A potential biocontrol agent Streptomyces tauricus XF for managing wheat stripe rust

Abstract

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating disease threatening global wheat production. Biocontrol by beneficial microorganisms is considered an alternative to synthetic fungicide applications. This study aimed to investigate the mechanisms involved in the biocontrol of wheat stripe rust by streptomycetes. A streptomycete strain XF, isolated from the rhizospheric soil of peony, was identified as Streptomyces tauricus based on morphological characteristics and phylogenetic analysis. We determined the inhibitory effect of XF on Pst and biocontrol effect on the disease using XF fermentation filtrate (FL) and actinomycete cell suspension (AC). Results revealed that FL inhibited urediniospore germination by up to 99% and rendered a lethality rate of 61.47% against urediniospores. Additionally, crude extract of ethyl acetate phase of FL caused cytoplasm releases from urediniospores and the deformation of germ tubes. Furthermore, histochemical analyses revealed that treatments of plants with AC and FL increased reactive oxygen species, inhibited haustorium formation, and reduced the biomass of Pst in leaves. Electron microscopy showed that XF mycelium was able to colonize the leaf surface. Moreover, gene expression assays revealed that AC and FL treatments induced the expression of a number of pathogenesis-related genes in wheat leaves. Besides, in the greenhouse experiments, the control effects of AC and FL reached 65.48% and 68.25%, respectively. In the field, application of XF fermentation broth significantly reduced the disease indices of stripe rust by 53.83%. These findings suggest that XF is a potential biocontrol agent for managing wheat stripe rust disease.

Effects of Chemical and Biological Fungicide Applications on Sexual Sporulation of Rhizoctonia solani AG-3 TB on Tobacco

“…Similar findings have been reported in other crops, which also demonstrate similar findings. For example, the application of actinomycete XF significantly reduced the disease indices of stripe rust by 53.83% in the field [ 63 ]. Streptomyces pratensis S10 was reported to significantly inhibit the growth of Fusarium graminearum and effectively control wheat scab and decrease deoxynivalenol content [ 27 ].…”

Interplay of plant pathogens and host defenses: Unveiling the mechanisms and strategies for crop protection

“…Biocontrol method: Bacterial endophytes are the potential biocontrol agents for rusts (Kiani et al, 2021). Streptomycetes are found to significantly reduce the stripe rust incidence in wheat (Jia et al, 2023).…”

Beneficial Microorganisms as Bioprotectants against Foliar Diseases of Cereals: A Review

“…In a recent study, Streptomyces tauricus XF, which can colonize the surface of leaves, was isolated from the rhizospheric soil of a peony. It had a biocontrol effect on the rust disease by applying a fermentation filtrate, which resulted in a lethality rate of 61.47% and inhibited the germination of urediniospores by up to 99% by causing the release of their cytoplasm and the deformation of the germ tube [ 164 ]. The generation and germination rate of urediniospores were decreased by the hyperparasite Cladosporium cladosporioides isolated from Pst taupe-colored uredinia, and the color of the uredinia changed from yellow to taupe [ 165 ].…”