Multi-Omics Analysis Reveals that the Antimicrobial Kasugamycin Potential Targets Nitrate Reductase inDidymella segeticolato Achieve Control of Tea Leaf Spot

Abstract

Due to the lack of effective disease management measures, tea leaf spot, caused by the fungal phytopathogen Didymella segeticola (Q. Chen) Q. Chen, Crous & L. Cai (syn. Phoma segeticola), is an important foliar disease. The important and widely used agricultural antimicrobial kasugamycin (Ksg), produced by the Gram-positive bacterium Streptomyces kasugaensis, effects high levels of control against crop diseases. The results of the current study indicated that Ksg could inhibit the growth of D. segeticola hyphae in vitro with a half-maximal effective concentration (EC50) of 141.18 μg mL-1. Meanwhile, the curative effect in vivo on the pathogen in detached tea leaves also demonstrated that Ksg induced some morphological changes in organelles, septa, and cell walls as observed by optical microscopy and by scanning and transmission electron microscopy. This may indicate that Ksg may disturb biosynthesis of key metabolites, inhibiting hyphal growth. Integrated transcriptomic, proteomic, and bioinformatic analyses revealed that differentially expressed genes or differentially expressed proteins in D. segeticola hyphae in response to Ksg exposure were involved with metabolic processes and biosynthesis of secondary metabolites. Molecular docking studies indicated that Ksg may target nitrate reductase (NR), and microscale thermophoresis assay shown greater affinity with NR, potentially disturbing nitrogen assimilation and subsequent metabolism. The results indicated that Ksg inhibits the pathogen of tea leaf spot, D. segeticola, possibly by binding to NR, disturbing fungal metabolism, and inducing subsequent changes in hyphal growth and development.

Nitrate reductase is required for sclerotial development and virulence of Sclerotinia sclerotiorum

“…Reactive oxygen species (ROS) played important roles in plant immunity (Qi et al, 2017), while SsNR-silenced mutants showed more sensitivity to H 2 O 2 compared to WT resulting in decreased virulence in plants (soybean and rapeseed). Similar results were obtained in the tea leaf spot which is caused by Didymella segeticola, the antimicrobial kasugamycin inhibits the pathogen by binding to NR, disturbing fungal metabolism with changes in hyphal growth and development (Jiang et al, 2022).…”

Evaluation of kasugamycin as a chiral selector in capillary electrophoresis

“…Kasugamycin (KAS) is an agricultural antibiotic produced by streptomycetes that can effectively kill bacteria by interfering with protein synthesis. This antibiotic is widely used for the treatment of many agricultural diseases, 34,35 owing to high efficiency, low toxicity and broad antibacterial spectrum. Structurally speaking, KAS belongs to aminoglycosides, having both an acidic group and basic groups.…”

Zeolitic Imidazole Framework-90-Based Pesticide Smart-Delivery System with Enhanced Antimicrobial Performance

“…As an aminoglycoside antibiotic isolated from Streptomyces kasugaensis , kasugamycin (KSM) has excellent antimicrobial activity against Erwinia amylovora , Aciovorax citrulli , Didymella segeticola , Rhizoctonia solani , Cercospora janseana , and Magnaporthe oryzae [ 23 , 24 , 25 , 26 , 27 ]. Application of KSM before disease occurrence is an effective method to avoid the outbreak of plant diseases in the field.…”