Molecular and Chemical Analyses of Cyanobacterial Blooms in Tropical Lagoons from Southeast Brazil

The genetic diversity and the potential toxicity of bloom-forming cyanobacteria were studied in four lagoons located in the state of Sao Paulo (Campinas, Limeira and Piracicaba cities). Bloom samples were collected on the water surface and cyanobacterial communities were evaluated using DGGE fingerprinting and 16S rDNA clone library. The amplification of genes encoding secondary metabolites such as microcystin (mcy), anatoxin (ana), cylindrospermopsin (cyr), saxitoxin (sxt), cyanopeptolin (mcn) and aeruginosin (aer) was performed and their production analyzed by LC-MS. The comparison of DGGE banding pattern among the different water samples suggested that some operational taxonomic units (OTUs) in these locations were predominant over others. The 16S rDNA clone libraries sequences matched with nine different known cyanobacterial genera available in NCBI, identified as Anabaena, Brasilonema, Cylindrospermopsis, Limnococcus, Microcystis, Nostoc, Pseudanabaena, Synechococcus and Woronichinia. The lagoons ESALQ2, Taquaral and Limeira had more than 80% of the cyanobacterial community assigned to the genus Microcystis. Genes encoding aeruginosin, cyanopeptolin and microcystin synthetases and saxitoxin synthase were amplified, and LC-MS/MS confirmed the production of aeruginosin, cyanopeptolin and microcystin. Rapid and sensitive methods for the detection of these secondary metabolites, especially toxins, using chemical and molecular tools together, can be used for a faster diagnostic of toxic cyanobacterial blooms.

The effect of global warming on beef production in developing countries of the southern hemisphere

Developing countries from the southern hemisphere will be confronted by the same beef production challenges caused by global warming, because these countries are at the same geographical positions in southern latitudes. Global warming is expected to have a more extreme effect on the southern hemisphere than on other continents and will have a negative effect on the beef production environments in these countries. The negative effects will include high ambient temperatures, nutritional stress and altered patterns of animal diseases. Heat stress in beef cattle on veld/savannah is expected to increase as a result of changing weather patterns on a global and regional scale. This may negatively influence food production from beef cattle for the human food chain. Negative effects of increased temperatures and thus heat stress can include lower reproductive rates and weaning weights. The effect of heat stress can be partly addressed by nutritional strategies, such as replacing rapid fermentable carbohydrates with saturated fatty acids and the feeding of more by-pass protein and dietary electrolytes. Global warming will also alter the distribution pattern of animal diseases and the vectors of some of these diseases. This may even include the spread to South American countries. Likewise the nutritional value of natural pastures may be influenced. The effect of global warming on the quality of pastures will depend on whether the global warming is a result of increased carbon dioxide levels or not. An improved understanding of the adaptation of beef cattle to their production environments is important, but adaptation is complex and thus difficult to measure. Fortunately, several proxy-indicators for adaptation such as reproductive, production and health traits are available. The selection of animals and genotypes that are better adapted to the production system, including heat stress, is possible and should be persuade to ensure sustainable beef production in hotter climates.

Intraguild niche partitioning in granivorous birds from the late past

Niche partitioning is a widespread ecological strategy within trophic guilds,ensuring the coexistence of sympatric species by reducing interspecific competition.Stable isotope analysis of carbon and nitrogen and isotopic niche metrics(width and overlap)are used as a proxy to investigate niche partitioning among species of a guild.In our study,we investigated if niche partitioning was an ecological mechanism contributing to the coexistence of granivorous birds from the same geographic region along time,employing an isotopic approach.We sampled and isotopically analyzed(δ^(13)C andδ^(15)N values)wing feathers from 58 specimens of granivorous birds collected between 1900 and 1966 in southeastern Brazil.We grouped birds according to the main habitat type used by them(forest:Cyanoloxia brissonii,Leptotila and Leptotila verreauxi;and grassland:Columbina squammata and Sicalis flaveola).We used the Isotopic Richness(IRic)metric to measure the isotopic niche width and the Isotopic Similarity(ISim)and Isotopic Nestedness(INes)metrics to measure the niche overlap between groups and species.The results of low isotopic niche overlap suggest that common granivorous birds had a clear niche partitioning in southeastern Brazil in the late past,especially through foraging in distinct habitat types(forest and grassland;ISim=0.1,INes=0.2).Niche overlaps in almost all species-by-species comparisons were low(ISim≤0.3,INes≤0.4),except between C.brissonii and L.verreauxi(ISim=0.6,INes=1.0).These results suggest that these birds,belonging to the same trophic guild,coexisted through niche and resource partitioning.Despite being considered a plastic trophic guild,the isotopic niche partitioning among granivorous birds indicates that each of these species uses a set of specific resources and habitats.This raises an ecological concern about the homogenization of landscapes across the Neotropics,oversimplifying food resources and habitats to granivorous birds.

Multielement determination in orange juice by ICP-MS associated with data mining for the classification of organic samples

The aim of this study was to discriminate organic from conventional orange juice based on chemical elements and data mining applications.A comprehensive sampling of organic and conventional oranges was carried out in Borborema,state of Sao Paulo,Brazil.The fruits of the variety Valencia(Citrus sinensis(L.)Osbeck)budded on Rangpur lime(Citrus limonia Osbeck)were analyzed.Eleven chemical elements were determined in 57 orange samples grown in organic and conventional systems.In order to classify these samples,data mining techniques(Support Vector Machine(SVM)and Multilayer Perceptron(MLP))were combined with feature selection(F-score and chi-squared).SVM with chi-squared had a better performance compared with the other techniques because it reached 93.00% accuracy using only seven chemical components(Cu,Cs,Zn,Al,Mn,Rb and Sr),and correctly classified 96.73% of the samples grown in an organic system.

Temporal and spatial control of gene expression inhorticultural crops

Biotechnology provides plant breeders an additional tool to improve various traits desired by growers and consumers of horticultural crops.It also provides genetic solutions to major problems affecting horticultural crops and can be a means for rapid improvement of a cultivar.With the availability of a number of horticultural genome sequences,it has become relatively easier to utilize these resources to identify DNA sequences for both basic and applied research.Promoters play a key role in plant gene expression and the regulation of gene expression.In recent years,rapid progress has been made on the isolation and evaluation of plant-derived promoters and their use in horticultural crops,as more and more species become amenable to genetic transformation.Our understanding of the tools and techniques of horticultural plant biotechnology has now evolved from a discovery phase to an implementation phase.The availability of a large number of promoters derived from horticultural plants opens up the field for utilization of native sequences and improving crops using precision breeding.In this review,we look at the temporal and spatial control of gene expression in horticultural crops and the usage of a variety of promoters either isolated from horticultural crops or used in horticultural crop improvement.

巴西亚马孙阿马帕州境内两湖流域人发和环境样品中的汞

本文测定了巴西亚马孙阿马帕州两个相似湖泊中的沉积物、食鱼鱼以及湖区人发中的总汞量。这两个湖分别为:受采金矿区排放汞影响的Duas Boeas湖(DBL)和其北部15km处原始的Praeudba湖(PL)。在DBL沉积物中,纵剖面汞的含量范围为汞污染的发展进程提供了清晰的证据,并且发现DBL区鱼体和人发中汞的含量远远高于PL区。沉积物中的^(203)Hg甲基化速率及鱼体中甲基汞的比率,都显示出汞在两湖中具有较高的生物有效性。当地成年人每天平均食鱼量约为200g,而在DBL湖,95%的鱼样(样品数N=40)超过15ng Hg/g这一安全限。Hg在人发中平均含量为28μg/g(N=15),已在一个可引发神经中毒效应的水平上。然而,在未受污染的PL湖,汞含量也较高,在这里67%～100%(N=34)鱼类的汞含量超过安全限,87%的人发样品(N=15)高于10ng Ha/g。建议这两个区域的儿童和孕妇应吃非食鱼性的鱼类和/或小鱼类,对阿马帕沿海平原的其他区域也应开展汞含量水平的调查。

Alpha-Tomatin against Witches’Broom Disease

Several plants use secondary metabolites against insects and pathogens attack. Among such metabolites known glycoalkaloids are the most studied. Plants from Solanaceae Family are the most abundant on those alkaloids. Despite alfa-tomatine is a known glycoalkaloid, its specific action against Moniliophthora perniciosa, fungi responsible for witches broom disease in cocoa plantations was obtained in this work. Alfa-tomatine was infusion-extracted from Solanum lycopersicum leaves, and its action against the fungi growth was shown on the bioassays. In these tests, M. perniciosa growth was totally inhibited but other fungus tested, the inhibition was not totally, or did not present effect on growth, showing in this way, the specificity of alfa-tomatine to M. perniciosa. The advantages of work with a natural molecule for the fungi control is the stability of the molecule, its resistance to high temperature and pressure and for its use, the simple method of extraction used. The confirmation of the alfa-tomatine molecule was done by High Performance Liquid Chromatography and Mass Spectrometry in comparison to the Sigma standard.

Guarding tomato fruit setting in adverse temperatures through the miRNA166-S/HBt5A regulatory module

Fruits are defined as mature ovaries originated from a coordinated development between ovules(precursors of seeds)and carpels(precursors of the fruit body).Disconnecting the ovule development from carpel development is a long-desired goal in agriculture to generate seedless fruits easier to consume.However,pollination and fertilization are required to promote hormone pathways-i.e.,auxin and gibberellin-that are crucial for seed and fruit set(Gillaspy et al.,1993;Raghavan,2003).Even though developing seeds are central for normal fruit development,examples of seedless or parthenocarpic fruits are present in wild and cultivated species(Joldersma and Liu,2017).

Increased branching independent of strigolactone in cytokinin oxidase 2-overexpressing tomato is mediated by reduced auxin transport

Tomato production is influenced by shoot branching,which is controlled by different hormones.Here we produced tomato plants overexpressing the cytokinin-deactivating gene CYTOKININ OXYDASE 2(CKX2).CKX2-overexpressing(CKX2-OE)plants showed an excessive growth of axillary shoots,the opposite phenotype expected for plants with reduced cytokinin content,as evidenced by LC-MS analysis and ARR5-GUS staining.The TCP transcription factor SlBRC1b was downregulated in the axillary buds of CKX2-OE and its excessive branching was dependent on a functional version of the GRAS-family gene LATERAL SUPPRESSOR(LS).Grafting experiments indicated that increased branching in CKX2-OE plants is unlikely to be mediated by root-derived signals.Crossing CKX2-OE plants with transgenic antisense plants for the strigolactone biosynthesis gene CAROTENOID CLEAVAGE DIOXYGENASE(CCD7-AS)produced an additive phenotype,indicating independent effects of cytokinin and strigolactones on increased branching.On the other hand,CKX2-OE plants showed reduced polar auxin transport and their bud outgrowth was reduced when combined with auxin mutants.Accordingly,CKX2-OE basal buds did not respond to auxin applied in the decapitated apex.Our results suggest that tomato shoot branching depends on a fine-tuning of different hormonal balances and that perturbations in the auxin status could compensate for the reduced cytokinin levels in CKX2-OE plants.

What a few hairs can tell us about the resource use of giant armadillos

Understanding of resource requirements of vulnerable species is key for conservation planning.Here,we used sta-ble carbon(δ13C)and nitrogen isotopes(δ15N)of hair from giant armadillos(Priodontes maximus)to understand individual resource use.We collected hair from 19 giant armadillos analyzing 34 samples from the Brazilian Pan-tanal and compared the resource use between sexes and age classes.We also assessed the relationship of isotopic values with individuals’body mass and the habitat type used.We observed a wide variation in resource use by giant armadillos,showing that individuals consume prey that feeds on distinct resources and occupies different habitat types,indicating that there is individual variation in foraging behavior.Most giant armadillos presented a mixed diet(C3/C4 resources,forests/open areas),but a quarter of individuals had strictly C4 diets(open areas).Males are more prone to forage on C4 resources,presenting an isotopic niche 2.6-times larger than that of females.Subadults presented diets more associated with habitats with high arboreal cover(C3 resources,forests),while adults foraged more in open areas(C4 resources).This result is mirrored by the positive relationship betweenδ13C values and body mass,suggesting that larger giant armadillos tend to feed more in open areas.We observed thatδ13C values decreased as individuals increased the use of habitats with high arboreal cover.We stress the importance of con-serving the natural mosaic in the Pantanal landscape for the species persistence,given that giant armadillos require all habitat types to fulfill their dietary,spatial,and developmental needs.

Amazonian Dark Earth and Its Black Carbon Particles Harbor Different Fungal Abundance and Diversity

Amazonian Dark Earth(ADE) is a highly fertile soil of anthropogenic origin characterized by high levels of charred black carbon(BC). It is considered a model of fertility; however, knowledge on the fungal community structure and diversity inhabiting ADE and its BC particles is scarce. Fungal community structure and diversity of ADE and its BC from four sites under different land uses(three agricultural systems and a secondary pristine forest) in the Brazilian Central Amazon were evaluated by 18S rRNA gene pyrosequencing. Fungal communities in ADE and BC were dissimilar and showed differential abundances of fungal operational taxonomic units(OTUs). Estimated fungal species richness(abundance-based coverage estimate and Chao-1 index) and diversity estimators(Shannon and Simpson's reciprocal indices) were higher in ADE than in BC in all agricultural areas. No differences were observed in those parameters in ADE and BC samples from the secondary forest. Pezizomycotina fungi and OTUs assigned to Cordyceps confragosa,Acremonium vitellinum, Camarops microspora, and Hirsutella rhossiliensis were more abundant in BC particles than in ADE. These findings represent a breakthrough in our understanding of fungal communities in BC particles from ADE, and will be valuable in future studies considering biochar application in soil.