ABSTRACT
This study evaluated the effects of potassium and sodium carbonate and bicarbonate, Bacillus subtilis (Cohn, 1872) QST-713, Bacillus pumilus (Meyer & Gottheil, 1901) QST-2808, and crude and roasted coffee oils on the inhibition of mycelial growth and conidial germination in Botrytis cinerea Pers.: Fr and the colonization of begonia (Begonia elatior Hort. ex Steud) leaf discs by B. cinerea inoculated before, simultaneously and after with these alternative products. The assays were carried out using the Baladin begonia cultivar. The inhibition of B. cinerea mycelial growth and conidial germination was proportional to increases in the concentration of all the products. The inhibition of conidial germination was directly proportional to the concentrations of B. pumilus QST-2808 and B. subtilis QST-713. Coffee oils were less efficient in inhibiting germination than the other products. The crude and roasted coffee oils, potassium and sodium carbonates and bicarbonates, and B. pumilus and B. subtilis sprayed 24 h before, simultaneously, or 24 h after pathogen inoculation inhibited the colonization of begonia leaf discs by B. cinerea. The positive results for the suppression of B. cinerea by the alternative products tested herein merit scrutiny. There is a pressing need to evaluate these products in the management of gray mold, as the severity of this disease is usually high under favorable conditions in greenhouses.
Subject(s)
Salts/analysis , Bacillus subtilis , Botrytis/pathogenicity , Begoniaceae/drug effects , Bacillus pumilus , Growth Inhibitors/analysisABSTRACT
Plant biochemistry studies have increased in recent years due to their potential to improve human health. Argylia radiata is an extremophile plant with an interesting polyphenolic profile. However, its biomass is scarce and occasionally available. Argylia in vitro biomass was obtained from tissue culture and compared with in vivo roots regarding its polyphenolic and flavonoid content. Different solvents were used to prepare extracts from the in vitro tissue of callus and aerial plant organs and in vivo roots. UPLC-MS/MS was used to assess the chemical composition of each extract. ORAC-FL and scavenging of free radicals (DPPH and OH) methods were used to determine the antioxidant capacity of extracts. Furthermore, the biological activity of the extracts was established using the cellular antioxidant activity method. The vitroplants were a good source of polyphenols (25-68 mg GAE/100 g tissue FW), and methanol was the most efficient solvent. Eight polyphenolic compounds were identified, and their antioxidant properties were investigated by different chemical methods with EPR demonstrating its specific scavenging activity against free radicals. All extracts showed cellular dose-dependent antioxidant activity. The methanolic extract of vitroplants showed the highest cellular antioxidant activity (44.6% and 51%) at 1 and 10 µg/mL of extract, respectively. Vitroplants of A. radiata are proposed as a biotechnological product as a source of antioxidant compounds with multiple applications.
Subject(s)
Antioxidants/pharmacology , Begoniaceae/chemistry , Free Radical Scavengers/pharmacology , Plant Roots/chemistry , Polyphenols/analysis , Polyphenols/pharmacology , Solvents/chemistryABSTRACT
Fungi in the genus Trichoderma are notorious producers of secondary metabolites with diverse applications, such as antibacterial, antifungal, and plant growth-promoting properties. Peptaibols are linear peptides produced by such fungi, with more than 440 compounds described to date, including tricholongins, longibrachins, trichobrachins, and trichovirins. Peptaibols are synthesized by non-ribosomal peptide synthetases and they have several biological activities. Our research group isolated four peptaibols (6DP2, 6DP3, 6DP4, and 6DP5) with antifungal activity against the plant pathogen Colletotrichum gloeosporioides and the proteasome (a cancer chemotherapy target) from Trichoderma sp. P8BDA1F1, an endophytic fungus from Begonia venosa. The ethyl acetate extract of this endophyte showed activity of 6.01% and 75% against C. gloeosporioides and the proteasome, respectively. The isolated compounds were identified by MS/MS and compared to literature data, suggesting the presence of trilongins BI, BII, BIII, and BIV, which are peptaibols containing 20 amino acid residues. The minimum inhibitory concentration against C. gloeosporioides was 40 µM for trilongin BI, 320 µM for trilongin BII, 160 µM for trilongin BIII, and 310 µM for trilongin BIV. BI-BIV trilongins inhibited proteasome ChTL activity, with IC50 values of 6.5 ± 2.7; 4.7 ± 1.8; 6.3 ± 2.2; and 2.7 ± 0.5 µM, respectively. The compounds were tested ex vivo against the intracellular amastigotes of Leishmania (L.) infantum but showed no selectivity. It is the first report of trilongins BI-BIV with antifungal activity against C. gloeosporioides and the proteasome target.
Subject(s)
Antifungal Agents/pharmacology , Antineoplastic Agents/pharmacology , Begoniaceae/microbiology , Peptaibols/pharmacology , Trichoderma/chemistry , Antifungal Agents/chemistry , Antifungal Agents/isolation & purification , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification , Colletotrichum/drug effects , Endophytes , Inhibitory Concentration 50 , Microbial Sensitivity Tests , Peptaibols/chemistry , Peptaibols/isolation & purification , Phylogeny , Proteasome Inhibitors/pharmacology , Trichoderma/classification , Trichoderma/genetics , Trichoderma/isolation & purificationABSTRACT
El presente estudio corresponde a la primera entrega donde se realizó el análisis farmacobotánico, etnofarmacológico y micrográfico de drogas vegetales utilizadas en forma empírica para las afecciones con mayor tasa de mortalidad en la provincia de Misiones. En esta primera instancia (Parte I), se exponen seis (6) especies utilizadas para las afecciones cardiovasculares y respiratorias. Las mismas fueron relevadas en los diferentes puntos de comercialización de la Ciudad de Posadas. Se conservaron especímenes de resguardo en el Herbario del Departamento de Farmacia de la Facultad de Ciencias Exactas, Químicas y Naturales de la Universidad Nacional de Misiones y mediante fotografías, se identificaron por medio de procedimientos taxonómicos clásicos, y se analizó la endo- y exomorfología empleando técnicas de rutina para este tipo de trabajo, con la documentación fotográfica. Los objetivos fueron relevar y documentar las especies vegetales utilizadas para las afecciones cardiovasculares y respiratorias, sus usos etnofarmacológicos, las partes utilizadas y formas de administración, además de contribuir a incrementar el conocimiento de la morfo-anatomía y micrografía aplicada de dichas drogas vegetales. Los resultados obtenidos en esta instancia se corresponden con el relevamiento de Syagrus romanzoffiana, Cuphea calophylla subsp. mesostemon, Hypericum connatum, Begonia cucullata, Cecropia pachystachya y Luehea divaricata, especies comercializadas y utilizadas como agentes terapéuticos en el tratamiento de las afecciones cardiovasculares y respiratorias.
The present study corresponds to the first delivery where the pharmacobotanical, ethnopharmacological and micrographic analysis of vegetable drugs used empirically for the conditions with the highest mortality rate in the province of Misiones was carried out. In this first instance (Part I), six (6) species used for cardiovascular and respiratory diseases are exposed. They were surveyed at different points of sale in the City of Posadas. Specimens were kept in the Herbarium of the Department of Pharmacy of the Faculty of Exact, Chemical and Natural Sciences of the National University of Misiones and photographed, were identified by means of classical taxonomic procedures, and the endo- and exomorphology were analyzed using routine techniques for this type of work, with photographic documentation. The objectives were to survey and document the plant species used for cardiovascular and respiratory diseases, their ethnopharmacological uses, parts used and forms of administration, in addition to contributing to increase the knowledge of the morpho-anatomy and applied micrograph of said plant drugs. The results obtained in this instance correspond to Syagrus romanzoffiana, Cuphea calophylla subsp. mesostemon, Hypericum connatum, Begonia cucullata, Cecropia pachystachya and Luehea divaricata survey, commercialized species and used as therapeutic agents in the treatment of cardiovascular and respiratory affections.
Subject(s)
Begoniaceae , Argentina , Mortality , Medicine, TraditionalABSTRACT
Tropical plants represent hotspots of endophytic fungal species diversity. Based on culture-dependent methods, we evaluated the endophytic fungal communities in leaves of three plant species found in the Brazilian Atlantic Rainforest: Begonia fischeri, Begonia olsoniae, and Begonia venosa. These species are found in two distant sites: a continental region and an insular area. A total of 426 fungal endophytes in 19 genera were isolated in pure culture including Colletotrichum (51.6% of isolates) and Diaporthe (22.5%) as the most abundant, followed by Phyllosticta (3.5%), Neopestalotiopsis (1.8%), Stagonospora (1.8%), and Nigrospora (1.6%) among the genera found in minor abundance. The diversity and composition of fungal taxa differed across plant hosts. Richness and diversity of fungi were higher in B. fischeri in comparison to B. olsoniae and B. venosa. Discriminatory analysis revealed that fungal communities are structured according to hosts, which means that each plant species had its distinct endophytic communities, but dominated by common fungal taxa. This is the first study to report fungal endophytes in begonia leaves and characterize their communities.
Subject(s)
Begoniaceae/microbiology , Endophytes/isolation & purification , Fungi/isolation & purification , Biodiversity , Brazil , Endophytes/classification , Endophytes/genetics , Fungi/classification , Fungi/genetics , Phylogeny , RainforestABSTRACT
A major goal of evolutionary biology is to determine the mechanisms generating biodiversity. In Begonia, one of the largest plant genera (1900+ species), it has been postulated that the high number of endemic species is a by-product of low gene flow among populations, which predisposes the group to speciation. However, this model of divergence requires that reproductive barriers accumulate rapidly among diverging species that overlap in their geographic ranges, otherwise speciation will be opposed by homogenizing gene flow in zones of secondary contact. Here, we test the outcomes of secondary contact in Begonia by genotyping multiple sympatric sites with 12 nuclear and seven plastid loci. We show that three sites of secondary contact between B. heracleifolia and B. nelumbiifolia are highly structured, mostly containing parental genotypes, with few F1 hybrids. A sympatric site between B. heracleifolia and B. sericoneura contains a higher proportion of F1s, but little evidence of introgression. The lack of later-generation hybrids contrasts with that documented in many other plant taxa, where introgression is extensive. Our results, in conjunction with previous genetic work, show that Begonia demonstrate properties making them exceptionally prone to speciation, at multiple stages along the divergence continuum. Not only are populations weakly connected by gene flow, promoting allopatric speciation, but species often show strong reproductive barriers in secondary contact. Whether similar mechanisms contribute to diversification in other large genera remains to be tested.
Subject(s)
Begoniaceae/classification , Genetic Speciation , Genetic Variation , Genetics, Population , Cell Nucleus/genetics , DNA, Chloroplast/genetics , DNA, Plant/genetics , Evolution, Molecular , Gene Flow , Genotype , Haplotypes , Hybridization, Genetic , Mexico , Sequence Analysis, DNA , SympatryABSTRACT
Begonia is one of the ten largest plant genera, with over 1500 species. This high species richness may in part be explained by weak species cohesion, which has allowed speciation by divergence in allopatry. In this study, we investigate species cohesion in the widespread Central American Begonia heracleifolia and Begonia nelumbiifolia, by genotyping populations at microsatellite loci. We then test for post-zygotic reproductive barriers using experimental crosses, and assess whether sterility barriers are related to intraspecific changes in genome size, indicating major genome restructuring between isolated populations. Strong population substructure was found for B. heracleifolia (FST=0.364, F'ST=0.506) and B. nelumbiifolia (FST=0.277, F'ST=0.439), and Bayesian admixture analysis supports the division of most populations into discrete genetic clusters. Moderate levels of inferred selfing (B. heracleifolia s=0.40, B. nelumbiifolia s=0.62) and dispersal limitation are likely to have contributed to significant genetic differentiation (B. heracleifolia Jost's D=0.274; B. nelumbiifolia D=0.294). Interpopulation crosses involving a divergent B. heracleifolia population with a genome size â¼10% larger than the species mean had a â¼20% reduction in pollen viability compared with other outcrosses, supporting reproductive isolation being polymorphic within the species. The population genetic data suggest that Begonia populations are only weakly connected by gene flow, allowing reproductive barriers to accumulate between the most isolated populations. This supports allopatric divergence in situ being the precursor of speciation in Begonia, and may also be a common speciation mechanism in other tropical herbaceous plant groups.
Subject(s)
Begoniaceae/genetics , Genetic Variation , Central America , Genetic Speciation , Genotype , Microsatellite Repeats/geneticsABSTRACT
Sex allocation theory predicts that reproducing individuals will increase their fitness by facultatively adjusting their relative investment towards the rarer sex in response to population shifts in operational sex ratio (OSR). The evolution of facultative manipulation of sex ratio depends on the ability of the parents to track the conditions favouring skewed sex allocation and on the mechanism controlling sex allocation. In animals, which have well-developed sensorial mechanisms, facultative adjustment of sex ratios has been demonstrated on many occasions. In this paper, we show that plants have mechanisms that allow them to evaluate the population OSR. We simulated three different conditions of population OSR by manipulating the amount of pollen received by the female flowers of a monoecious herb, and examined the effect of this treatment on the allocation to male vs. female flowers. A shortage of pollen on the stigmas resulted in a more male-skewed sex allocation, whereas plants that experienced a relatively pollen rich environment tended to produce a more female-skewed sex allocation pattern. Our results for Begonia gracilis demonstrate that the individuals of this species are able to respond to the levels of pollination intensity experienced by their female flowers and adjust their patterns of sex allocation in accordance to the expectations of sex allocation theory.
Subject(s)
Begoniaceae/genetics , Begoniaceae/physiology , Biological Evolution , Models, Theoretical , Sex Ratio , Pollen , Population DynamicsABSTRACT
Argylia radiata (L.) D. Don (Bignoniaceae) represents an important source of secondary metabolites, largely unexplored. The paper presents the isolation from the plant root of two new monoterpene alkaloids, 10-acetoxy-actinidine and 4-nor-7,8-dehydro-10-hydroxy-skytanthine, whose structures were elucidated by Mass spectrometry and 1H-NMR data.