Biomass and Leaf Acclimations to Ultraviolet Solar Radiation in Juvenile Plants of Coffea arabica and C. canephora.

Despite the negative impacts of increased ultraviolet radiation intensity on plants, these organisms continue to grow and produce under the increased environmental UV levels. We hypothesized that ambient UV intensity can generate acclimations in plant growth, leaf morphology, and photochemical functioning in modern genotypes of Coffea arabica and C. canephora. Coffee plants were cultivated for ca. six months in a mini greenhouse under either near ambient (UVam) or reduced (UVre) ultraviolet regimes. At the plant scale, C. canephora was substantially more impacted by UVam when compared to C. arabica, investing more carbon in all juvenile plant components than under UVre. When subjected to UVam, both species showed anatomic adjustments at the leaf scale, such as increases in stomatal density in C. canephora, at the abaxial and adaxial cuticles in both species, and abaxial epidermal thickening in C. arabica, although without apparent impact on the thickness of palisade and spongy parenchyma. Surprisingly, C. arabica showed more efficient energy dissipation mechanism under UVam than C. canephora. UVam promoted elevated protective carotenoid content and a greater use of energy through photochemistry in both species, as reflected in the photochemical quenching increases. This was associated with an altered chlorophyll a/b ratio (significantly only in C. arabica) that likely promoted a greater capability to light energy capture. Therefore, UV levels promoted different modifications between the two Coffea sp. regarding plant biomass production and leaf morphology, including a few photochemical differences between species, suggesting that modifications at plant and leaf scale acted as an acclimation response to actual UV intensity.

Phenolic compounds from the rhizome of Renealmia nicolaioides Loes.: a new diarylheptanoid.

This study aims to identify phenolic compounds in dichloromethane and methanolic extracts of the rhizome of Renealmia nicolaioides collected in the North Region of Brazil. Two known diarylheptanoids, 1,7-bis(4-hydroxyphenyl)-(1E)-1-hepten-3-one (1), and 5R-1,7-bis(4-hydroxyphenyl)-1E-hepten-5-ol (2), and a new one (1R,2S,5S)-2-hydroxy-1,7(p-hydroxyphenyl)-centrolobine (3), as well as one flavonoid, 3-metoxi-quercetin (4) were isolated by chromatographic procedure and identified by spectroscopic techniques (1H and13C NMR, HRMS and CD). The acetyl derivative of 2 was used to confirm its structure. All four compounds are reported for the first time for this genus, and this is the first occurrence of compound 1 as a natural metabolite. The results reported here are unprecedented for the genus Renealmia.

Culture of mouse peritoneal macrophages with mouse serum induces lipid bodies that associate with the parasitophorous vacuole and decrease their microbicidal capacity against Toxoplasma gondii.

Lipid bodies [lipid droplets (LBs)] are lipid-rich organelles involved in lipid metabolism, signalling and inflammation. Recent findings suggest a role for LBs in host response to infection; however, the potential functions of this organelle in Toxoplasma gondii infection and how it alters macrophage microbicidal capacity during infection are not well understood. Here, we investigated the role of host LBs in T. gondii infection in mouse peritoneal macrophages in vitro. Macrophages cultured with mouse serum (MS) had higher numbers of LBs than those cultured in foetal bovine serum and can function as a model to study the role of LBs during intracellular pathogen infection. LBs were found in association with the parasitophorous vacuole, suggesting that T. gondii may benefit from this lipid source. Moreover, increased numbers of macrophage LBs correlated with high prostaglandin E2 (PGE2) production and decreased nitric oxide (NO) synthesis. Accordingly, LB-enriched macrophages cultured with MS were less efficient at controlling T. gondii growth. Treatment of macrophages cultured with MS with indomethacin, an inhibitor of PGE2 production, increased the microbicidal capacity against T. gondii. Collectively, these results suggest that culture with MS caused a decrease in microbicidal activity of macrophages against T. gondii by increasing PGE2 while lowering NO production.

Culture of mouse peritoneal macrophages with mouse serum induces lipid bodies that associate with the parasitophorous vacuole and decrease their microbicidal capacity against Toxoplasma gondii

Lipid bodies [lipid droplets (LBs)] are lipid-rich organelles involved in lipid metabolism, signalling and inflammation. Recent findings suggest a role for LBs in host response to infection; however, the potential functions of this organelle in Toxoplasma gondii infection and how it alters macrophage microbicidal capacity during infection are not well understood. Here, we investigated the role of host LBs in T. gondii infection in mouse peritoneal macrophages in vitro. Macrophages cultured with mouse serum (MS) had higher numbers of LBs than those cultured in foetal bovine serum and can function as a model to study the role of LBs during intracellular pathogen infection. LBs were found in association with the parasitophorous vacuole, suggesting that T. gondii may benefit from this lipid source. Moreover, increased numbers of macrophage LBs correlated with high prostaglandin E2 (PGE2) production and decreased nitric oxide (NO) synthesis. Accordingly, LB-enriched macrophages cultured with MS were less efficient at controlling T. gondii growth. Treatment of macrophages cultured with MS with indomethacin, an inhibitor of PGE2 production, increased the microbicidal capacity against T. gondii. Collectively, these results suggest that culture with MS caused a decrease in microbicidal activity of macrophages against T. gondii by increasing PGE2 while lowering NO production.

Histological analysis of pollen-pistil interactions in sour passion fruit plants (Passiflora edulis Sims)

The success of sexual plant reproduction is directly influenced by specific interactions between the pollen and pistil. Light, fluorescence and scanning electron microscopy techniques were used to evaluate the steps of pollination in sour passion fruit plants (Passiflora edulis Sims). In the compatible interaction, pollen tubes grow through stigma projections towards the ovary. The pollen grain surface was found to be spheroidal and to consist of heteroreticulate exine with six colpi. Furthermore, analysis in vivo of pollen-pistil interactions indicated that stigmas of flowers 24 hours before anthesis are unable to discriminate compatible (genetically unrelated) and incompatible (genetically related) pollen grains. Taken together, these results provide insight into the cellular mechanisms underlying pollination in passion fruit plants.

Histological analysis of pollen-pistil interactions in sour passion fruit plants (Passiflora edulis Sims)

The success of sexual plant reproduction is directly influenced by specific interactions between the pollen and pistil. Light, fluorescence and scanning electron microscopy techniques were used to evaluate the steps of pollination in sour passion fruit plants (Passiflora edulis Sims). In the compatible interaction, pollen tubes grow through stigma projections towards the ovary. The pollen grain surface was found to be spheroidal and to consist of heteroreticulate exine with six colpi. Furthermore, analysis in vivo of pollen-pistil interactions indicated that stigmas of flowers 24 hours before anthesis are unable to discriminate compatible (genetically unrelated) and incompatible (genetically related) pollen grains. Taken together, these results provide insight into the cellular mechanisms underlying pollination in passion fruit plants.(AU)

Structural and ecophysiological alterations of the water hyacinth [Eichhornia crassipes (Mart.) Solms] due to anthropogenic stress in Brazilian rivers

In this work, the structural and ecophysiological alterations (chlorophyll a fluorescence and photosynthetic pigments), and quantification of Cr, Pb and Zn in the leaf limb, petiole and younger and older roots of water hyacinth from the lower, medium and upper Paraíba do Sul river (PSR) and Imbé river were evaluated. The plants from the medium and upper PSR (more industrialized and populated regions) exhibited lower turgid cell in the root cortex, less root hairs and leaf epidermis, chloroplasts with plastoglobules and increased stroma volume. Higher concentrations of metals were observed in the younger and older roots from the medium PSR plants. The results suggested that the plants from more anthropized regions were able to maintain the maximum quantum yield (Fv/Fm) which was a result from the metabolic fitting, increasing the non-photochemical quenching, reducing total chlorophyll/carotenoids and leading to the structural modifications.

Purification and characterization of beta-1, 3-glucanase from the secretion of Simira glaziovii colleters (Rubiaceae)

In this study, beta-1,3-glucanase was isolated from Simira glaziovii secretion. The purification process was achieved by a combination of chromatographic methods and was analyzed by SDS-PAGE. The purified enzyme presented an estimated molecular mass of 35 kDa. The optimum pH of enzyme was 5.2

Uma beta-1,3-glucanase foi purificada a partir da secreção de Simira glaziovii, através de vários processos cromatográficos, tendo a análise do perfil protéico acompanhado de SDS-PAGE. A enzima purificada apresentou uma massa molecular estimada de 35 kDa. O pH ótimo obtido para a enzima foi de 5,2.

The laticifer system of Chamaesyce thymifolia: a closed host environment for plant trypanosomatids

Specimens of Chamaesyce thymifolia (Euphorbiaceae) infected and uninfected by Phytomonas sp., a parasite of the Trypanosomatidae family, were anatomically and ultrastructurally analyzed with special emphasis on the laticifer system. C. thymifolia presents branched non-articulated laticifers and was heavily infected by Phytomonas sp. in all collection sites. Infection was often observed in the initial stages inside the vacuole, when the latex particles could be seen. In intermediary stages of laticifer differentiation, Phytomonas sp. were found free in the cytoplasm, inside small vacuoles or in the central vacuole. In differentiated laticifers that had only the plasma membrane, Phytomonas sp. were free in the latex and close to the cell membrane. Infected and uninfected plants showed identical anatomy and ultrastructure and the starch grain numbers in the latex were not reduced in the presence of this flagellate. Biochemical analysis of the latex of infected and uninfected plants presented similar levels of protein, carbohydrate and beta-1,3-glucanase, suggesting that this species is not pathogenic for the host. Besides, all infected plants complete its life cycle. Plants infected with Phytomonas presented occasionally virus like particles and bacteria inside the laticifer tubes.

The laticifer system of Chamaesyce thymifolia: a closed host environment for plant trypanosomatids

Specimens of Chamaesyce thymifolia (Euphorbiaceae) infected and uninfected by Phytomonas sp., a parasite of the Trypanosomatidae family, were anatomically and ultrastructurally analyzed with special emphasis on the laticifer system. C. thymifolia presents branched non-articulated laticifers and was heavily infected by Phytomonas sp. in all collection sites. Infection was often observed in the initial stages inside the vacuole, when the latex particles could be seen. In intermediary stages of laticifer differentiation, Phytomonas sp. were found free in the cytoplasm, inside small vacuoles or in the central vacuole. In differentiated laticifers that had only the plasma membrane, Phytomonas sp. were free in the latex and close to the cell membrane. Infected and uninfected plants showed identical anatomy and ultrastructure and the starch grain numbers in the latex were not reduced in the presence of this flagellate. Biochemical analysis of the latex of infected and uninfected plants presented similar levels of protein, carbohydrate and beta-1,3-glucanase, suggesting that this species is not pathogenic for the host. Besides, all infected plants complete its life cycle. Plants infected with Phytomonas presented occasionally virus like particles and bacteria inside the laticifer tubes.(AU)