cDNA Transcriptome of Arabidopsis Reveals Various Defense Priming Induced by a Broad-Spectrum Biocontrol Agent Burkholderia sp. SSG

Abstract

Burkholderia sp. SSG is a potent biological control agent. Even though its survival on the leaf surface declined rapidly, SSG provided extended, moderate plant protection from a broad spectrum of pathogens. This study used Arabidopsis Col-0 and its mutants, eds16-1, npr1-1, and pad4-1 as model plants and compared treated plants with non-treated controls to elucidate whether SSG triggers plant defense priming. Only eds16-1 leaves with SSG became purplish, suggesting the involvement of salicylic acid (SA) in SSG-induced priming. cDNA sequencing of Col-0 plants and differential gene expression analysis identified 120 and 119 differentially expressed genes (DEGs) at 6- and 24-h post-treatment (hpt) with SSG, respectively. Most of these DEGs encoded responses to biotic and abiotic stimuli or stresses; four DEGs had more than two isoforms. A total of 23 DEGs were shared at 6 and 24 hpt, showing four regulation patterns. Functional categorization of these shared DEGs, and 44 very significantly upregulated DEGs revealed that SSG triggered various defense priming mechanisms, including responses to phosphate or iron deficiency, modulation of defense-linked SA, jasmonic acid, ethylene, and abscisic acid pathways, defense-related gene regulation, and chromatin modification. These data support that SSG is an induced systemic resistance (ISR) trigger conferring plant protection upon pathogen encounter.

Amphibian skin bacteria display antifungal activity and induce plant defense mechanisms against Botrytis cinerea

“…When comparing our results with other transcriptional reports of previously characterized biocontrol agents, we noticed a difference in the expressed genes in the presence of C32I, compared to Bacillus valezensis FBZ42 , Pseudomonas fluorescences SS01 , and Burkholderia sp. SSG ( Figure 9 ) ( van de Mortel et al., 2012 ; Tzipilevich et al., 2021 ; Kong et al., 2022 ). When we compared the transcriptional changes induced by C32I only few genes are shared with the other BCAs, suggesting that, even though all the analyzed BCAs have a biocontrol activity, transcriptional regulation by C32I triggers defense induction mechanisms distinct from other microorganisms.…”

“…Interestingly, a comparison of transcriptomic data from our results with other biocontrol agents, such as Bacillus valezensis FBZ42, Pseudomonas fluorescences SS01 , and Burkholderia sp. SSG , shows transcriptomic differentiation, indicating that each strain elicits a plant-specific response and may be involved in ISR activation ( van de Mortel et al., 2012 ; Tzipilevich et al., 2021 ; Kong et al., 2022 ). Based on this evidence, we can infer that the early activation of the plant defense system could contribute to an effective inhibition of B. cinerea .…”

Molecular mechanism of endophytic bacteria DX120E regulating polyamine metabolism and promoting plant growth in sugarcane

“…Polyamine is also an intermediate signaling molecule in ACC signaling. Some beneficial microbes are ethylene regulators by affecting ACC deaminase, which reduces ethylene levels while promoting plant growth and defense ( Kong et al., 2022 ). ACC deaminase lowers ethylene levels by converting ACC precursor into α-ketobutyrate and ammonia ( Mukherjee et al., 2020 ).…”

Characterization of the Soil Bacterial Community from Selected Boxwood Gardens across the United States

“…First, Burkholderiales , one of the most dominant orders identified in this study, is known to have species and strains with biological control and other beneficial activities. Specifically, Burkholderia strain SSG isolated from boxwood has been demonstrated to be highly effective as a biocontrol agent against boxwood blight [ 65 ] and other diseases caused by a variety of pathogens including bacteria, oomycetes, other fungi, and one virus [ 66 ], as well as acting as a biofertilizer and plant defense inducer [ 65 , 67 ]. These broad-spectrum biological activities are supported by the many antibiosis genes and clusters on the Burkholderia sp.…”