Pseudomonas sp. ST4 produces variety of active compounds to interfere fungal sexual mating and hyphal growth

Abstract

Sexual mating of compatible sporida is essential for Sporisorium scitamineum to form dikaryotic mycelia and then cause infection on sugarcane. Our previous work identified a Pseudomonas sp. ST4 from a soil sample, which showed a promising biocontrol potential by inhibiting the mating of S. scitamineum sporida and hyphal growth. In this study, we set to isolate the active compounds from Pseudomonas sp. ST4 through solid fermentation. High-performance liquid chromatography (HPLC) separation coupling with bioassay showed that Pseudomonas sp. ST4 produced a range of antimicrobial compounds. Two of the major components were purified following acetate extraction, silica gel and HPLC separation. Nuclear magnetic resonance (NMR) and liquid chromatography-mass spectrometry (LC-MS) analysis identified these active compounds are 4-hydroxybenzaldehyde and indole-3-carbaldehyde respectively. Further analysis showed that the former compound only inhibited the hyphal growth of the fungus at a concentration of 3 mM, while the latter interfered the fungal sexual mating at a concentration of 0.6 mM and affected hyphal growth at a concentration of 2 mM. Treatment of corn plants with 3 mM indole-3-carbaldehyde significantly inhibited corn smut infection, with a control rate up to 94%. Further analysis of the structure and activity relationship revealed that indole has a much stronger inhibitory activity against the fungal sexual mating than indole-3-carbaldehyde. The results from this study provide new agents for control and prevention of the sugarcane smut disease, and the active compounds could also be used to probe the molecular mechanisms of fungal sexual mating.

Quorum Quenching in a Novel Acinetobacter sp. XN-10 Bacterial Strain against Pectobacterium carotovorum subsp. carotovorum

“…Plant diseases are affected by three interdependent factors, including synchronized activity of regulation networks, virulence factors, and infection processes of bacterial pathogens [ 36 ]. Overuse of antibiotics, widely used and recognized as the most effective antimicrobial agents for curing diseases caused by pathogenic bacteria in current production applications, has led to environmental pollution and high occurrence of bacterial resistance [ 37 ]. Numerous bacteria serving as biocontrol agents to manage plant diseases have been verified [ 27 , 31 , 35 , 38 ].…”

The potential use of the Penicillium chrysogenum antifungal protein PAF, the designed variant PAFopt and its γ‐core peptide Pγopt in plant protection

“…several antifungal cyclic peptides; Lee and Kim, 2015), inhibit the fungal growth (e.g. 4‐hydroxybenzaldehyde; Liu et al , 2020), or sexual mating (e.g. indole‐3‐carbaldehyde; Liu et al , 2020).…”

“…4‐hydroxybenzaldehyde; Liu et al , 2020), or sexual mating (e.g. indole‐3‐carbaldehyde; Liu et al , 2020). In spite of these advantages only few of them have been successfully developed into commercial fungicides.…”

Indole-3-Carboxylic Acid From the Endophytic Fungus Lasiodiplodia pseudotheobromae LPS-1 as a Synergist Enhancing the Antagonism of Jasmonic Acid Against Blumeria graminis on Wheat

“…ST4, Streptomyces sp. CT37, Aeromicrobium ponti LGMB491, Janthinobacterium lividum , Clitocybe nuda LA82, Angelica sinensis callus, and Marinomonas sp., has inhibitory effects on the growth of Sporisorium scitamineum , Ustilago maydis , Candida albicans ATCC 10231, Staphylococcus aureus , and Batrachochytrium dendrobatidis JEL215, on zoospore germination of Phytophthora capsici PCM81, on neuroinflammation, and on the biofilm formation of Vibrio cholerae O1, respectively ( Brucker et al., 2008 ; Chen et al., 2012 ; Rajalaxmi et al., 2016 ; Gos et al., 2017 ; Zhou et al., 2017 ; Liu et al., 2020 ; Fang et al., 2020 ). However, other reports about indole-3-carbaldehyde did not indicate its antimicrobial activity against pathogens.…”