Characterization of antifungal metabolite phenazine from rice rhizosphere fluorescent pseudomonads (FPs) and their effect on sheath blight of rice

Abstract

We have shown, the outcome of antifungal activity of phenazine derivatives which is produced by fluorescent pseudomonads (FPs) for the control of sheath blight of rice. A total of 50 fluorescent pseudomonads (FPs) were isolated from rice rhizosphere. Off which, 36 FPs exhibited antagonistic activity against Rhizoctonia solani , Macrophomina phaseolina , Fusarium oxysporum , Alternaria alternata and Sclerotium rolfsii up to 70–80% compared to control by dual culture method. BOX-PCR analyses of antagonistic isolates indicated that two phylogenetic group, where group I consisted of 28 isolates and eight isolates belongs to group II. Among 36 FPs, a total of 10 FPs revealed that the presence of phenazine derivatives on thin layer chromatography (TLC), which is coincided with that of authentic phenazine with R f value 0.57. Similar to TLC analysis, antibiotic encoding gene phenazine-1-carboxamide (PCN) was detected in 10 FPs by PCR analysis with respective primer. Among, PCN detected isolates of FPs, a significant biocontrol potential possessing isolate designated as VSMKU1 and it was showed prominent antifungal activity against R. solani and other tested fungal pathogens. Hence, the isolate VSMKU1 was selected for further studies. The selected isolate VSMKU1 was identified as Pseudomonas aeruginosa by 16S rDNA sequence analysis. The antifungal metabolite phenazine like compound produced by VSMKU1 was confirmed by UV, FT-IR and HPLC analysis. The phenazine compound from VSMKU1 significantly arrest the growth of R. solani compared to carbendazim by well diffusion method. The detached leaf assay showed remarkable inhibition of lesion height 80 to 85% by the treatments of culture (VSMKU1), cell free culure filtrate and phenazine like compound compared to control and other treatments was observed in detached leaves of rice. These results emphasized that VSMKU1 isolate can be used as an alternative potential biocontrol agent against sheath blight of rice, instead of using commercial fungicide such as validamycin and carbendazim which cause environmental pollution and health hazards.

Pseudomonas fluorescens Showing Antifungal Activity against Macrophomina phaseolina, a Severe Pathogenic Fungus of Soybean, Produces Phenazine as the Main Active Metabolite

“…A mutation in the gltA gene of the P. chlororaphis subgroup from a native isolate from Argentina was recently reported as a determinant inductor of a phenotypic change associated with phenazine production, which is essential for the bacterial antifungal activity [ 38 ]. In addition, phenazine derivatives were also produced by fluorescent pseudomonads (FPs) proposed for the control of sheath blight of rice [ 39 ].…”

Partial purification and characterization of 2, 4-diacetylphloroglucinol producing Pseudomonas fluorescens VSMKU3054 against bacterial wilt disease of tomato

“…Antimicrobial compounds produced by FPs were involved for the control of various bacterial and fungal pathogens. Pseudomonas spp ( Ayyadurai et al, 2006 ), P. aeruginosa MML2212 ( Shanmugaiah et al, 2010 ), P. corrugate GFBP 5454 and P. mediterranea GFBP 5447 ( Strano et al, 2017 ), Pseudomonas sp VSMKU4036 ( Varatharaju et al, 2020 , Ansari et al, 2021 ), and P. aeruginosa VSMKU1 ( Nithya et al, 2020 ) are significantly control the growth of different bacterial and fungal plant pathogens by the secretion of diffusible compounds like 2,4-diacetylphloroglucinol (2,4-DAPG), phenazine-1-carboxamide (PCN). Pholoroglucinol assist and act as a signal molecule to induce the expression of pyrrolnitrin biosynthesis.…”

“…In recent days, fluorescent pseudomonads (FPs) have drawn much attention worldwide for the control of fungal and bacterial pathogens ( Haas and Défago, 2005 , Couillerot et al, 2009 , Mohammed et al, 2020 ). The current interest has been increased using beneficial microorganisms such as Pseudomonas spp ( Sakthivel and Gnanamanickam, 1987 , Shanmugaiah et al, 2010 , Nithya et al, 2020 , Basu et al, 2021 ), Bacillus spp ( Shanmugaiah et al, 2008 , Arasu et al, 2016 , Rais et al, 2017 , Khan et al, 2020 , Al-Dhabi et al, 2020 ), Streptomyces spp ( Prabavathy et al, 2006 , Harikrishnan et al, 2014 ) and Trichoderma spp ( Mathivanan et al, 2005 ., Shanmugaiah et al, 2009 , Sood et al, 2020 ). Among different, beneficial microorganisms, FPs is a predominant rhizospheric microorganism and easily adapts various environmental conditions.…”

“…Among different, beneficial microorganisms, FPs is a predominant rhizospheric microorganism and easily adapts various environmental conditions. Because, FPs have the ability to control plant disease by two different mechanisms such as direct and indirect ( Compant et al, 2005 , Nithya et al, 2020 ). FPs are produced wide range antimicrobial metabolites such as Phenazine ( Shanmugaiah et al, 2010 , Nithya et al, 2020 ), 2,4-diacetylphloroglucinol (DAPG) ( Velusamy et al, 2006 , Zhou et al, 2012 ), pyrrolnitrin ( De Souza and Raaijmakers, 2003 ), pyoluteorin ( Hu et al, 2005 ), Hydrogen cyanide ( Defago and Haas, 1990 ) and lytic enzymes ( Zhou et al, 2012 , Mohammed et al, 2020 ).…”

“…Similarly, phlA , phlB , and phlC are involved in the conversion of MAPG to 2,4-DAPG ( Almario et al, 2017 , Zhao et al, 2020 ). The economically important soil-borne fungal pathogens such as Fusarium oxysporum, R. solani, M. phaseolina, and S. rolfsii were successfully controlled by Phenazine derivatives ( Nithya et al, 2020 ), 2, 4-DAPG ( Velusamy et al, 2006 , Zhou et al, 2012 ) producing Pseudomonas spp. Many potential antimicrobial compounds obtained from Pseudomonas spp and its mechanism in in vitro and in vivo conditions are not explored properly.…”