Bioprospecting endophytic Diaporthe species associated with Pachystachys lutea (Acanthaceae) with antagonistic effect against Sclerotinia sclerotiorum

Endophytic microorganisms live inside the plant tissues symptomless. These microorganisma may present antagonistic activity against phytopathogens or produce metabolites with antifungal activity. We aimed to evaluate in vitro antagonism and competitive interactions between endophytic fungi of Diaporthe species and Sclerotinia sclerotiorum. We also carried out in vitro screening of antifungal activity of metabolic extracts of the two endophytes against the pathogen. The antagonism was performed by the paired-culture and two promising antagonists strains were selected for metabolic extraction from the fermented culture. Metabolic extracts were obtainment using two different organic solvents (Ethyl Acetate and Hexane) and their antifungal activity was carried out using the agar diffusion test. The in vitro antagonistic index ranged from 22.1 to 59.5%, with Diaporthe sp. PL03 (59.1%), D. schini PL40 (59.5%), D. infecunda PL63 (41.8%), D. anacardii PL64 (56.8%), with inhibition by mycelial contact. The endophytes PL01 (28.6%) and PL43 (28.5%), both D. anacardii, stood out blocking mycelial growth from a distance. In the antifungal assay, D. anacardii PL01 (31.7%) and D. schini PL40 (18.2%) acetate metabolite stood out. In summary, our results indicate a few Diaporthe endophytes able to antagonize a S. sclerotiorum pathogen under in vitro conditions

Bioprospecting endophytic Diaporthe species associated with Pachystachys lutea (Acanthaceae) with antagonistic effect against Sclerotinia sclerotiorum

Endophytic microorganisms live inside the plant tissues symptomless. These microorganisma may present antagonistic activity against phytopathogens or produce metabolites with antifungal activity. We aimed to evaluate in vitro antagonism and competitive interactions between endophytic fungi of Diaporthe species and Sclerotinia sclerotiorum.  We also carried out in vitro screening of antifungal activity of metabolic extracts of the two endophytes against the pathogen. The antagonism was performed by the paired-culture and two promising antagonists strains were selected for metabolic extraction from the fermented culture. Metabolic extracts were obtainment using two different organic solvents (Ethyl Acetate and Hexane) and their antifungal activity was carried out using the agar diffusion test. The in vitro antagonistic index ranged from 22.1 to 59.5%, with Diaporthe sp. PL03 (59.1%), D. schini PL40 (59.5%), D. infecunda PL63 (41.8%), D. anacardii PL64 (56.8%), with inhibition by mycelial contact. The endophytes PL01 (28.6%) and PL43 (28.5%), both D. anacardii, stood out blocking mycelial growth from a distance. In the antifungal assay, D. anacardii PL01 (31.7%) and D. schini PL40 (18.2%) acetate metabolite stood out. In summary, our results indicate a few Diaporthe endophytes able to antagonize a S. sclerotiorum pathogen under in vitro conditions

Biotechnological potential of Pectobacterium sp. endophyte on the growth of soy and bean plants

Fertilizers and chemical pesticides supply plants´ nutritional requirements and protect them against pathogens. However, they may cause harm to the environment. Pectobacterium sp. has been reported as an endophyte with the capacity of a plant-growth promoter, especially in the control of phytopathogens. The current paper evaluates the capacity of the endophytic bacterium Pectobacterium sp. MG-60 isolated from Mikania glomerata Spreng. (Asteraceae) to antagonize phytopathogens in vitro, produce IAA, and fix nitrogen (nifH). Growth promotion assessments of bean and soybean plants under greenhouse conditions were also performed. The rate of antagonism against Sclerotinia sclerotiorum was 52.5%. The endophyte Pectobacterium sp. MG-60 produced 3.54 µg mL-1 of IAA when 5 mM L-tryptophan in the culture medium was used. Under greenhouse conditions, significant results for Pectobacterium sp. MG-60 in the growth of soybean and common bean plants were observed, especially in the height of common bean (19%) and soybean (20%), fresh weight of shoot (18.5%) and fresh weight of roots (46.8 %) of soybean plants. This is the first report on Pectobacterium isolated as an endophyte from M. glomerata with plant growth-promoting agent abilities with biotechnological potential for the agricultural field

Biotechnological potential of Pectobacterium sp. endophyte on the growth of soy and bean plants

Fertilizers and chemical pesticides supply plants’ nutritional requirements and protect them against pathogens. However, they may cause harm to the environment. Pectobacterium sp. has been reported as an endophyte with the capacity of a plant-growth promoter, especially in the control of phytopathogens. The current paper evaluates the capacity of the endophytic bacterium Pectobacterium sp. MG-60 isolated from Mikania glomerata Spreng. (Asteraceae) to antagonize phytopathogens in vitro, produce IAA, and fix nitrogen (nifH). Growth promotion assessments of bean and soybean plants under greenhouse conditions were also performed. The rate of antagonism against Sclerotinia sclerotiorum was 52.5%. The endophyte Pectobacterium sp. MG-60 produced 3.54 µg mL-1 of IAA when 5 mM L-tryptophan in the culture medium was used. Under greenhouse conditions, significant results for Pectobacterium sp. MG-60 in the growth of soybean and common bean plants were observed, especially in the height of common bean (19%) and soybean (20%), fresh weight of shoot (18.5%) and fresh weight of roots (46.8 %) of soybean plants. This is the first report on Pectobacterium isolated as an endophyte from M. glomerata with plant growth-promoting agent abilities with biotechnological potential for the agricultural field.</p