maize leaves regarding the metabolism of traumatin, phytosphingosine, vitexin 2'' O-beta-D-glucoside, rutin and DIBOA-glucoside, which were up-regulated, while the synthesis of OPC-8:0 and 12-OPDA, precursors for the synthesis of jasmonic acid, a plant defense signaling molecule, was down-regulated under both treatments. However, there were also discrepancies in the influences exhibited by R. solani and PAA as the metabolic concentration of zeaxanthin diglucoside in the R. solani infected leaf group decreased. Conversely, in the PAA-treated leaf group, the synthesis of zeaxanthin diglucoside was enhanced. Moreover, although the synthesis of 12 metabolites were suppressed in both the R. solani- and PAA-treated leaf tissues, the inhibitory effect of R. solani was stronger than that of PAA. An increased expression of quercitrin and quercetin 3-O-glucoside was observed in maize sheaths treated by R. solani, while their concentrations were not changed significantly in the PAA-treated sheaths. Furthermore, a significant decrease in the concentration of L-Glutamate, which plays important roles in plant resistance to necrotrophic pathogens, only occurred in the R. solani-treated sheath tissues. The differentiated metabolite levels may be the partial reason of why maize sheaths were more susceptible to R. solani than leaves and may explain the underlying mechanisms of R. solani pathogenesis.

Advances of Metabolomics in Fungal Pathogen–Plant Interactions

“…In addition, this research also revealed the mechanisms of sclerotium formation and mycelium differentiation at the metabolic level [64]. Similar work has also used this method to reveal the infection mechanisms of R. solani [65].…”

Metabolomics as an Emerging Tool for the Study of Plant–Pathogen Interactions

“…This study revealed that the susceptible interaction between the fungal invader and its host is tissue-specific, showing that a broad-host range pathogen can produce selective toxins for attacking specific hosts. Also, it was shown that L-glutamate levels vary among resistant and susceptible tissues in infected plants, indicating that pathogen-and host-manipulation of glutamate metabolism may underlie the ability of plant cells to remain viable to resist necrotrophic pathogenesis [91,106].…”

Strategies to Manage Rice Sheath Blight: Lessons from Interactions between Rice and Rhizoctonia solani

“…Other biologically active molecules produced by R. solani include oxalic acid (OA), 3-methylthiopropionic acid (MTPA), phenylacetic acid (PAA) and its derivatives (Brooks 2007 ; Hu et al 2018 ; Vidhyasekaran et al 1997 ; Yang et al 2014 ). OA produced by necrotrophic pathogens is an essential virulence factor for successful infection.…”