Crop Physiology and Biochemistry Research Papers (original) (raw)

Okra (Abelmoschus esculentus L.) is one of the horticultural crops commonly grown in Zimbabwe but the productivity of the crop is hampered by poor erratic seed germination due to dormancy. A study was carried out at Bindura University of... more

Okra (Abelmoschus esculentus L.) is one of the horticultural crops commonly grown in Zimbabwe but the productivity of the crop is hampered by poor erratic seed germination due to dormancy. A study was carried out at Bindura University of Science Education to determine the best method and treatment
combination of breaking okra seed dormancy. Viability tests and germination tests were conducted first to ascertain that failure of germination was due to dormancy. The study consisted of 3 laboratory experiments arranged as factorial treatment structure laid in a completely randomised design with 3 replications. The 3 experiments consisted of 3 methods of breaking seed dormancy (water soaking, acid scarification and dry heating). Each of the different methods was employed at different exposure duration and at different temperature/concentration levels. Germination was measured for 14 days to determine the total final percentage seed germination. Acid scarified seeds for 3 min at 80% H2SO4
concentration level had the best germination percentage of 96.6% followed by dry heating for 5 minutes at 70°C and soaking for 12 h at 30°C which had 92.2 and 91.3% germination respectively. However, H2SO4 scarification for 5 min at 60% concentration gave the least germination of 44% followed by
soaking for 48 h at 30°C and dry heating for 5 min at 80°C which all resulted in 50% germination. Based on the research findings, 80% H2SO4 for 3 min can be used by okra farmers to break dormancy while dry heating for 5 min at 70°C and soaking for 12 h at 30°C are equally good alternatives.

Previous studies with different results have suggested that total and bioavailable testosterone levels are modified by physical exercise. Such changes may be related to modifications in cortisol levels and could be reflected in some urine... more

Previous studies with different results have suggested that total and bioavailable testosterone levels are modified by physical exercise. Such changes may be related to modifications in cortisol levels and could be reflected in some urine androgens. To determine how weight lifting training may affect serum and urinary androgens, we measured total serum testosterone (T), cortisol, sex hormone binding globulin (SHBG)

Vitamin C is a wide spectrum antioxidant essential for humans, which are unable to synthesize the vitamin and must obtain it from dietary sources. There are two biologically important forms of vitamin C, the reduced form, ascorbic acid,... more

Vitamin C is a wide spectrum antioxidant essential for humans, which are unable to synthesize the vitamin and must obtain it from dietary sources. There are two biologically important forms of vitamin C, the reduced form, ascorbic acid, and the oxidized form, dehydroascorbic acid. Vitamin C exerts most of its biological functions intracellularly and is acquired by cells with the participation of specific membrane transporters. This is a central issue because even in those species capable of synthesizing vitamin C, synthesis is restricted to the liver (and pancreas) from which is distributed to the organism. Most cells express two different transproter systems for vitamin C; a transporter system with absolute specificity for ascorbic acid and a second system that shows absolute specificity for dehydroascorbic acid. The dehydroascorbic acid transporters are members of the GLUT family of facilitative glucose transporters, of which at least three isoforms, GLUT1, GLUT3 and GLUT4, are dehydroascorbic acid transporters. Ascorbic acid is transported by the SVCT family of sodium-coupled transporters, with two isoforms molecularly cloned, the transporters SVCT1 y SVCT2, that show different functional properties and differential cell and tissue expression. In humans, the maintenance of a low daily requirement of vitamin C is attained through an efficient system for the recycling of the vitamin involving the two families of vitamin C transporters.

Fructose is one of the most abundant monosaccharide in nature. It is also the sweetest naturally occurring carbohydrate. Since decades, fructose used for food preparations is not provided by fruit or vegetable but by a chemical process of... more

Fructose is one of the most abundant monosaccharide in nature. It is also the sweetest naturally occurring carbohydrate. Since decades, fructose used for food preparations is not provided by fruit or vegetable but by a chemical process of starch or inulin conversion. We processed a new method of fructose extraction from apple and investigated the acute and long term effect of this carbohydrate on glucose metabolism in C57Bl6/j mice. By using the glycemic index (GI), we have shown that one of the sugars obtained from apple, FructiLight, has a very low impact on glycemic and insulin response during acute treatment compared to other sugars. This carbohydrate, essentially constituted by fructose, has also beneficial properties when administrated for long term treatment. Indeed, as two other sugars extracted from apple (FructiSweetApple and FructiSweet67), FructiLight exposure during 21 weeks in beverage has promoted an enhancement of glucose tolerance compared to glucose treatment without affecting food intake and weight. All these results indicate that apple-extracted sugars and more precisely fructose from these fruits could be a promising way to produce new food and sweet beverages.

Twenty-seven individual tree growth models are reviewed. The models take into account the same main physiological processes involved in carbon metabolism (photosynthate production, respiration, reserve dynamics, allocation of assimilates... more

Twenty-seven individual tree growth models are reviewed. The models take into account the same main physiological processes involved in carbon metabolism (photosynthate production, respiration, reserve dynamics, allocation of assimilates and growth) and share common rationales that are discussed. It is shown that the spatial resolution and representation of tree architecture used mainly depend on model objectives. Beyond common rationales, the models reviewed exhibit very different treatments of each process involved in carbon metabolism. The treatments of all these processes are presented and discussed in terms of formulation simplicity, ability to account for response to environment, and explanatory or predictive capacities. Representation of photosynthetic carbon gain ranges from merely empirical relationships that provide annual photosynthate production, to mechanistic models of instantaneous leaf photosynthesis that explicitly account for the effects of the major environmental variables. Respiration is often described empirically as the sum of two functional components (maintenance and growth). Maintenance demand is described by using temperature-dependent coefficients, while growth efficiency is described by using temperature-independent conversion coefficients. Carbohydrate reserve pools are generally represented as black boxes and their dynamics is rarely addressed. Storage and reserve mobilisation are often treated as passive phenomena, and reserve pools are assumed to behave like buffers that absorb the residual, excessive carbohydrate on a daily or seasonal basis. Various approaches to modelling carbon allocation have been applied, such as the use of empirical partitioning coefficients, balanced growth considerations and optimality principles, resistance mass-flow models, or the source-sink approach. The outputs of carbon-based models of individual tree growth are reviewed, and their implications for forestry and ecology are discussed. Three critical issues for these models to date are identified: (i) the representation of carbon allocation and of the effects of architecture on tree growth is Achilles’ heel of most of tree growth models; (ii) reserve dynamics is always poorly accounted for; (iii) the representation of below ground processes and tree nutrient economy is lacking in most of the models reviewed. Addressing these critical issues could greatly enhance the reliability and predictive capacity of individual tree growth models in the near future

1. Synthetic amyloid β-peptide was toxic to NB41A3 neuroblastoma cells in serum-free culture as judged by decreasing cell numbers and release of the cytosolic enzyme, lactic dehydrogenase.2. Without amyloid β-peptide, bovine serum albumin... more

1. Synthetic amyloid β-peptide was toxic to NB41A3 neuroblastoma cells in serum-free culture as judged by decreasing cell numbers and release of the cytosolic enzyme, lactic dehydrogenase.2. Without amyloid β-peptide, bovine serum albumin increased the number of cells surviving in culture.3. In the presence of amyloid β-peptide, BSA appeared to potentiate the amyloid β-peptide toxicity.4. The toxic dose response for amyloid β-peptide varied between different cell lines (NB41A3, NB2a and IMR32), in a range of 100–1000 nM amyloid β-peptide.5. Amyloid β-peptide toxicity was inhibited by the concurrent treatment of the cells with the tachykinin physalaemin with an ed50 of 10−6M.

Vitamin C is a wide spectrum antioxidant essential for humans, which are unable to synthesize the vitamin and must obtain it from dietary sources. There are two biologically important forms of vitamin C, the reduced form, ascorbic acid,... more

Vitamin C is a wide spectrum antioxidant essential for humans, which are unable to synthesize the vitamin and must obtain it from dietary sources. There are two biologically important forms of vitamin C, the reduced form, ascorbic acid, and the oxidized form, dehydroascorbic acid. Vitamin C exerts most of its biological functions intracellularly and is acquired by cells with the participation of specific membrane transporters. This is a central issue because even in those species capable of synthesizing vitamin C, synthesis is restricted to the liver (and pancreas) from which is distributed to the organism. Most cells express two different transproter systems for vitamin C; a transporter system with absolute specificity for ascorbic acid and a second system that shows absolute specificity for dehydroascorbic acid. The dehydroascorbic acid transporters are members of the GLUT family of facilitative glucose transporters, of which at least three isoforms, GLUT1, GLUT3 and GLUT4, are dehydroascorbic acid transporters. Ascorbic acid is transported by the SVCT family of sodium-coupled transporters, with two isoforms molecularly cloned, the transporters SVCT1 y SVCT2, that show different functional properties and differential cell and tissue expression. In humans, the maintenance of a low daily requirement of vitamin C is attained through an efficient system for the recycling of the vitamin involving the two families of vitamin C transporters.

Aims: To determine the time interval between fruit formation and lignification (hardening of fruits) and phonological traits in three short, early maturing and three tall, late maturing genotypes of Okra (Abelmoschus esculentus L Moench)... more

Aims: To determine the time interval between fruit formation and lignification (hardening of fruits) and phonological traits in three short, early maturing and three tall, late maturing genotypes of Okra (Abelmoschus esculentus L Moench) grown in southern Nigeria. Study Design: Two separate experiments for the dwarf early maturing and tall late maturing genotypes were laid out in a randomized complete block design with five replications. Original Research Article Ubi et al.; IJPSS, 10(2): xxx-xxx, 2016; Article no.IJPSS.23514 2 Place and Duration of Study: The study was conducted in Calabar rainforest agro-ecology in 2014 and 2015 vegetables growing seasons. Methodology: Fruit lignification time interval was determine using the direct time measurement using stop watch and observation of the time interval between fruit formation to time of hardening (Lignification). Data for phenological traits were generated from direct measurements using appropriate tools and observations of okra plants in the field. Results: Results showed that the tall, late maturing okra genotypes required longer time interval to become lignified compared to the dwarf, early maturing genotypes throughout the period of study. Results of time interval measurement showed that significant (p<0.05) differences were detected among genotypes. A time interval of 142±4.50 hours was required for fruit lignification in Perkins long pod, while 'Etighi idok' and 'Okpo-mbontam' genotypes required 124±3.40 and 96±5.15 hours respectively to become lignified. The dwarf, early maturing genotypes, NHAe-47-4 fruits become lignified after 124±3.45 hours, 'Asaka awum' fruits required 121±4.20 hours while Agwu early took 78±3.25 hours to become unusable in fresh conditions. Results of phenological traits of Okra genotypes also revealed that the tall, late maturing genotypes had more branches per plant, more fruits per plant, longer fruiting period and longer days to flower and fruiting initiation compared to the dwarf, early maturing genotypes. Conclusion: Knowledge of fruit lignification time interval in Okra will no doubt reduce the laborious task of daily handpicking of immature fruits, reduce the rate of spoilage of the vegetable, enable for the consumption of fresh rather than dried okra and for plan and controlled harvesting of fruits for the market, income and food security.

Glucose 6-phosphate dehydrogenase is a highly polymorphic enzyme encoded by a human X-linked gene (Xq2.8). This enzyme catalyses the first step of pentose phosphate pathway, that converts glucose 6-phosphate to 6-phosphogluconate with... more

Glucose 6-phosphate dehydrogenase is a highly polymorphic enzyme encoded by a human X-linked gene (Xq2.8). This enzyme catalyses the first step of pentose phosphate pathway, that converts glucose 6-phosphate to 6-phosphogluconate with production of NADPH2. G6PD deficiency is the most common human metabolic inborn error affecting more than 400 million people world wide. The main clinical manifestations are acute hemolytic anemia and jaundice, triggered by infection or ingestion of Fava beans or oxidative drugs. A predominant variant of G6PD named Mediterranean is often associated with favism. This has been evident in several countries including Northern coastal provinces of Iran. Other current variants are Chatham and Cosenza. Molecular identification of the most prevalent mutations in G6PD gene was carried out in 71 males and females with G6PD deficiency. They were from Iranian Northern province of Golestan. DNA was extracted from blood samples and analyzed for known G6PD mutation by PCR and restriction fragment length polymorphisms (RFLP) technique. Adapting this method, revealed that Mediterranean mutation at nt 563 (C→T) is predominant in the area (69%) and 26.7% of patients have Chatham mutation at nt 1003 (G→A). Findings indicate a higher prevalence of these mutations, in Golestan compared to Mazandaran (66.2% Mediterranean and 19% Chatham mutation) and Gilan (86.4% Mediterranean and 9.71% Chatham mutations). Cosenza mutation at nt 1376 (G→C), by PCR-RFLP technique was not found among other 3 samples (4.3%). The similarity of these results with mutations in Italy indicates probable existence of a common ancestral origin in the observed populations. La glucosa-6-fosfato deshidrogenasa (G6PD) es una enzima muy polimórfica codificada en el humano por un gen ubicado en el cromosoma X (Xq2.8). La enzima cataliza el primer paso de la vía de la pentosa fosfato, que convierte la glucosa-6-fosfato en 6-fosfogluconato con producción de NADPH2. La deficiencia en G6PD es el error metabólico congénito mas frecuente en los humanos, afectando a mas de 400 millones de personas en el mundo. Las principales manifestaciones clínicas son anemia hemolítica aguda e ictericia, provocada por infección o ingestión de habas o de productos oxidativos. Una variante muy frecuente de G6PD Ilamada Mediterránea se asocia a menudo con favismo, como se ha encontrado en diversos paises y en las provincias costeras del norte de Irán. Otras variantes son Chatham y Cosenza. En este trabajo, se ha realizado la identificación molecular de las mutaciones mas prevalentes del gen de la G6PD en 71 varones y mujeres con deficiencia en la enzima procedentes de la provincia norteña iraní de Golestan. A partir de ADN extraído de muestras de sangre, se analizó para mutaciones conocidas del gen mediante las técnicas de PCR y RFLP (polimorfismo de restricción de longitud polimórfica). Los resultados mostraron que la mutación en el nucleótido 563 (C→T) es predominante en el área (69%) y que el 26,7% de los pacientes presentan la mutación Chatham en 1003 (G→A). Ello indica una mayor prevalencia de estas mutaciones en Golestan en comparación con Mazandaran (66,2% mutación Mediterránea y 19% Chathman). La mutación Cosenza en 1376 (G→C) es muy poco frecuente (4,3%). La similaridad de estos resultados con las proporciones de las mutaciones encontradas en Italia sugieren la probable existencia de un origen ancestral común.