Metodos para reduzir o tempo de germinacao de sementes de bacuri (Platonia insignis Mart.).

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Métodos para reduzir o tempo de germinação de sementes de bacuri (Platonia insignis Mart.).

Este trabalho teve como objetivo avaliar métodos para acelerar a germinação de sementes de bacuri (Platonia insignis Mart.). O experimento foi conduzido no Laboratório de Fisiologia Vegetal e na Câmara de Nebulização da Embrapa Meio-Norte, Teresina-PI, no delineamento de blocos ao acaso, com dez tratamentos e quatro repetições, sendo a unidade experimental constituída por dez sementes. Foram testados os seguintes tratamentos: testemunha (Tl); remoção do tegumento da semente (T2); remoção do meristema fundamental corticai, através de cortes em planos perpendiculares ao plano dorsalíventd, nos dois lados da semente, sem atingir o menstema fundamental medular (T3); T3 mais a remoção do meristema fundamental cortical através de cortes em planos paralelos ao plano dorsai-.ventrai, na região dorsal, sem atingir o menstema fundamental medular (T4); T3 mantido em água a 40 "C por 20 minutos (T5); T4 mantido em água a 40 'C por 20 minutos (T6); T3 mantido em etanol 80% por 5 minutos (T7); T4 mantido em etanol 80% por 5 minutos (T8); T3 mantido em acetona 80% por 5 minutos (T9); e T4 mantido em acetona 80% por 5 minutos (TIO). As variáveis estudadas foram: percentagem de emergência da radícula aos 14 (PErl4), 2 1 (PEr2 l), 28 (PEr28), e 35 (PEr35) dias após a semeadura e índice de velocidade de emergência da radicula (IVEr) no 35' dia após a semeadura. As sementes submetidas aos tratamentos T2, T3, T4, T5 e T6 apresentaram PErl4 de 72,5%; 65,0%; 72,5%; 52,5% e 67,5%, respectivamente, sendo superiores (p<0,05) aos demais tratamentos. Todos os tratamentos foram superiores @<0,05) a testemunha em relação a PEr21 (35,0%) e não houve diferença significativa entre os tratamentos em relação a PEr28 e PEr35. Quanto ao IVEr, os tratamentos T2, T3, T4, T5 e T6 apresentaram os valores de 0,59; 0,57; 0,61; 0,54 e 0,59, respectivamente, superando (p<0,05) os demais tratamentos, os quais não diferiram da testemunha (0,36).bitstream/item/35780/1/BP25.pd

Cadeia produtiva do mel de abelhas do Piauí.

Introdução; Produção de mel no Brasil e no Piauí; Organização dos apicultores; Importância sócio-econômica; Empregos indiretos; Demanda; Agentes de crédito e comercialização; Oportunidades e gargalos; Tendências da cadeia; Referências bibliográficas

Avaliacao agronomica de fruteiras nativas do Meio-Norte do Brasil.

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Relatório final do convênio EMBRAPA/CIL. (Germinação de bacuri).

O trabalho teve como objetivo avaliar metodos simples para acelerar e uniformizar a germinacao de sementes de bacuri, sendo os tratamentos comparados com a testemunha quanto a percentagem de emergencia de radiculas ao 14 (PEr14), 21 (PEr21), 28 (PEr28) e 35 (PEr35) dias, indice de velocidades de emergencia de radiculas (IVEr), comprimento de radiculas (Cr), percentagem de emergencia de cauliculo (PEc), indice de velocidade de emergencia de cauliculo (IVEc) e o comprimento, diametro e numero de plantulas. Os resultados obtidos sao bastante promissores no sentido de reduzir o tempo para formacao de mudas de bacuri via sementes, visto a obtencao de um indice medio de 66,5% de emissao de radiculas ao 14 dias, enquanto no processo natural, essa percentagem e de apenas 20%. As radiculas assim produzidas podem entao ser utilizadas utilizadas no processo de producao de mudas via estacas de radiculas. Por outro lado, o tratamento 10 obteve 10% de emergencia de cauliculo aos 150 dias, enquanto no processo natural esse indice e de 6%

Repetibility of the yield traits of Brazil nut cultivated in Roraima.

The objective of this study was to estimate the spatial repeatability coefficients of Bertholletia excelsa fruits and nuts using different statistical methods, as well as to define the minimum number of fruits and nuts to be evaluated for the selection of superior genotypes. Twenty-one genotypes in the 2017 crop and 28 genotypes in the 2018 crop were evaluated. From each genotype, 10 fruits and 10 nuts per fruit were sampled. Seven fruit traits and three nut traits were measured, which were used to estimate repeatability coefficients by four statistical methods: 1) analysis of variance; 2) main components based on the correlation matrix; 3) principal components based on the covariance matrix and 4) structural analysis based on the correlation matrix. Estimates of repeatability coefficients varied among crops, traits and estimation methods. In general, the coefficients presented moderate magnitudes, and the methods based on principal components provided the highest estimates. For the most economically important traits for the Brazil nut market, minimum sampling of 8 fruits and 7 nuts per genotype is required to select genotypes with determination coefficients above 85%

A holin and an endopeptidase are essential for chitinolytic protein secretion in <i>Serratia marcescens</i>

Pathogenic bacteria adapt to their environment and manipulate the biochemistry of hosts by secretion of effector molecules. Serratia marcescens is an opportunistic pathogen associated with healthcare-acquired infections and is a prolific secretor of proteins, including three chitinases (ChiA, ChiB, and ChiC) and a chitin binding protein (Cbp21). In this work, genetic, biochemical, and proteomic approaches identified genes that were required for secretion of all three chitinases and Cbp21. A genetic screen identified a holin-like protein (ChiW) and a putative l-alanyl-d-glutamate endopeptidase (ChiX), and subsequent biochemical analyses established that both were required for nonlytic secretion of the entire chitinolytic machinery, with chitinase secretion being blocked at a late stage in the mutants. In addition, live-cell imaging experiments demonstrated bimodal and coordinated expression of chiX and chiA and revealed that cells expressing chiA remained viable. It is proposed that ChiW and ChiX operate in tandem as components of a protein secretion system used by gram-negative bacteria

Protein methyltransferase 7 deficiency in Leishmania major increases neutrophil associated pathology in murine model

Leishmania major is the main causative agent of cutaneous leishmaniasis in the Old World. In Leishmania parasites, the lack of transcriptional control is mostly compensated by post-transcriptional mechanisms. Methylation of arginine is a conserved post-translational modification executed by Protein Arginine Methyltransferase (PRMTs). The genome from L. major encodes five PRMT homologs, including the cytosolic protein associated with several RNA-binding proteins, LmjPRMT7. It has been previously reported that LmjPRMT7 could impact parasite infectivity. In addition, a more recent work has clearly shown the importance of LmjPRMT7 in RNA-binding capacity and protein stability of methylation targets, demonstrating the role of this enzyme as an important epigenetic regulator of mRNA metabolism. In this study, we unveil the impact of PRMT7-mediated methylation on parasite development and virulence. Our data reveals that higher levels of LmjPRMT7 can impair parasite pathogenicity, and that deletion of this enzyme rescues the pathogenic phenotype of an attenuated strain of L. major. Interestingly, lesion formation caused by LmjPRMT7 knockout parasites is associated with an exacerbated inflammatory reaction in the tissue correlated with an excessive neutrophil recruitment. Moreover, the absence of LmjPRMT7 also impairs parasite development within the sand fly vector Phlebotomus duboscqi. Finally, a transcriptome analysis shed light onto possible genes affected by depletion of this enzyme. Taken together, this study highlights how post-transcriptional regulation can affect different aspects of the parasite biology