Seed biometry: another functional trait in caatinga

Seed biometrics is an excellent tool for understanding environmental filters, species potential and dispersal, successional stages of communities and the dynamics used by seeds to germinate, establish and develop, thus constituting a functional trait of the species. We aim to understand the relationship between aspects of seed biometrics and other phenological traits, in order to infer contributions about functional strategies in Caatinga. Between September 2017 and January 2019, 10 individuals of Cenostigma pyramidale(Tul.) LP Queiroz, Commiphora lepthophloeos(Mart.) JB Gillett, Jatropha mollissima(Pohl.) Baill., Monteverdia rigida(Mart.) Biral. Pseudobombax marginatum(A.ST.-Hil) A. Robyns, Zizyphus joazeiroMart. were monitored for the selection of three seed collection matrices. From each matrix 100 seeds were collected, which after screening resulted in 35 intact seeds that were used to measure length, width, thickness and volume. Caatinga seeds are generally small, as a result of the environmental stresses of the Brazilian semiarid. The analyzed variables separated three groups in the PCA. We noticed that these groups evidenced the successional stages in the Caatinga. One group included M. rigidaand P. marginatum,which are late secondary. C. pyramidaleand C. lepthophloeosformed another group coincident with intermediate successional stages. J. mollissimaand Z. joazeiroformed a group of pioneer species in anthropized environments. Another finding was that the area was in secondary succession. Thepioneer species presented the largest seeds and this characteristic is associated with the need for nutrient reserve that allows the embryo to germinate and last for a longer period without the need for exogenous nutrients, an essential condition for the Caatinga. With the advancement of ecological succession and the establishment of a more consolidated plant community, competition for resources, the frequent dispersion vector type and the nature of the environmental stresses present, the seeds may be smaller.

Potencial antimicrobiano de seis plantas do semiárido paraibano contra bactérias relacionadas à infecção endodôntica / Antimicrobial potential of six plants from the semiarid zone of Paraíba State (Brazil) against bacteria related to endodontic infection

Com o aumento dos microrganismos resistentes às substâncias antimicrobianas já conhecidas, vários extratos de plantas medicinais foram testados com a finalidade de procurar novos compostos com atividade antimicrobiana reconhecida. Assim este estudo teve como objetivo avaliar a atividade antimicrobiana de diferentes extratos vegetais em bactérias relacionadas à infecção endodôntica. Foram testados os extratos hidroalcóolicos das espécies Syderoxylum obtusifolium Roem e Schult (quixabeira), Bauhínia forficata Linn (mororó), Anadenanthera colubrina Brenan (angico), Spondias tuberosa Arruda (umbuzeiro), Tabebuia pentaphylla Vell. (ipê rosa) e Guapira graciliflora Mart. (joão-mole), contra o Enterococcus faecalis, Staphylococcus aureus e Escherichia coli. Foram realizados os ensaios antimicrobianos pela técnica do disco difusão em ágar e pelo método de microdiluição em caldo. Todos os extratos analisados apresentaram atividade antimicrobiana contra pelo menos uma espécie bacteriana. Os melhores resultados foram encontrados com T. pentaphylla Vell e G. graciliflora Mart, apresentando atividade contra todas as cepas testadas, destacando-se a atividade de T. pentaphylla Vell frente a S.aureus na concentração de 0,78μl/μl e da casca de G. graciliflora Mart frente a E.faecalisna concentração de 6,25μl/μl. Os resultados sinalizam o potencial antimicrobiano dessas plantas, podendo ser promissoras para estudos de desenvolvimento de novos produtos de uso endodôntico.

In the face of an increasing range of microorganisms known to be resistant to antimicrobial substances, various herbal extracts have been screened in order to find new compounds with recognized antimicrobial activity. In particular, this study was carried out to assess the antimicrobial activity of such extracts on bacteria related to endodontic infection. Hydroalcoholic extracts of the species Syderoxylum obtusifolium Roem and Schult (quixabeira), Bauhinia forficata Linn (mororó) Anadenanthera colubrina Brenan (angico), Spondias tuberosa Arruda (umbuzeiro), Tabebuia pentaphylla Vell. (ipê rosa) and Guapira graciliflora Mart. (joão-mole), were tested against Enterococcus faecalis, Staphylococcus aureus and Escherichia coli. The antimicrobial assays were performed by the disk agar diffusion and broth microdilution methods. All extracts analyzed showed antimicrobial activity against at least one bacterial species. The best results were obtained with T. pentaphylla and G. graciliflora, which showed activity against all tested strains; specifically, that of T. pentaphylla against S. aureus, at a concentration of 0.78μL/μL, and of G. graciliflora bark against E. faecalis, at a concentration of 6.25μL/μL, should be highlighted. The results indicate that extracts of these plants may be promising for the study and development of new antimicrobials for endodontic use.