Quorum Sensing System Affects the Plant Growth Promotion Traits of Serratia fonticola GS2

Abstract

Quorum sensing (QS) enables bacteria to organize gene expression programs, thereby coordinating collective behaviors. It involves the production, release, and population-wide detection of extracellular signaling molecules. The cellular processes regulated by QS in bacteria are diverse and may be used in mutualistic coordination or in response to changing environmental conditions. Here, we focused on the influence of the QS-dependent genes of our model bacterial strain Serratia fonticola GS2 on potential plant growth promoting (PGP) activities including indole-3-acetic acid (IAA) production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, and biofilm formation. Based on genomic and phenotypic experimental data we identified and investigated the function of QS genes in the genome of the model strain. Our gene deletion study confirmed the biological functionality of the QS auto-inducer ( gloI ) and receptor ( gloR ) on potential PGP activities of GS2. A transcriptomic approach was also undertaken to understand the role of QS genes in regulation of genes primarily involved in PGP activities (IAA, ACC deaminase activity, and biofilm formation). Both transcriptomic and phenotypic data revealed that the QS-deletion mutants had considerably less PGP activities, as compared to the wild type. In addition, in vivo plant experiments showed that plants treated with GS2 had significantly higher growth rates than plants treated with the QS-deletion mutants. Overall, our results showed how QS-dependent genes regulate the potential PGP activities of GS2. This information may be helpful in understanding the relationship between QS-dependent genes and the PGP activity of bacteria, which aid in the production of practical bio-fertilizers for plant growth promotion.

Consortium of Plant Growth – Promoting Rhizobacteria Enhances Oilseed Rape (Brassica Napus L.) Growth Under Normal And Saline Conditions

“…Recent studies have indicated that genes involved in plant growth -promoting effects, bio lm formation, plant colonization, and in triggering induced systemic resistance are regulated by QS systems (Jung et al 2017;Zuniga et al 2017). Our results showed that genome of B19 possessed lsr B,C,D,F genes involved in internalizing, phosphorylating and processing of the AI-2, a small signaling molecule in quorum-sensing (QS) (Torres Cerna et al 2019).…”

Use of Acyl-Homoserine Lactones Leads to Improved Growth of Ginseng Seedlings and Shifts in Soil Microbiome Structure

“…A study done by Von Rad and colleagues [54] showed that treatment with oxo-C6-homoserine lactone provided the expression of genes associated with the auxin and cytokinin pathways. Moreover, a study conducted by Jung et al [55] suggested that plant growth promotion affected the plant growth promotion trait of Serratia fonticola GS2, a quorum-sensing bacterial strain through transcriptome observation. In this study, the treated samples generally showed better growth in terms of the parameters used.…”

Serratia spp. as plant growth-promoting bacteria alleviating salinity, drought, and nutrient imbalance stresses

“…have been carried out on plants cultivated under different cultivation conditions. For instance, after inoculation of rice plants with S. glossinae GS2 and S. fonticola GS2, studies conducted in a climate chamber showed a significant increase in plant growth parameters and chlorophyll content ( Jung et al, 2017b , 2020 ). Interestingly, Jung et al (2017a , b) , by liquid chromatography, also showed that the rhizospheric strains S. glossinae GS2 and S. fonticola GS2 are capable of producing quorum-sensing (QS) signaling molecules (N-hexanoyl-L-homoserine lactone and N-octanoyl-L-homoserine lactone) that play an important role in biofilm formation and plant-microbe interactions.…”