[Estimation of prevalence of chronic Chagas disease in Brazilian municipalitiesEstimación de la prevalencia de la enfermedad de Chagas crónica en los municipios brasileños].

Objective: The objective of this study is to estimate the prevalence of chronic Chagas disease (CCD) in Brazil: in the general population, in women, and in women of childbearing age.

Methods: A meta-analysis of the literature was conducted to extract data on the prevalence of CCD in municipalities in Brazil in the 2010-2022 period: in the general population, in women, and in women of childbearing age. Municipal-level CCD indicators available in health information systems were selected.

Biosynthesis of silver nanoparticles using actinomycetes, phytotoxicity on rice seeds, and potential application in the biocontrol of phytopathogens.

To find effective silver nanoparticles (AgNPs) for control of phytopathogens, in this study, two strains of actinomycetes isolated from the soil of the Brazilian biome Caatinga (Caat5-35) and from mangrove sediment (Canv1-58) were utilized. The strains were identified by using the 16S rRNA gene sequencing as Streptomyces sp., related to Streptomyces mimosus species.

The regulation of P700 is an important photoprotective mechanism to NaCl-salinity in Jatropha curcas.

Salinity commonly affects photosynthesis and crop production worldwide. Salt stress disrupts the fine balance between photosynthetic electron transport and the Calvin cycle reactions, leading to over-reduction and excess energy within the thylakoids. The excess energy triggers reactive oxygen species (ROS) overproduction that causes photoinhibition in both photosystems (PS) I and II.

Proteomic and physiological approaches reveal new insights for uncover the role of rice thylakoidal APX in response to drought stress.

Chloroplast APX isoforms display controversial roles as HO scavengers and signaling players in response to abiotic stress and conclusive results are lacking. We tested the hypothesis that thylakoidal APX displays an important role for drought tolerance, especially by regulating abundance of essential protein species. For this, OsApx8 RNAi-silenced rice (apx8) and non-transformed plants (NT) were exposed to mild water deficit.

Silenced rice in both cytosolic ascorbate peroxidases displays pre-acclimation to cope with oxidative stress induced by 3-aminotriazole-inhibited catalase.

The maintenance of H2O2 homeostasis and signaling mechanisms in plant subcellular compartments is greatly dependent on cytosolic ascorbate peroxidases (APX1 and APX2) and peroxisomal catalase (CAT) activities. APX1/2 knockdown plants were utilized in this study to clarify the role of increased cytosolic H2O2 levels as a signal to trigger the antioxidant defense system against oxidative stress generated in peroxisomes after 3-aminotriazole-inhibited catalase (CAT). Before supplying 3-AT, silenced APX1/2 plants showed marked changes in their oxidative and antioxidant profiles in comparison to NT plants.

Exogenous sucrose supply changes sugar metabolism and reduces photosynthesis of sugarcane through the down-regulation of Rubisco abundance and activity.

Photosynthetic modulation by sugars has been known for many years, but the biochemical and molecular comprehension of this process is lacking. We studied how the exogenous sucrose supplied to leaves could affect sugar metabolism in leaf, sheath and stalk and inhibit photosynthesis in four-month old sugarcane plants. Exogenous sucrose 50mM sprayed on attached leaves strongly impaired the net CO2 assimilation (PN) and decreased the instantaneous carboxylation efficiency (PN/Ci), suggesting that the impairment in photosynthesis was caused by biochemical restrictions.

Dissipation of excess photosynthetic energy contributes to salinity tolerance: a comparative study of salt-tolerant Ricinus communis and salt-sensitive Jatropha curcas.

The relationships between salt tolerance and photosynthetic mechanisms of excess energy dissipation were assessed using two species that exhibit contrasting responses to salinity, Ricinus communis (tolerant) and Jatropha curcas (sensitive). The salt tolerance of R. communis was indicated by unchanged electrolyte leakage (cellular integrity) and dry weight in leaves, whereas these parameters were greatly affected in J.