Effect of a Bacillus subtilis strain on flax protection against Fusarium oxysporum and its impact on the root and stem cell walls

Abstract

In Normandy, flax is a plant of important economic interest because of its fibres. Fusarium oxysporum, a telluric fungus, is responsible for the major losses in crop yield and fibre quality. Several methods are currently used to limit the use of phytochemicals on crops. One of them is the use of plant growth promoting rhizobacteria (PGPR) occurring naturally in the rhizosphere. PGPR are known to act as local antagonists to soil-borne pathogens and to enhance plant resistance by eliciting the induced systemic resistance (ISR). In this study, we first investigated the cell wall modifications occurring in roots and stems after inoculation with the fungus in two flax varieties. First, we showed that both varieties displayed different cell wall organization and that rapid modifications occurred in roots and stems after inoculation. Then, we demonstrated the efficiency of a Bacillus subtilis strain to limit Fusarium wilt on both varieties with a better efficiency for one of them. Finally, thermo-gravimetry was used to highlight that B. subtilis induced modifications of the stem properties, supporting a reinforcement of the cell walls. Our findings suggest that the efficiency and the mode of action of the PGPR B. subtilis is likely to be flax variety dependent.

Transcriptomic profiling of susceptible and resistant flax seedlings after Fusarium oxysporum lini infection

“…One of the most serious threat to flax cultivation are fusarioses with Fusarium oxysporum f. sp. lini (Fol) being the most dangerous Fusarium species due to its high specificity to this plant [1]. It penetrates into the plant through the root system and then spreads using vascular bundles.…”

Overview and Management of the Most Common Eukaryotic Diseases of Flax (Linum usitatissimum)

“…Bacillus subtilis subsp. spizizenii strain ATCC 6633 also has a biocontrol potential against this fungus, and its efficiency to reduce Fusarium wilt of flax has been validated under controlled conditions [18]. European seed testing protocol [53] imposes the detection of Fusarium spp.…”

The Extracellular Lipopeptides and Volatile Organic Compounds of Bacillus subtilis DHA41 Display Broad-Spectrum Antifungal Activity against Soil-Borne Phytopathogenic Fungi

“…have shown great potential in controlling Fusarium wilt in different crops [ 17 ]. Notably, B. subtilis , B. velezensis , Bacillus tequilensis , and Bacillus licheniformis have demonstrated the ability to protect watermelon, cucumber, tomato, flax, and banana from Fusarium wilt [ 12 , 16 , 18 , 19 , 20 , 21 ]. For example, B. velezensis F21 significantly suppressed watermelon Fusarium wilt, reducing the disease incidence in the greenhouse (80%) and in the field (66%) [ 19 ], resulting in improved crop yield and quality in an eco-friendly and cost-effective manner.…”