Transcriptomic, Biochemical, and Morphological Study Reveals the Mechanism of Inhibition of Pseudopestalotiopsis camelliae-sinensis by Phenazine-1-Carboxylic Acid

Abstract

Gray blight disease is one of the most destructive diseases of tea plants and occurs widely in the tea-growing areas of the world. It is caused by several fungal phytopathogens, of which Pseudopestalotiopsis camelliae-sinensis is the main pathogen in China. The environmentally friendly antimicrobial, phenazine-1-carboxylic acid (PCA), a metabolite of the natural soil-borne bacteria Pseudomonas spp., can inhibit a range of fungal crop diseases. In this study, we determined that PCA was active against Ps. camelliae-sinensis in vitro. We studied the mode of action of PCA on hyphae using a microscopic investigation, transcriptomics, biochemical methods, and molecular docking. The results of scanning and transmission electron microscopy indicated that PCA caused developmental deformity of mycelia and organelle damage, and it significantly decreased the accumulation of exopolysaccharides on the hyphal surface. The transcriptome revealed that 1705 and 1683 differentially expressed genes of Ps. camelliae-sinensis treated with PCA were up-regulated or down-regulated, respectively, with genes associated with ribosome biogenesis, oxidative phosphorylation, and encoding various proteins of N-glycan biosynthesis being significantly up-regulated. Up-regulation of nine genes related to N-glycan biosynthesis of Ps. camelliae-sinensis in response to PCA treatment was confirmed by reverse transcription qPCR. The enzymatic activity of catalase and superoxide dismutase of hyphae was significantly decreased by PCA treatment. Our results indicated that exposure to PCA resulted in expression changes in oxidoreductase genes, accumulation of reactive oxygen species, and decreased activity of catalase, with concomitant damage to the fungal cell membrane and cell wall.

Phenazine biosynthesis protein MoPhzF regulates appressorium formation and host infection through canonical metabolic and noncanonical signaling function in Magnaporthe oryzae

“…S10). Notably, it is different from previous studies that PCA results in intracellular ROS accumulation in Botrytis cinerea, Xanthomonas oryzae pv oryzae, and Pseudopestalotiopsis camelliaesinensis (Xu et al, 2015;Simionato et al, 2017;Yin et al, 2021); we found that the lower concentration of PCA suppressed host ROS accumulation. In revealing this new function of PCA in host-pathogen interactions, our chemical proteomic analysis revealed that host target proteins of PCA are enriched in the photosynthesis pathway (Fig.…”

Transcriptomic and metabolomic analyses reveal the antifungal mechanism of the compound phenazine-1-carboxamide on Rhizoctonia solani AG1IA

“…These results suggest that to resist the damage PCN inflicts, this pathogen turned on its self-protection mechanisms and enhanced gene expression, which were all related to resistance ( Yu et al., 2011 ; Beis, 2015 ). Moreover, this study also confirmed that PCN was likely a multi-target and multi-process fungicidal compound, which was similar to the phenazine germicidal compounds previously reported, indicating that this pathogen does not easily develop resistance during PCN usage ( Yin et al., 2021 ). Additionally, the R. solani AG1IA stain can secret cell wall-degrading enzymes and toxins to destroy the cell walls of hosts, thereby killing host cells, obtaining nutrients needed for its own growth and development, and assisting its expansion within host ( Chen, 2020 ).…”

Anthocyanins from Malus spp. inhibit the activity of Gymnosporangium yamadae by downregulating the expression of WSC, RLM1, and PMA1

“…cDNA library construction and RNA-sequencing (RNA-seq) were performed using the Huada DNBSEQ platform (Shenzhen, China). Genes with log2 (Fold Change) > 0.5 and an adjusted p -value (padj) < 0.05, as determined by DESeq2, were assigned as DEGs ( Love et al, 2018 ; Yin et al, 2021 ).…”