Arabidopsis in the wild—the effect of seasons on seed performance

Climate changes play a central role in the adaptive life histories of organisms all over the world. In higher plants, these changes may impact seed performance, both during seed development and after dispersal. To examine the plasticity of seed performance as a response to environmental fluctuations, eight genotypes known to be affected in seed dormancy and longevity were grown in the field in all seasons of two years. Soil and air temperature, day length, precipitation, and sun hours per day were monitored. We show that seed performance depends on the season. Seeds produced by plants grown in the summer, when the days began to shorten and the temperature started to decrease, were smaller with deeper dormancy and lower seed longevity compared to the other seasons when seeds were matured at higher temperature over longer days. The performance of seeds developed in the different seasons was compared to seeds produced in controlled conditions. This revealed that plants grown in a controlled environment produced larger seeds with lower dormancy than those grown in the field. All together the results show that the effect of the environment largely overrules the genetic effects, and especially, differences in seed dormancy caused by the different seasons were larger than the differences between the genotypes.</p

Changes in seed quality during fruit maturation of sweet pepper

Studies regarding seed maturation are important to determine the ideal fruit development stage for harvesting in order to obtain high-quality seeds. Changes in sweet pepper (Capsicum annuum L.) seed quality were monitored during seed development in order to identify the stage of maximum quality of the seeds and the optimum harvest date. Fruits harvested from 20 to 75 days after anthesis (DAA) with step of five days were grouped according to maturity stage (green, yellow, red and intense red color outside). Before seed extraction, the fruit weigh, diameter and length were determined. Seed water content, seed dry weight, 1.000-seed weight, germination, first count, speed emergence index, seedling length, accelerated aging and electrical conductivity tests were performed. Mass maturity of the seeds was attained at 75 DAA, when seed water content was 47.3 % and the fruits were red. Sweet pepper seeds with high germination and vigour should be harvested when fruits are completely red outside, at 75 DAA

Is obesity associated with taste alterations? a systematic review

BackgroundObesity is a growing chronic public health problem. The causes of obesity are varied, but food consumption decisions play an important role, especially decisions about what foods to eat and how much to consume. Food consumption decisions are driven, in part, by individual taste perceptions, a fact that can influence eating behavior and, therefore, body mass.MethodologyThe searches were conducted in the electronic databases PubMed, Web of Science, Scopus, Lilacs, and the grey literature (Google Scholar and Open Grey). The acronym PECO will be used, covering studies with adult humans (P) who have obesity (E) compared to adult humans without obesity (C), having as an outcome the presence of taste alterations (O). After searching, duplicates were removed. The articles were first evaluated by title and abstract, following the inclusion and exclusion criteria; then, the papers were read in full. After the studies were selected, two reviewers extracted the data and assessed the individual risk of bias and control statements for possible confounders and bias consideration. The narrative GRADE system performed the methodological quality assessment using the New Castle Ottawa qualifier and analysis of certainty of evidence.ResultsA total of 3782 records were identified from the database search, of these 19 were considered eligible. Forty percent of the eligible studies show that there was an association between obesity and different taste alterations for different flavors comparing with normal weights adults. In the methodological quality analysis of the nineteen studies, which assesses the risk of bias in the results, fifteen showed good methodological reliability, three showed fair methodological reliability, and one showed low methodological reliability.ConclusionDespite methodological limitations, the results of the studies suggest the existence of a association between obesity and taste alterations, but further investigations with more sensitive methodologies are necessary to confirm this hypothesis.Systematic review registrationhttps://osf.io/9vg4h/, identifier 9vg4h

Efeito do ambiente parental na qualidade de sementes de Arabidopsis thaliana

A qualidade de sementes é determinada pela combinação de fatores gentéticos, físicos, viabilidade, vigor, uniformidade, dormência e longevidade. É adquirida durante o desenvolvimento e maturação da semente, no entanto, condições ambientais desfavoráveis durante esta fase, temperaturas inadequadas, deficit hídrico, falta de nutrientes e luz, podem reduzir a qualidade da semente. O trabalho teve como objetivo analisar a influência do ambiente parental na qualidade da semente, através da aplicação de diferentes concentrações de fosfato e temperaturas, durante o crescimento da planta de Arabidopsis. Para obter uma inicial visão da regulação genética pelos quais o ambiente afeta a qualidade da semente, foi utilizado um conjunto de diferentes genótipos. Primeiro, sementes de genótipo do tipo selvagem Landsberg erecta foram produzidas em sete diferentes concentrações de fosfato (0, 12.5, 50, 500, 2500, 5000 e 50000 &#956;M) a fim de determinar a mais efetiva concentração de fosfato para a produção de sementes. Após esse experimento, as sementes de todo o conjunto de genótipos foram produzidas em três concentrações de fosfato (12.5 &#956;M, 500 &#956;M (condição padrão), 3000 &#956;M) em combinação com duas diferentes temperaturas de crescimento (20° - condição padrão e 25° C C). Os resultados mostraram que tanto o fosfato como a tempetura influenciam a qualidade da semente. Para Columbia background, alta concentração de fosfato durante o desenvolvimento da semente diminuiu a dormência e a longevidade das sementes, determinada pelo teste de deterioração controlada. Alta temperatura de crescimento da planta (25° diminuiu a dormência das C) sementes para os genótipos NILDOG1, NILDOG3 e NILDOG6. Em geral, altos níveis de fosfato durante o desenvolvimento da semente proporcionaram melhor germinação em NaCl, manitol e ABA. A combinação de alta concentração de fosfato e baixa temperatura durante o crescimento da planta resultou em maior acúmulo de fitato e fosfato na semente. Entretanto, estudos adicionais são requeridos para melhor esclarescimento das complexas interações entre fatores ambientais e genéticos que regulam a dormência e a qualidade das sementes.Conselho Nacional de Desenvolvimento Científico e TecnológicoSeed quality is determined by a combination of genetic homogeneity, physical appearance, viability, vigor, uniformity, dormancy and longevity. Seed quality is acquired during seed development and maturation, therefore unfavorable environmental changes during these stages, including the change of temperature, drought stress, lack of nutrients and light, can reduce seed quality. The work presented here analyzes the influence of the parental environment on seed quality, in order to predict seed quality according to growth conditions. To obtain an initial view on the genetic regulation of the environment on seed quality we have used set of different genotypes (standard laboratory genotypes, near isogenic lines and mutants). These plants have be grown in different phosphate concentrations and temperatures. First seeds of wild type Landsberg erecta were grown at seven different phosphate concentrations (0, 12.5, 50, 500, 2500, 5000 and 50000 &#956;M) in order to determine the most effective phosphate concentrations. After this experiment, the whole set of genotypes was grown at three phosphate concentrations (12.5 &#956;M, 500 &#956;M (standard condition), 3000 &#956;M) in combination with two different temperatures (20 oC (standard condition) and 25 oC). The results show that phosphate concentration and temperature both influence seed quality. For the Columbia background, high phosphate levels during seed development decrease seed dormancy and seed longevity as determined by the controlled deterioration test. High parental growth temperature (25° decrease dormancy seeds for genotypes NILDOG1, C) NILDOG3 and NILDOG6. In general, high phosphate levels during seed development provided a better performance of germination in NaCl, mannitol and ABA. The combined effects of high phosphate concentration and low parental growth temperature resulted in the highest phytate and phosphate content in seeds. However, further investigations are required to fully understand the complex interactions between environmental and genetic factors regulating seed dormancy and seed quality

Physiological and biochemical alterations in pepper seeds in maturation state function of fruits

A pesquisa teve por objetivos: i) estudar o processo de maturação das sementes de pimenta (Capsicum annuum L.), variedade Amarela Comprida, para determinação da maturidade fisiológica e definição do ponto adequado para a colheita das sementes. ii) avaliar a influência do estádio de maturação e do armazenamento pós-colheita de frutos na atividade de proteínas LEA (Late embryogeneses accumulated) e na qualidade fisiológica de sementes de pimenta. iii) avaliar alterações fisiológicas e enzimáticas em sementes de pimenta obtidas de frutos colhidos em diferentes estádios de maturação e submetidos ao armazenamento pós- colheita. Para tanto, foi conduzido um experimento em campo, onde foram colhidos frutos aos 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70 e 75 dias após a antese (DAA). Os frutos colhidos aos 40, 50, 60 e 70 DAA foram submetidos ao armazenamento pós-colheita por 0, 3, 6, 9, 12 e 15 dias. Os frutos foram avaliados em relação ao peso, diâmetro, comprimento e número de sementes por fruto. As sementes, após serem extraídas dos frutos, foram submetidas aos seguintes testes e determinações: grau de umidade, massa de matéria seca por semente, peso de mil sementes, germinação, primeira contagem de germinação, índice de velocidade de emergência, comprimento de plântula, deterioração controlada, envelhecimento acelerado e condutividade elétrica. Foram determinados ainda os padrões eletroforéticos das seguintes enzimas: Peroxidase (PO), Superóxido Dismutase (SOD), Malato Desidrogenase (MDH), Álcool Desidrogenase (ADH) e de proteínas LEA. Utilizou-se o delineamento inteiramente casualizado, com quatro repetições, sendo os dados submetidos à análise de variância e de regressão. A maturidade fisiológica das sementes de pimenta, cv. Amarela Comprida ocorre aos 70 DAA, quando as sementes possuíam teor de água de 46%. A qualidade fisiológica das sementes foi máxima entre 65 e 70 DAA, quando os frutos estavam com a cor vermelha e vermelha intensa, respectivamente, indicando que a colheita deve ser feita a partir desta faixa. Colheitas precoces (40 DAA) não são benéficas à qualidade fisiológica das sementes de pimenta, mesmo quando associadas a um período de armazenamento pós-colheita dos frutos por até 15 dias. Para frutos colhidos aos 50 DAA, o armazenamento pós-colheita por 12 dias é imprescindível para melhoria da qualidade fisiológica das sementes. Sementes de pimenta colhidas a partir dos 60 DAA apresentam alta qualidade fisiológica, não sendo necessário o armazenamento dos frutos após a colheita. A síntese de proteínas LEA ocorre a partir de 60 DAA, estando diretamente relacionada com a qualidade fisiológica de sementes de pimenta. Maior atividade das enzimas ADH e SOD foram constatadas em sementes obtidas de frutos colhidos aos 60 e 70 DAA, independente do período de armazenamento pós-colheita.The present research had objectives: i) to study the maturation process of pepper seeds (Capsicum annuum L.), Amarela Comprida variety, aiming to determine the physiological maturity of seeds and the adequate moment for seed harvest. ii) to evaluate the influence of maturation state and post-harvest storage of fruits in LEA (Late embryogeneses accumulated) proteins activity and physiological quality of seeds; iii) to evaluate physiological and enzymatic alterations in pepper seeds harvested at different maturation state and submitted to post-harvest storage of fruits. An experiment was conducted in the field and fruits were harvested at 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70 and 75 days after anthesis (DAA). The fruits harvested at 40, 50, 60 and 70 DAA were stored for 0, 3, 6, 9, 12 and 15 days. Then fruits were appraised in relation to the weigh, diameter, length and number of seeds per fruit. The seeds were submitted to the following tests and determinations: moisture content, dry matter, weight of thousand seeds, germination, first count of germination, speed emergence index, seedling length, controlled deterioration, accelerated aging and electrical conductivity. Isoenzimatic patterns of Peroxidase, Superoxide Dismutase, Malate Desidrogenase, Alcohol Desidrogenase and LEA proteins were determined by electrophoretic analysis. The experiment was conduted in completely randomized design, with four replications, and the data were submitted to variance analysis and regression. The physiological maturity of pepper seeds, cv. Amarela Comprida , happened at 70 DAA, when the seeds presented 46.1% moisture content. The maximum physiological quality of seeds occurred between 65 and 70 DAA, indicating that harvest can be made in this period. Precocious harvest (40 DAA) was not beneficial to physiological quality of seeds when associated to 15 days post-harvest storage. For fruits harvested at 50 DAA, post- harvest storage of fruit for 12 days was indispensable to assure the physiological quality of seeds. Pepper seeds harvested from 60 DAA presented high physiological quality, not being necessary the post- harvest storage of fruits. The LEA proteins synthesis occurred at 60 DAA, being directly related to physiological quality of seeds. Higher activity of Alcohol Desidrogenase and Superoxide Dismutase enzymes were verified in the seeds obtained from fruits harvested at 60 and 70 DAA, regardless post-harvest storage.Conselho Nacional de Desenvolvimento Científico e Tecnológic

Equação de longevidade para sementes de jabuticaba

Objetivou-se equacionar o desvio padrão da frequência de distribuição de sementes mortas de jabuticaba durante o período de armazenamento (σ), com base no modelo de probit. Valores obtidos experimentalmente, adicionados a dados da literatura de curvas de sobrevivência de sementes de jabuticaba, armazenadas sob diferentes teores de água e temperaturas, foram transformados em probit e utilizados em regressões lineares e não lineares para determinação dos coeficientes de equação de longevidade. Os coeficientes da melhor equação obtida foram determinados usando os valores da perda de germinação, da germinação inicial no lugar de Ki, da temperatura, do teor médio de água das sementes e do período de armazenagem, para todas as curvas de sobrevivência, conforme segue: σ = 10^ ( f0 + f1 m + f2 m2 + f3 m3 + f4 t2 + f5 m.t ) em que: f 0 = -98,349, f 1 = 6,0973, f 2 = -0,12224, f 3 = 0,00081249, f 4 = 0,058075, f 5 = -0,0099939. A equação obtida foi ajustada com razoável precisão (coeficiente de determinação de 0,873, desvio padrão de 12,3% e grau de significância dos coeficientes da equação menor que 0,1% de probabilidade de erro no teste t, para 72 observações experimentais).The objective of this study was to equate the standard deviation of the frequency distribution of dead jabuticaba seed during the storage period (σ), based on the probit model. Experimentally obtained values, summed with data from literature on the survival curves of jabuticaba seeds, stored under different moisture contents and temperatures, were transformed into probit values and used in linear and non-linear regressions for determining the coefficients of the longevity equation. The coefficients of the best equation obtained were determined using the values of germination loss, initial germination in the place of Ki, temperature, average moisture content of the seeds and the storage period for all survival curves as follows: σ = 10 ( f0 + f1 m + f2 m + f3 m + f4 t + f5 m.t ) where: f 0 = -98.349, f 1 = 6.0973, f 2 = -0.12224, f 3 = 0.00081249, f 4 = 0.058075, f 5 = -0.0099939. The obtained equation was fitted with reasonable precision (adjusted linear determination coefficient of 0.873, standard error of 12.3% germination, and all significance of the equation coefficients less than 0.1% probability in the t-test, for 72 experimental data)

Maturação de sementes de tomate em função da ordem de frutificação na planta

A pesquisa teve por objetivos estudar o processo de maturação de sementes de tomate (Lycopersicon lycopersicum L.) buscando caracterizar a maturidade fisiológica das sementes extraídas de frutos colhidos nos racimos 1, 3 e 5, nas posições proximal e distal. Os frutos foram colhidos aos 30, 40, 50, 60, 70, 80 e 90 dias após a antese (DAA), determinando-se também o acúmulo de unidades térmicas, em graus dias (GD), durante esses respectivos intervalos de tempo. Determinou-se o peso de sementes por fruto bem como o peso de matéria seca, germinação, primeira contagem de germinação, porcentagem e índice de velocidade de emergência de plântulas, deterioração controlada e condutividade elétrica. Não houve diferença entre racimos quanto à época da maturidade fisiológica das sementes, que ocorreu cerca de 750 GD ou 75 DAA. A germinação mais elevada ocorreu antes do acúmulo máximo de matéria seca na semente; o máximo vigor ocorreu, quando os frutos se encontravam com 90% do pericarpo vermelho, próximo ou após a máxima matéria seca.This work aimed to study the maturation of tomato (Lycopersicon lycopersicum L.) seeds, characterizing the physiological maturity of seeds extracted from fruits harvested at trusses 1, 3 and 5, at proximal and distal positions. Fruits were harvested at 30, 40, 50, 60, 70, 80 e 90 days after anthesis (DAA). For the same period, the thermal accumulation in heat units (HU) was also registered. Determinations were performed to quantify the total seed weight per fruit, seed moisture content, average dry weight of seeds, germination rate, and vigor (germination first count, controlled deterioration, seedling emergence and electrical conductivity). There were no differences among trusses regarding seed physiological maturity, which was attained at 750 HU or 75 DAA. Maximum seed germination occurred before maximum seed dry weight was achieved, and the highest seed vigor occurred at or after maximum seed dry weight was achieved, when the fruit’s exocarp was 90% red

Altitudinal and climatic associations of seed dormancy and flowering traits evidence adaptation of annual life cycle timing in Arabidopsis thaliana

The temporal control or timing of the life cycle of annual plants is presumed to provide adaptive strategies to escape harsh environments for survival and reproduction. This is mainly determined by the timing of germination, which is controlled by the level of seed dormancy, and of flowering initiation. However, the environmental factors driving the evolution of plant life cycles remain largely unknown. To address this question we have analysed nine quantitative life history traits, in a native regional collection of 300 wild accessions of Arabidopsis thaliana. Seed dormancy and flowering time were negatively correlated, indicating that these traits have coevolved. In addition, environmental-phenotypic analyses detected strong altitudinal and climatic clines for most life history traits. Overall, accessions showing life cycles with early flowering, small seeds, high seed dormancy and slow germination rate were associated with locations exposed to high temperature, low summer precipitation and high radiation. Furthermore, we analysed the expression level of the positive regulator of seed dormancy DELAY OF GERMINATION 1 (DOG1), finding similar but weaker altitudinal and climatic patterns than seed dormancy. Therefore, DOG1 regulatory mutations are likely to provide a quantitative molecular mechanism for the adaptation of A. thaliana life cycle to altitude and climate.</p

Changes in seed quality during fruit maturation of sweet pepper

Studies regarding seed maturation are important to determine the ideal fruit development stage for harvesting in order to obtain high-quality seeds. Changes in sweet pepper (Capsicum annuum L.) seed quality were monitored during seed development in order to identify the stage of maximum quality of the seeds and the optimum harvest date. Fruits harvested from 20 to 75 days after anthesis (DAA) with step of five days were grouped according to maturity stage (green, yellow, red and intense red color outside). Before seed extraction, the fruit weigh, diameter and length were determined. Seed water content, seed dry weight, 1.000-seed weight, germination, first count, speed emergence index, seedling length, accelerated aging and electrical conductivity tests were performed. Mass maturity of the seeds was attained at 75 DAA, when seed water content was 47.3 % and the fruits were red. Sweet pepper seeds with high germination and vigour should be harvested when fruits are completely red outside, at 75 DAA