Abstract
There are some bacteria which can grow and multiply at the cost of living fungal biomass. They can potentially utilize fungi as a source of nutrients to forage over them. Such phenomenon is known as bacterial mycophagy, however, its mechanistic insights need to be explored to identify the molecules involved in mycophagy for potential utilization in controlling various fungal diseases. Recently we have demonstrated that a rice-associated bacteria Burkholderia gladioli strain NGJ1 exhibits mycophagous ability on several fungi, including Rhizoctonia solani, the necrotrophic fungal pathogen causing sheath blight disease in rice. We hereby describe our validated and efficient methods used to study B. gladioli strain NGJ1-R. solani interactions. These methodologies would be useful for designing assays to study the confrontation between bacteria and fungi which in turn enable discovery of novel antifungal molecules from such bacteria.
Keywords: Burkholderia gladioli, Bacterial mycophagy, Bacterial-fungal interaction, Rhizoctonia solani, Sheath blight disease
Background
Rhizoctonia solani is an important plant pathogenic fungi with a wide range of hosts. It causes sheath blight disease in rice; the second most devastating fungal disease of rice after Blast disease (Fisher et al., 2012; Ghosh et al., 2014; Ghosh et al., 2017). In wake of developing control methods of sheath blight disease of rice, we isolated a bacterium with a broad spectrum antifungal activity from rice seedling. Based upon the rDNA and draft genome sequencing, the bacterium had been identified as Burkholderia gladioli strain NGJ1 (Jha et al., 2015). Beside antifungal property, we observed that the NGJ1 has the ability to forage over fungi and exhibit mycophagous ability on R. solani as well as various other tested fungi. Upon interaction with R. solani mycelia, NGJ1 growth was drastically enhanced. The NGJ1 imparted cell death response in R. solani and caused disintegration of fungal mycelia. We further established that the bacteria utilize type III secretion system to deliver a prophage tail-like protein (Bg_9562) to feed on R. solani (Swain et al., 2017).
Materials and Reagents
Equipment
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Data analysis
All the information about data processing, statistical tests, details of replicates and independent experiments was already included in original research paper (Swain et al., [2017]. A prophage tail-like protein is deployed by Burkholderia bacteria to feed on fungi. Nature Communications. 404(8). doi:10.1038/s41467-017-00529-0).
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Acknowledgments
The research funding from DBT, Government of India and core research grant from National Institute of Plant Genome Research, India to support the GJ lab are gratefully acknowledged. RK and SG acknowledge fellowship from CSIR and IT, SKY, JD acknowledges fellowship from DBT, Govt. of India. The authors declare no conflict of interest.
References
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