Produção de frutos de cafeeiros (Coffea arabica L.) em diferentes posições e orientaçoes de ramos plagiotrópicos

This paper aimed at to evaluate the fruit production in different positions of coffee plagiotropic shoot (Coffea arabica L.), during eight months. Measurements started in October 21 taking five different regions of eight shoots located in the central region of a plant belonging to the cultivar of Rubi MG 1192; located at the Coffee Section from the Federal University of Lavras. The experimental design used was random blocks disposed in factorial scheme, 2x 4x 8, composed by two positions(upper third and lower third), four orientations (east sunrise, west sunset, north and south) and eight evaluations time (from October 2005 to May 2006), totalizing 64 treatments, containing 10 replicates and one plant per plot. There was a reduction in fruit number per shoot during the development and this fact was more proeminent in shoots located in the inferior part of the plant and in period from December to January. The orientations North, South, East and West did not influence the number of fruits during the development. Com o objetivo de avaliar a produção de frutos em diferentes posições de ramos plagiotrópicos em cafeeiros (Coffea arabica L.) levando em consideração os pontos cardeais, foram feitas oito avaliações mensais, iniciadas em 21 de outubro, de todos os componentes de cinco rosetas centrais em oito ramos em 10 plantas em uma lavoura da cultivar Rubi MG 1192, instalada no Setor de Cafeicultura no Campus da Universidade Federal de Lavras. O experimento foi instalado utilizando o delineamento em blocos casualizados em esquema fatorial 2 x 4 x 8 constituído de duas posições (terço superior e terço inferior), quatro orientações (leste, oeste, norte e sul) e oito épocas de avaliações (de outubro de 2005 a maio de 2006), totalizando 64 tratamentos, com 10 repetições e uma planta por parcela. Houve acentuada redução no número de frutos por roseta do cafeeiro durante o desenvolvimento da planta, sendo essa redução mais proeminente nos ramos inferiores e no período de dezembro a janeiro. As orientações Norte, Sul, Leste e Oeste não influenciam o número de frutos por roseta durante o desenvolvimento.

Atividade de invertases e sacarose sintase em plantas de cafeeiro pulverizadas com solução de sacarose

Uma prática cuja eficiência não foi ainda comprovada cientificamente, é a pulverização dos cafeeiros com solução diluída de sacarose, como fonte de carbono para as plantas. Este trabalho visou estudar o efeito da pulverização de açúcar via folha nos teores endógenos de carboidratos e na atividade das enzimas invertases e sacarose sintase em mudas de cafeeiros (Coffea arabica L.) com baixo (baixo) e alto (normal) nível de reservas de carbono. As pulverizações ocorreram nas concentrações de 0,5 e 1% de sacarose utilizando-se água como testemunha. A aplicação de sacarose a 1% aumentou a concentração de açúcares solúveis totais (AST) em plantas depauperadas, como também aumentou as atividades das enzimas invertase ácida da parede, invertase ácida do vacúolo, invertase neutra do citosol e sacarose sintase. Em plantas com níveis normais de carboidratos não foi observada nenhuma alteração nos teores dos AST, como também nas atividades de tais enzimas. Independentemente dos tratamentos aplicados e do estado fisiológico das plantas, não foram observadas diferenças na transpiração e na condutância estomática, mostrando, desta forma, o controle estomático da transpiração. A fotossíntese foi estimulada a 0,5% e 1% em plantas depauperadas, o que não aconteceu com plantas normais. A pulverização de sacarose em mudas de cafeeiros só é eficiente tratando-se de plantas depauperadas na concentração de 1%.One management practice of which the efficiency has not yet been scientifically tested is spraying coffee plants with diluted sucrose solutions as a source of carbon for the plant. This paper evaluates the effect of foliar spraying with sugar on the endogenous level of carbohydrates and on the activities of invertase and sucrose synthase in coffee (Coffea arabica L.) seedlings with reduced (low) and high (normal) levels of carbon reserve. The concentrations used were 0.5 and 1.0% sucrose, and water as a control. The use of sucrose at 1.0% caused an increase in the concentration of total soluble sugars in depauperate plants, as well as increased the activity of the following enzymes: cell wall and vacuole acid invertase, neutral cytosol invertase and sucrose synthase. In plants with high level of carbon reserve, no increments in total soluble sugar levels or in enzymatic activity were observed. Regardless of treatments or plants physiological state, no differences in transpiration or stomatal conductance were observed, demonstrating the stomatal control of transpiration. Photosynthesis was stimulated with the use of 0.5 and 1.0 % sucrose only in depauperate plants. Coffee seedling spraying with sucrose is only efficient for depauperate plants, at the concentration of 1.0%

Flooding tolerance and cell wall alterations in maize mesocotyl during hypoxia

A "plastic strain gradient" version of an isotropic elastoplastic damage model that depends on the third invariant J(3) of the stress deviator is developed. The model is based on the "non-local" equivalent plastic strain e(p) defined by Peerlings et al. (2001) and Engelen et al. (2003) and introduces a "material length" l to the constitutive equations. It is shown that the non-local equivalent plastic strain e(p) at a material point P can be identified with the average value of the local von Mises equivalent plastic strain (epsilon) over bar (p) over a sphere centered at P and of radius approximately equal to 3 l. A methodology for the numerical integration of the constitutive equations is presented. The algorithm is appropriate for rate-independent as well as rate-dependent (viscoplastic) models. The model is implemented in the ABAQUS general-purpose finite element program and both quasi-static and dynamic problems are solved. Two possible ABAQUS implementations are discussed. First,"user elements" are developed, which can be used for the solution of both quasi-static and dynamic problems. Reduced 1-point Gauss integration is discussed in 8-node hexahedral elements and the "physical stabilization" method of Puso (2000) is used to remove the resulting numerical singularities (hourglass control). Second, the implementation of the model via "user material" subroutines is discussed. Quasi-static problems can be solved with ABAQUS/Standard using a *COUPLED TEMPERATURE-DISPLACEMENT, STEADY STATE analysis together with user subroutine UMAT, in which temperature is identified with the non-local equivalent plastic strain e(p); the solution of dynamic problems requires use of ABAQUS/Explicit together with a *DYNAMIC TEMPERATURE-DISPLACEMENT analysis option and user subroutines VUMAT and DFLUX. Several example problems are solved. (C) 2019 Elsevier Ltd. All rights reserved.Peer reviewe

Flooding tolerance and cell wall alterations in maize mesocotyl during hypoxia

Objetivou-se caracterizar a tolerância ao alagamento e alterações nas frações pécticas e hemicelulósicas de mesocótilos de milho submetidos à hipoxia. Sementes de milho cultivar Saracura BRS-4154 e BR 107, tolerante e sensível à hipoxia, respectivamente, foram submetidas à germinação e a sobrevivência das plântulas em condições de hipoxia, foi avaliada durante cinco dias. O material de parede celular, obtido de segmentos de mesocótilos da cultivar Saracura BRS-4154 com diferentes intensidades de danos causados por hipoxia, foi submetido a fracionamento com oxalato de amônio 0,5% e KOH 2M e 4M. As frações de parede celular obtidas foram analisadas por cromatografia em gel, cromatografia gasosa e espectro de infravermelho com transformação dos dados pela série de Fourrier (FTIR). Períodos de hipoxia superiores a três dias causaram a lise celular (aparência translúcida), e, em estádios mais avançados, a morte das plantas. O perfil gélico das frações pécticas, hemicelulose 2M e 4M das amostras de mesocótilos translúcidos e com constrição apresentaram compostos de baixos pesos moleculares semelhantes à glicose. Os principais açúcares neutros nas frações pécticas e hemicelulósicas foram arabinose, xilose e manose. O espectro de FTIR mostrou um decréscimo gradual nas substâncias pécticas do mesocótilo com aparência normal, para translúcido e constrição respectivamente.This research aimed to characterize the tolerance to flooding and alterations in pectic and hemicellulose fractions from mesocotyl of maize tolerant to flooding when submitted to hypoxia. In order to characterize tolerance seeds from maize cultivars Saracura BRS-4154 and BR 107 tolerant and sensitive to low oxygen levels, respectively, were set to germinate. Plantlet survival was evaluated during five days after having been submitted to hypoxia. After fractionation with ammonium oxalate 0.5% (w/v) and KOH 2M and 4M, Saracura BRS-4154 cell wall was obtained from mesocotyl segments with different damage intensities caused by oxygen deficiency exposure. The cell wall fractions were analyzed by gel filtration and gas chromatography, and also by Infrared Spectrum with Fourrier Transformation (FTIR). The hypoxia period lasting three days or longer caused cell lysis and in advanced stages plant death. The gelic profile from pectic, hemicellulose 2M and 4M fractions from samples with translucid and constriction zone showed the appearance of low molecular weight compounds, similar to glucose. The main neutral sugars in pectic and hemicellulose fractions were arabinose, xilose and mannose. The FTIR spectrum showed a gradual decrease in pectic substances from mesocotyl with normal to translucid and constriction appearance respectively

PROTEIN OXIDATION AND LIPID PEROXIDATION OF SEVERAL ‘SARACURA’MAIZE SELECTION CYCLES UNDER CONTINUOUS FLOODING

This work aimed at studying, under continuous flooding, biochemicalmechanisms such as total protein concentration, proteic oxidation, and membrane lipidperoxidation in leaf and root of the maize BRS 4154 (Saracura) seedlings, after 1 (C1), 8(C8) and 16 (C16) selection cycles under intermittent flooding. The variety BR 107 wasused as control. Seeds of the selection cycles from Saracura: C1, C8 and C16, and controlBR 107 were sowed with the embryo facing up, 1 cm deep, in perforated 200 ml plasticcups filled with lowland soil. The treatments were composed of the periods 0 h (withoutflooding) 8, 24, 48, 72, 96, 120 and 144 h under continuous flooding, using distilledwater up to the soil surface. Protein oxidation and concentration, root and leaf lipid peroxidation were responsive to flooding, showing the same tendency in all genotypesanalyzed

Intragenic antimicrobial peptides (IAPs) from human proteins with potent antimicrobial and anti-inflammatory activity

Following the treads of our previous works on the unveiling of bioactive peptides encrypted in plant proteins from diverse species, the present manuscript reports the occurrence of four proof-of-concept intragenic antimicrobial peptides in human proteins, named Hs IAPs. These IAPs were prospected using the software Kamal, synthesized by solid phase chemistry, and had their interactions with model phospholipid vesicles investigated by differential scanning calorimetry and circular dichroism. Their antimicrobial activity against bacteria, yeasts and filamentous fungi was determined, along with their cytotoxicity towards erythrocytes. Our data demonstrates that Hs IAPs are capable to bind model membranes while attaining α-helical structure, and to inhibit the growth of microorganisms at concentrations as low as 1μM. Hs02, a novel sixteen residue long internal peptide (KWAVRIIRKFIKGFISNH2) derived from the unconventional myosin 1h protein, was further investigated in its capacity to inhibit lipopolysaccharide-induced release of TNF-α in murine macrophages. Hs02 presented potent anti-inflammatory activity, inhibiting the release of TNF-α in LPSprimed cells at the lowest assayed concentration, 0.1 μM. A three-dimensional solution structure of Hs02 bound to DPC micelles was determined by Nuclear Magnetic Resonance. Our work exemplifies how the human genome can be mined for molecules with biotechnological potential in human health and demonstrates that IAPs are actual alternatives to antimicrobial peptides as pharmaceutical agents or in their many other putative applications