Screening, Identification, and Optimization of Fermentation Conditions of an Antagonistic Endophyte to Wheat Head Blight

Abstract

Fusarium Head Blight (FHB, scab) is a destructive fungal disease that causes extensive yield and quality losses in wheat and other small cereals. Biological control of FHB is considered to be an alternative disease management strategy that is environmentally benign, durable, and compatible with other control measures. In this study, to screen antagonistic bacteria with the potential to manage FHB, 113 endophytes were isolated from the stems, leaves, panicles, and roots of wheat. Among them, six strains appeared to effectively inhibit Fusarium graminearum growth and one isolate, XS-2, showed a highly antagonistic effect against FHB. An in vitro antagonistic test of XS-2 on wheat heads confirmed that XS-2 could suppress the disease severity of FHB. The 16S rDNA sequence analysis revealed that XS-2 is a strain of Bacillus amyloliquefaciens. Antagonistic spectrum analyses showed that XS-2 had antagonistic effects against two and four types of cotton and fruit tree pathogens, respectively. The fermentation condition assays showed that glucose and peptone are the most suitable nutrient sources for XS-2, and that the optimal pH value and temperature for fermentation were 7.4 and 28 °C, respectively. Our study indicates that XS-2 has a good antagonistic effect on FHB and lays a theoretical foundation for the application of the strain as a biological agent in the field to control FHB.

Wine Lactic Acid Bacteria with Antimicrobial Activity as Potential Biocontrol Agents against Fusarium oxysporum f. sp. lycopersici

“…Due to the problems inherent in the use of chemical pesticides, there is a tendency to reduce and restrict the use of pesticides, which is materialized in the progressive prohibition of the most toxic products [9]. To all this we must add the growing awareness of the population in relation to this problem and, consequently, the growing rejection of consumers towards foods treated with these products [4,10].…”

Pantoea agglomerans SWg2 colonizes mulberry tissues, promotes disease protection and seedling growth

“…SWg2 strain was isolated from the surface-disinfected root of a healthy mulberry sampled from the mulberry experimental field of Southwest University, Chongqing, China (29°48′47′′ N, 106°24′30′′ E) (Zhang et al, 2013). This strain possessed significant antagonistic activity against Pseudomonas syringae pv.…”

“…mori by the inhibitory halo assay in an agar plate. And then, it was identified to be Pantoea agglomerans by morphological features, physiological and biochemical characteristics and molecular methods (Zhang et al, 2013). It has been stored at −80°C in 15% glycerol.…”

“…This strain SWg2 of P. agglomerans (GenBank, KC783460) is an antagonistic endophytic bacterium against P. syringae pv. mori, isolated from healthy mulberry roots (Zhang et al, 2013). Pantoea agglomerans also known as Erwinia herbicola (Löhnis) Dye are members of the E. herbicola-Enterobacter agglomerans cluster belonging to the Enterobacteriaceae, which are ubiquitous in nature, inhabiting soil, water, plants, animals and humans (Graham and Hodgkiss, 1967;Gavini et al, 1989).…”

Bacterial Endophytes of Spring Wheat Grains and the Potential to Acquire Fe, Cu, and Zn under Their Low Soil Bioavailability

“…The understanding of the microbial diversity and function in complex plant–soil environments has increased significantly as a consequence of the application of next-generation sequencing (NGS) methods [ 31 , 32 ]. It is well recognized that every plant species possesses its own endo-microbiome that works commensally or beneficially for the host [ 33 , 34 , 35 ]. Endophytic bacteria serve as rich sources of phytohormones and diverse secondary metabolites with a wide spectrum of biological activities [ 24 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ].…”