Commercial cucumber “Straight eight” (Cucumis sativus) seeds (Isla, Brazil) were surface disinfected by immersion in 70% ethanol for 1min, followed by 10min in 1% sodium hypochlorite. The seeds were then rinsed five times in sterile deionized water. The seeds were distributed into Petri dishes containing 1% water agar and incubated in the dark at 25°C for 3days. Each germinated seed was sown in a 300ml (volume) pot filled with sterilized vermiculite and sand in a 1:1 (v/v) ratio. The experiment consisted of two treatments: the non-inoculated control, and SC5 inoculation. The inoculation consisted of soaking the germinating seeds for 1h in an overnight grown bacterial suspension (TSB, 28°C, 150rpm) adjusted to OD₆₀₀=0.3 in sterile 0.03M MgSO₄, followed by the direct application of 3ml of a bacterial suspension (OD₆₀₀=0.3) into the root-shoot junction of germinated plants. Six plants were used for each treatment. The assay was conducted under laboratory conditions with an average temperature of 25°C and a 12h photoperiod. The plants received 10ml Hoagland’s nutrient solution (Hoagland and Arnon, 1950) whenever necessary, and were harvested 3weeks after inoculation. The plant roots and shoots were excised and dried for 3days at 60°C in order to record dry weights on an analytical scale.

Salt stress is one the major inducers of ACC and ethylene production by several plant species, which ultimately leads to plant growth inhibition (root and shoot development, overall biomass; Tao et al., 2015). The fine-tuning of ACC and ethylene levels under salt stress conditions is therefore of importance for increased plant salt stress resistance (Riyazuddin et al., 2020). Since P. thivervalensis SC5 presented both ACC deaminase activity, salt stress resistance and overall plant growth promotion abilities, we hypothesized that this strain could be useful for increasing cucumber plant salt stress resistance. Cucumber is known for its high sensitivity to salt stress (Gamalero et al., 2010). Based on this hypothesis, P. thivervalensis SC5 was tested for its ability to help salt-sensitive cucumber plants to overcome some of the deleterious effects of salt stress (100mmol/l NaCl).

The preparation of the experiment (seed germination, inoculation, and pots) was conducted as described above (see Section “Cucumber Plant Growth Promotion Assay UnderLaboratory Conditions”).

The experiment consisted of four treatments: non-inoculated control (normal conditions); P. thivervalensis SC5 inoculation (normal conditions); non-inoculated control+100mmol/L NaCl (salt stress conditions); P. thivervalensis SC5 inoculation +100mmol/L NaCl (salt stress conditions). Six plants were used for each treatment. In the initial 5days of growth the plants received 5ml Hoagland’s nutrient solution whenever necessary (dried top layer of vermiculite and sand). After this period, stress conditions were imposed (to the respective salt receiving treatments) by applying 10ml Hoagland’s nutrient solution containing 100mmol/L NaCl 4days per week. The non-inoculated control and P. thivervalensis SC5 inoculation treatments (normal conditions) received 10ml Hoagland’s nutrient solution 4days per week.

The greenhouse experiment (average temperature 26.9°C) was conducted in the Universidade Federal de Santa Catarina, Florianópolis, Brazil. About 3weeks after sowing, cucumber plants were harvested, washed with tap water, and root and shoot lengths (SLs) were measured. The plants were then dried at 60°C and root and shoot dry weights were measured.

Pseudomonas thivervalensis SC5 reduces nitrate to produce N (gas) and ammonia, indicating that the dissimilatory nitrate reduction and denitrification pathways are active in this strain. These results are consistent with the presence of the genes responsible for the dissimilatory nitrate reduction (nas) and denitrification (nir, nar, and nor) pathways, as well as several genes involved in nitrate, nitrite, and ammonia transport (three amtB genes) in the SC5 genome (Supplementary Table S2). Additionally, genes involved in urea and allophanate transport and degradation, namely the ureABC cluster responsible for urease production and, atzF, encoding the allophanate hydrolase, were also found (Supplementary Table S2).

Two nitronate monooxygenase genes (npd) involved in the oxidative denitrification of toxic nitronates and nitroalkanes to their corresponding aldehydes and nitrites; and three copies of the azoR gene, encoding azoreductase were found to be present in the genome (Supplementary Table S2), and may account for strain’s SC5 ability to degrade nitro-containing xenobiotics.

Strain SC5 possesses the complete set of genes responsible for the assimilatory sulfate reduction pathway (cis genes) and several genes involved in sulfate transport (sulP, cysPUWA). The taurine transport and taurine dioxygenase genes (tauD, three copies; Supplementary Table S3) involved in the catabolism of taurine; sulfone and sulfonate transport and degradation genes involved in the degradation of sulfones (sfnG) and alkanesulfonates (ssuABCD); and dddP and dmoA genes involved in the catabolism of dimethlysulfonioproprionate and dimethylsulfide were also found in the genome, suggesting an ability to modulate plant and soil sulfur metabolism.

The genome of strain SC5 contains the pyrroloquinoline quinone (pqq) operon and glucose dehydrogenase genes involved in the production of gluconate, a major organic acid involved in the solubilization of mineral phosphate and other compounds such as ZnO. In addition, genes encoding enzymes involved in organic phosphate solubilization, such as an extracellular phytase, several alkaline phosphatases, and some components of the phosphonate C-P lyase system were found in the genome of strain SC5 (Supplementary Table S4). The strain SC5 extracellular phytase (CE140_04710) presents some similarity with Bacillus subtilis extracellular 3-phytase involved in the catabolism of phytate a common plant metabolite found in plant tissues and soils, that serves as a storage source for phosphorus and inositol (Zeng et al., 2011). Two copies of the genes encoding the phosphate transport system (pstABCS) were also detected in the genome (Supplementary Table S4).

Overall, the data obtained indicates that P. thivervalensis SC5 participates in N, S, and P soil cycles through several enzymatic activities, thus, increasing the availability of several key nutrients that are indispensable for plant growth.

Pseudomonas thivervalensis SC5 and its relatives, P. thivervalensis LMG 21626^T (=BS3779) and P. thivervalensis PITR2, synthesize siderophores. Recently, Matthijs et al. (2016) identified two siderophores produced by strain LMG 21626^T, as pyoverdine (PYO_thi) and histocorrugatin, and characterized the genomic regions responsible for their biosynthesis. The genomic regions containing the pvd and hcsABCDEFGHIJKL genes were detected in the chromosome of P. thivervalensis SC5 (Supplementary Table S5), suggesting the production of pyoverdine (PYO_thi) and histocorrugatin by this strain. In addition to pyoverdine and histocorrugatin biosynthetic clusters, one other region containing a Non-Ribosomal Peptide Synthase (NRPS) and other siderophore biosynthesis related genes was detected in the strain SC5 chromosome (Supplementary Table S5). This genomic region (CE140_5180-5260) contained both isochorismate synthase (CE140_05240) and isochorismate pyruvate lyase (CE140_05235) gene homologs, which are involved in the production of SA, suggesting the production of a SA-containing siderophore. Moreover, the NRPS associated with this cluster (CE140_5180, CE140_5185) showed some homology (~43–46%) to NRPS’s from the coelibactin biosynthetic cluster of Streptomyces coelicolor A3(2). BLAST analysis revealed that this NRPS cluster is somewhat rare, being only detected in 20 other sequenced Pseudomonas strains (mostly synxantha, simiae, libanensis, and azotoformans).

Iron and iron complex (including siderophore-iron complex) transport genes are extremely abundant in the genome sequence of strain SC5 (Supplementary Table S5), suggesting that iron acquisition and metabolism plays an important role in strain SC5 physiology and ecology.

Strain SC5 was able to grow in the presence of high salt concentrations, which is consistent with the presence of multiple genes involved in the biosynthesis, metabolism and transport of osmoprotectants in its genome (Supplementary Table S6). In this regard, strain SC5 possesses the genes for the biosynthesis of compatible solutes such as proline (proABC), glutamate (gltBD), glutamine (seven glnA genes), carnitine (bodG, lcdH), N-acetylglutaminylglutamine amide (NAGGN; ngg), glycine-betaine (betABC), glycogen (glg), trehalose (two treS genes, treYZ), ectoine, and hydroxyectoine (doeABCD), as well as several of the transporters of these compounds (proP, proXWV, betT, opuABCD, thuEFGK, and ehuABCD; Supplementary Table S6). In addition, several genes involved in the transport of sodium and chloride (nhaAB, yfbK, glnT, and putP) were detected in the genome.

The SC5 genome also contains several genes involved in the biosynthesis, metabolism, and transport of polyamines and 4-aminobutyrate (GABA; Supplementary Table S7), which also play a role in salt stress resistance (Schiller et al., 2000). The strain SC5 chromosome contains the speA, aguA, aguB, and speC genes involved in putrescine biosynthesis; the hss, cansD, and nspC genes involved in homospermidine, carboxynorspermidine, and spermidine biosynthesis; as well as several genes involved in polyamine degradation (puuABCD, spuC, and prr) and conversion to GABA.

The results obtained indicate that P. thivervalensis SC5 can acquire, synthesize, accumulate, and metabolize wide range of osmolytes and polyamines that are known to play a role in osmotic stress tolerance, as well as in plant colonization and plant growth promotion. For example, the induction of osmotic stress and the presence of compatible solutes increased the plant colonization and biocontrol activities of P. fluorescens EPS62e (Bonaterra et al., 2007). The production of trehalose by the PGPB Pseudomonas sp. UW4, played an important role in the protection of tomato plants against salt stress (Orozco-Mosqueda et al., 2019). The biosynthesis of polyamines plays a role in plant growth promotion activities of plant-associated bacteria (Chen et al., 2017).

Pseudomonas thivervalensis SC5 chromosomal DNA contains the genes involved in the synthesis of flagella (flg, fli) and pilus (pil, cpa) systems involved in bacterial motility (Supplementary Table S8). The genome also harbors 38 genes encoding methyl-accepting chemotaxis proteins as well as multiple copies of chemotaxis related genes cheA, cheB, cheD, cheV, cheY, cheR, motA, and motB (Supplementary Table S8).

The SC5 genome harbors several genes involved in bacterial attachment to plant tissues, including the type IV pilus and fimbriae biosynthesis genes, the tight adherence (Tad) export apparatus and Flp (fimbrial low molecular-weight protein) pili, the bcs cellulose production operon, the alg operon responsible for alginate production, and several other gene clusters potentially involved in exopolysaccharide formation (Supplementary Table S8).

Pseudomonas thivervalensis SC5 harbors an increased number of genes involved in the response to oxidative stress, including four katE genes encoding catalase; katG, encoding a catalase-peroxidase; two sod genes that encode Fe-Mn family superoxide dismutases; two ahpC genes that encode an alkyl hydroperoxide reductase; a peroxiredoxin Q/BCP bcp gene; tpx, encoding an atypical 2-Cys peroxiredoxin; a cytochrome c peroxidase gene; three gpx genes encoding glutathione peroxidase; four non-heme chloroperoxidases (cpo); three osmC genes that encode a lipoyl-dependent peroxiredoxin; a dye-decolorizing peroxidase gene homolog, and a superoxide oxidase, cybB, gene. A gene cluster involved in the production of an aryl polyene, possibly involved in the protection against reactive oxygen species (ROS; Cimermancic et al., 2014), was also detected in the genome of P. thivervalensis SC5 (Supplementary Table S9). This data indicates that P. thivervalensis SC5 possess a significant ability to detoxify several ROS, which may impact several aspects of plant growth as well as plant-microbe interactions. For example, plants produce increased levels of ROS under stressful conditions (e.g., salt stress) that impact plant growth (Huang et al., 2019). The plant defense response against bacteria is mostly mediated by ROS (Bolwell and Wojtaszek, 1997). Ultimately, beneficial bacteria able to overcome the inhibitory effects of ROS are better able to colonize and protect plant hosts against stress (Kim et al., 2000; Alquéres et al., 2013; Tiepo et al., 2020).

Genomic analysis revealed the presence of several carbohydrate (sugars, sugar alcohols, and sugar acids) catabolism and transport genes in strain SC5 chromosomal DNA (Supplementary Table S10). These included genes involved in the catabolism of sugars such as glucose (through gluconate), fructose, ribose, xylose, galactose, mannose, sucrose, maltose, trehalose, and beta-glucosides; sugar alcohols such as glycerol, mannitol, galactictol/sorbitol, and inositol; and sugar acids such as glycolate, D-gluconate, L-gulonate, D-fructuronate, D-mannonate, D-lactate, galactarate, glycerate, D-glucarate, L-talarate, and D-galactonate degradation. The SC5 genome also contains the genes involved in the TCA cycle (citrate, fumarate, succinate, aconitate, isocitrate, and malate metabolism), the glyoxylate bypass (glyoxylate catabolism), and the metabolism of several organic acids such as acetate, oxaloacetate, formate, malonate, tartrate, propionate, and butyrate (Supplementary Table S11).

Strain SC5 also contains several genes involved in the transport and metabolism of amino acids and peptides, as well as opines (Supplementary Table S12). Opines are compounds synthesized from the condensation of amino acids with ketoacids or sugars, and have been linked to the colonization abilities of rhizobia and Agrobacterium (Murphy et al., 1995; Dessaux et al., 1998). The genome of strain SC5 contains the mocC gene involved in the catabolism of rhizopine (Galbraith et al., 1998), several opine oxidase gene homologs (ooxAB) involved in octopine degradation, as well as the inositol/myo-inositol transport system and homologs of the octopine transport system, indicating the strain SC5 ability to catabolize opines and modulate its effects on plant-microbe interactions.

The P. thivervalensis SC5 genome contains the ech, vdh, and fcs gene cluster that encodes the enzymes enoyl-CoA hydratase/aldolase, vanillin dehydrogenase, and feruloyl-CoA synthetase, involved in the catabolism of hydroxycinnamic acids such as ferulic acid (conversion to vannilate), p-coumaric acid (conversion to 4-hydroxybenzoate) and caffeic acid (conversion to protocatechuate). A mhpA gene homolog encoding the 3-(3-hydroxyphenyl)propanoate hydroxylase involved in 3-hydroxycinnamic acid (m-coumaric acid) catabolism, and the hpa operon encoding a 4-hydroxyphenylacetate 3-monooxygenase system involved in p-coumaric acid oxidation, are also present in the chromosome of strain SC5. Moreover, the vannilate catabolism genes, vanAB, responsible for the conversion of vannilate to protocatechuate; the pobA gene responsible to the conversion of 4-hydroxybenzoate to protocatechuate; and the pca operon containing the genes responsible for the conversion of protocatechuate to acetyl-CoA (via 3-oxoadipate) were also detected (Supplementary Table S13), consistent with the presence of a complete degradation pathway for hydroxycinnamic acids in strain SC5.

The ability to use hydroxycinnamic acids as carbon sources may play a role in P. thivervalensis SC5 rhizospheric colonization activities, as well as in soil and plant health maintenance by decreasing the long-term accumulation of these toxic allelochemical compounds (Turner and Rice, 1975; Batish et al., 2008; Singh et al., 2014; Ferro et al., 2015).

Two NADPH-dependent curcumin reductase genes (curA) were also detected in the SC5 genome (Supplementary Table S13) and may be involved in strain SC5 ability to metabolize the plant polyphenolic and antibacterial compound curcumin.

A gene encoding a Dyp type peroxidase enzyme (CE140_09525) with 84.5% identity to the P. fluorescens Pf-5 DyP1B enzyme, involved in the oxidation of lignin substrates (Rahman Pour and Bugg, 2015), was found in the genome of P. thivervalensis SC5, suggesting that this strain has the ability to degrade lignin.

Genomic analysis also revealed the presence a polyphenol oxidase/laccase encoding gene, responsible for the oxidation of several phenolics; calA and calB genes encoding the coniferyl-alcohol dehydrogenase and coniferyl-aldehyde dehydrogenase enzymes, respectively, involved in the catabolism of the monolignol coniferyl-alcohol and the respective coniferyl aldehyde (Supplementary Table S13); a 2,4'-dihydroxyacetophenone dioxygenase responsible for the degradation of 2,4'-dihydroxyacetophenone to 4-hydroxybenzoate; and the catechol 2,3-dioxygenase enzyme responsible for the catabolism of catechol. Coniferyl-alcohols and hydroxycinnamic acids are components of plant lignin, and 2,4'-dihydroxyacetophenone and catechol are known breakdown products of lignin. Overall, the acquired data suggests that strain SC5 may modulate plant lignin levels, which are an important determinant of plant growth, stress resistance, and defense (Liu et al., 2018).

SC5 genomic analysis led to the identification of a cluster (CE140_08155-08295) containing several genes that present a high level of identity to the naringenin degradation genes of Herbaspirillum seropedicae SmR1 (Marin et al., 2013). In addition, three quercetin 2,3-dioxygenase genes, involved in the catabolism of the flavonoid quercetin were also detected in the genome of P. thivervalensis SC5 (Supplementary Table S13).

Flavonoid degradation is a trait described in several Pseudomonas species (Rao and Cooper, 1994; Pillai and Swarup, 2002) that may play an important role in the modulation of soil and plant flavonoid concentrations. The degradation of flavonoids leads to the production of p-coumaric acid, caffeic acid, phenylacetic acid (PAA), p-hydroxybenzoate, and protocatechuate (B-ring products); and phloroglucinol, phloroglucinol carboxylate, resorcinol, and oxaloacetate (A-ring products; Rao and Cooper, 1994; Pillai and Swarup, 2002), which are then channeled to the TCA cycle. Most of the genes involved in these pathways were found in the SC5 genome, indicating the ability to completely use several flavonoids as carbon sources, a trait likely associated with the colonization activities of the bacterium.

The acdS gene (CE140_07955) encoding ACC deaminase, as well as the acdR gene (CE140_07960) that encodes a leucine-responsive protein known to regulate acdS gene expression (Li and Glick, 2001), were found in the genome of P. thivervalensis SC5 (Supplementary Table S14). The AcdS and AcdR proteins present a high identity (97.6 and 86.4%, respectively) to those of the efficient ACC deaminase-producing PGPB, Pseudomonas sp. UW4. Moreover, analysis of the P. thivervalensis SC5 acdS gene and its nearby regulatory regions indicated that this gene is stably present in the SC5 chromosome (with no transposase or mobile genetic elements in its vicinity), indicating a long-term acquisition and evolution of the acdS gene in strain SC5. The acdS gene is known to be positively selected in most legume-rhizobia symbiosis (Nascimento et al., 2018b); hence, the presence of a stable acdS gene in P. thivervalensis SC5 suggests that this strain has evolved a long term mutualistic interaction with plant hosts, where the expression of ACC deaminase plays a valuable and positive role.

In addition to acdS, strain SC5 also contains a tlpQ gene homolog (CE140_07340), involved in the chemotactic response to ethylene, which acts as an attractant to several plant-associated Pseudomonas strains (Kim et al., 2007); and several genes involved in polyamine (putrescine, spermidine) production and transport (Supplementary Table S14). Bacterial spermidine inhibits plant ethylene biosynthesis, leading to an increase in plant growth promotion (Xie et al., 2014).

A tryptophan 2-monooxygenase gene (iaaM) homolog, possibly involved in the biosynthesis of indole-3-acetamide (IAM), and several amidase genes (amiE, yafV) that may convert IAM to IAA, were found in the genome of P. thivervalensis SC5 (Supplementary Table S14), thus suggesting that strain SC5 produces IAA trough the IAM pathway (Duca and Glick, 2020). The production of IAA trough the IAM pathway has also been described in other beneficial Pseudomonas strains, such as Pseudomonas chlororaphis O6 (Dimkpa et al., 2012).

Curiously, two feaB genes encoding the phenylacetaldehyde dehydrogenase enzyme involved in phenylacetate (PAA) production were identified in the genome of strain SC5 (Supplementary Table S14), thus suggesting its ability to synthesize PAA. PAA is also considered an auxin with significant impact in plant growth (Cook, 2019). Moreover, PAA production by beneficial plant-associated bacteria also acts as an inducer of the plant defense response, leading to increased plant resistance against fungal pathogens (Sumayo et al., 2013; Akram et al., 2016).

The genome of strain SC5 contains several genetic elements involved in the production and transformation of cytokinins (CKs; Supplementary Table S14), such as the miaA, miaB, and miaE genes involved in the production of N6-(Δ2-isopentenyl)adenosine, 2-methylthio-N6-(dimethylallyl)adenosine, and 2-methylthio-cis-ribozeatin, respectively. The SC5 genome also contain several genes encoding RNAses, which can be involved in the dissociation of tRNA-associated CKs. Additionally, two log genes, which encode the cytokinin riboside 5'-monophosphate phosphoribohydrolase responsible for the conversion of CK-nucleotides to free-base forms (Samanovic et al., 2015); and the xanthine dehydrogenase genes, xdhABC, responsible for the biotransformation of CKs (Taylor et al., 2006), were also found in the genome sequence of P. thivervalensis SC5 (Supplementary Table S14).

The abundance of genetic elements involved in the production and transformation of CKs suggests that P. thivervalensis SC5 is able to synthesize CKs, a trait also found in other Pseudomonas strains (de Salamone et al., 2001; Karnwal and Kaushik, 2011; Großkinsky et al., 2016). Moreover, P. fluorescens G20-18 CK production abilities also play an important role in the biocontrol of P. syringae infection in Arabidopsis (Großkinsky et al., 2016); hence, the production of CKs by P. thivervalensis SC5 may impact not only its plant growth promotion activities but also its biocontrol activities.

Several genes involved in the production of SA, namely, one isochorismate synthase (pchA), which converts chorismate into isochorismate (the building block for SA biosynthesis) and two isochorismate-pyruvate lyase gene homologs (pchB), which are responsible for the transformation of isochorismate to SA, were identified in the SC5 chromosomal DNA (Supplementary Table S14). The pchA and one copy of the pchB gene were found in an operon responsible for siderophore biosynthesis (described above), suggesting a role in the synthesis of a SA-containing siderophore. One additional copy of pchB (pchB2) was found in a genomic region not related to siderophore production; pchB2 (CE140_03015) is clustered with a gene encoding an isochorismatase-like protein. These results suggest the production of SA by P. thivervalensis SC5, a trait that has also been described in other Pseudomonas spp. (Bakker et al., 2014).

Salicylic acid is one of the main plant hormones involved in plant defense responses, and, consequently, has important functions in regulating plant-microbe interactions (Lebeis et al., 2015). Moreover, SA also plays an important role in plant growth and abiotic stress resistance (Rivas-San Vicente and Plasencia, 2011; Khan et al., 2015). The production of SA by P. thivervalensis SC5 may play an important role in its ability to interact with plant hosts, to promote plant growth as well as in its biocontrol activities against pathogens.

ANTISMASH analysis revealed the presence of several gene clusters involved in the biosynthesis of antagonistic secondary metabolites in the genome of strain SC5. These included a 2,4-diacetylphloroglucinol (DAPG) biosynthesis cluster constituted by the phlHGF and phlACBDE genes; a cluster involved in hydrogen cyanide (HCN) production (hcnABC); a gene cluster involved in the biosynthesis of a fragin homolog; three gene clusters involved in bacteriocin production, and one cluster involved in the production of a lantipeptide (Supplementary Table S15).

Strain SC5 DAPG biosynthesis cluster (phlACBDE and phlHGF) presents high identity to the functional DAPG biosynthesis gene cluster of P. thivervalensis PITR2 (~99% identity; Keel et al., 1996; Molina et al., 2003), and other studied biocontrol Pseudomonas strains such as P. kilonensis F113 (~93% identity; Redondo-Nieto et al., 2013; Vacheron et al., 2018), P. brassicacearum BIM B-446 (~93% identity; Mandryk-Litvinkovich et al., 2017), P. brassicacearum 3Re2-7 (~93% identity; Nelkner et al., 2019), P. brassicacearum LBUM300 (~93% identity; Lanteigne et al., 2012; Novinscak et al., 2016), among others. Moreover, BLAST analysis revealed that the hcnABC gene cluster of P. thivervalensis SC5 also presented high identity to the functional hcnABC genes of several HCN-producing Pseudomonas, including P. thivervalensis PITR2 (~99% identity; Ramette et al., 2003), P. brassicacearum 3Re2-7 (~92% identity; Nelkner et al., 2019) and P. brassicacearum LBUM300 (~92% identity; Lanteigne et al., 2012; Novinscak et al., 2016).

Several genes involved in acyl homoserine lactone catabolism (pvdQ, quiP) and homoserine lactone efflux were detected in the genome of strain SC5 (Supplementary Table S15), suggesting the ability to modulate quorum-sensing signals, a trait of relevant importance for biocontrol activities (Alymanesh et al., 2016).

Based on the increased prevalence of genes involved in the biosynthesis of antagonistic secondary compounds it was decided to test P. thivervalensis SC5 for its ability to antagonize the phytopathogens B. cinerea (fungal) and P. syringae DC3000 (bacterial). These assays revealed that P. thivervalensis SC5 inhibited the growth of both pathogens, confirming the active production of pathogen antagonistic traits (Figure 3). The obtained results indicate that strain SC5 presents the ability to act as a biocontrol agent, a trait also observed in its close relative, P. thivervalensis PITR2, a bacterium isolated from a disease suppressive soil known to actively produce the antifungal metabolites DAPG and HCN [73].