RESUMO
Polyamines play an important role in growth and differentiation by regulating numerous physiological and biochemical processes at the cellular level. In addition to their roborative effect, their essential role in plant stress responses has been also reported. However, the positive effect may depend on the fine-tuning of polyamine metabolism, which influences the production of free radicals and/or signalling molecules. In the present study, 0.3 mM hydroponic putrescine treatment was tested in wheat, maize, and rice in order to reveal differences in their answers and highlight the relation of these with polyamine metabolism. In the case of wheat, the chlorophyll content and the actual quantum yield increased after putrescine treatment, and no remarkable changes were detected in the stress markers, polyamine contents, or polyamine metabolism-related gene expression. Although, in maize, the actual quantum yield decreased, and the root hydrogen peroxide content increased, no other negative effect was observed after putrescine treatment due to activation of polyamine oxidases at enzyme and gene expression levels. The results also demonstrated that after putrescine treatment, rice with a higher initial polyamine content, the balance of polyamine metabolism was disrupted and a significant amount of putrescine was accumulated, accompanied by a detrimental decrease in the level of higher polyamines. These initial differences and the putrescine-induced shift in polyamine metabolism together with the terminal catabolism or back-conversion-induced release of a substantial quantity of hydrogen peroxide could contribute to oxidative stress observed in rice.
RESUMO
Maize is sensitive to cold injury, especially during germination. Since cold causes oxidative stress, compounds that promote the accumulation of free radical forms, such as the reactive aldehyde (RA) methylglyoxal (MG), may be suitable to trigger a systemic defense response. In this study, maize seeds were soaked in MG solution for one night at room temperature, before germination test at 13°C. The exogenous MG enhanced the germination and photosynthetic performance of maize at low temperature. Transcriptome analysis, hormonal, and flavonoid profiling indicated MG-induced changes in photosystem antenna proteins, pigments, late embryogenesis abundant proteins, abscisic acid (ABA) derivatives, chaperons, and certain dihydroflavonols, members of the phenylpropanoid pathway. MG-response of the two maize cultivars (A654 and Cm174) were somewhat different, but we recorded higher endogenous hydrogen peroxide (H2 O2 ) and lower nitric oxide (NO) level in at least one of the treated genotypes. These secondary signal molecules may provoke some of the changes in the hormonal, metabolic and gene expression profile. Decreased auxin transport, but increased ABA degradation and cytokinin and jasmonic acid (JA) synthesis, as well as an altered carbohydrate metabolism and transport (amylases, invertases, and SWEET transporters) could have promoted germination of MG-pretreated seeds. While LEA accumulation could have protected against osmotic stress and catalase expression and production of many antioxidants, like para-hydroxybenzoic acid (p-HBA) and anthocyanins may have balanced the oxidative environment for maize germination. Our results showed that MG-pretreatment could be an effective way to promote cold germination and its effect was more pronounced in the originally cold-sensitive maize genotype.
Assuntos
Germinação , Zea mays , Ácido Abscísico/metabolismo , Antocianinas/metabolismo , Aldeído Pirúvico/metabolismo , Aldeído Pirúvico/farmacologia , Sementes/genética , Temperatura , Zea mays/metabolismoRESUMO
Although light-emitting diode (LED) technology has extended the research on targeted photomorphogenic, physiological, and biochemical responses in plants, there is not enough direct information about how light affects polyamine metabolism. In this study, the effect of three spectral compositions (referred to by their most typical characteristic: blue, red, and the combination of blue and red [pink] lights) on polyamine metabolism was compared to those obtained under white light conditions at the same light intensity. Although light quality induced pronounced differences in plant morphology, pigment contents, and the expression of polyamine metabolism-related genes, endogenous polyamine levels did not differ substantially. When exogenous polyamines were applied, their roborative effect were detected under all light conditions, but these beneficial changes were correlated with an increase in polyamine content and polyamine metabolism-related gene expression only under blue light. The effect of the polyamines on leaf gene expression under red light was the opposite, with a decreasing tendency. Results suggest that light quality may optimize plant growth through the adjustment of polyamine metabolism at the gene expression level. Polyamine treatments induced different strategies in fine-tuning of polyamine metabolism, which were induced for optimal plant growth and development under different spectral compositions.
Assuntos
Poliaminas , Triticum , Folhas de Planta/metabolismo , Poliaminas/metabolismo , Putrescina/metabolismo , Espermidina/metabolismo , Espermina/metabolismo , Triticum/metabolismoRESUMO
Black tea leaves (Camellia sinensis) have been known for many years in lowering cholesterol level. The purpose of the present study was to find the effects of spent black tea leaves as a substitute of wheat bran on cholesterol reduction in broiler chicks. For this purpose a total of hundred & fifty (150), day old broiler poultry chicks were purchased from the local market. The spent black tea leaves were collected from tea stalls. Chicks were randomly distributed into 5 main groups according to spent black tea leaves and wheat bran supplementation. Group R0 was kept as control, containing 120 g/kg wheat bran but no spent black tea leaves supplementation; group R30 received spent black tea leaves supplemented feed at the rate of 30 g/kg plus 90 g/kg wheat bran; group R60 received spent black tea leaves supplemented feed at the rate of 60 g/kg plus 60 g/kg wheat bran, group R90 received spent black tea leaves supplemented feed at the rate of 90 g/kg plus 30 g/kg wheat bran and group R120 received the spent black tea leaves supplemented feed at the rate of 120 g/kg plus 0 g/kg wheat bran respectively. Each group was carrying three replicate (10 chicks/replicate). The data was statistically analyzed, using completely randomized design. Mean liver cholesterol per chick on diet R30, R60, R90, and R120 was 102.22, 93.55, 76.22, 60.78 and 51.55 mg/100 g. Breast cholesterol per chick on diet R30, R60, R90, and R120 was 61.89, 51.33, 44.78, 37 and 32.77 mg/100 g. It was concluded that the addition of spent black tea leaves at the rate of 120 g/kg has significant effect on cholesterol reduction and over all performance of broiler chicks and recommended that expensive wheat bran can be effectively replaced by these spent black tea leaves in broiler poultry ration.
Assuntos
Ração Animal , Galinhas/metabolismo , Colesterol/metabolismo , Fibras na Dieta/metabolismo , Suplementos Nutricionais , Fígado/metabolismo , Músculo Esquelético/metabolismo , Aves Domésticas/metabolismo , Chá/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , Biomarcadores/metabolismo , Galinhas/crescimento & desenvolvimento , Regulação para Baixo , Ingestão de Alimentos , Estado Nutricional , Folhas de Planta , Aves Domésticas/crescimento & desenvolvimento , Aumento de PesoRESUMO
The aim of this study was to evaluate the nutritional and feeding value of peanut hay (Arachis hypogaea L.) produced under tropical environment as an alternate forage resource for sheep. Peanut hay was appreciably high in crude protein [CP; 105 g/kg dry matter (DM)] and lower in neutral detergent fiber (NDF; 466 g/kg DM). Moreover, peanut hay was rich in Ca (12 g/kg DM) and P (1.7 g/kg DM). A feeding trial was conducted to investigate the effect of substituting wheat straw with peanut hay on nutrient intake, digestibility, and N utilization. Four adult Ramghani (Kaghani × Rambouillet) wethers (60 ± 2.5 kg body weight) were randomly assigned to the four dietary treatments according to a 4 × 4 Latin square design. The four rations were formulated on isonitrogenous and isocaloric bases and differed in the proportion (in grams per kilogram DM) of wheat straw/peanut hay, i.e., 700:0, 460:240, 240:460, and 0:700. The replacement of wheat straw with peanut hay increased the intakes of DM (P < 0.001), NDF (P < 0.01), and N (P < 0.001). Moreover, apparent in vivo digestibility of DM, NDF, and CP increased (P < 0.001) with the increasing proportion of peanut hay in the ration. Nitrogen retention in the body increased (P < 0.01; 3.2 to 8.1 g/day) with the replacement of wheat straw with peanut hay. These findings showed that substitution of wheat straw with peanut hay can improve DM and nutrients intake, digestibility, and N retention in sheep.
Assuntos
Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Arachis/química , Valor Nutritivo , Carneiro Doméstico/metabolismo , Animais , Dieta/veterinária , Proteínas Alimentares/metabolismo , Digestão/efeitos dos fármacos , Masculino , Nitrogênio/metabolismo , Distribuição Aleatória , Triticum/químicaRESUMO
The aim of the study was to reveal the influence of phyA mutations on polyamine metabolism in Arabidopsis under different spectral compositions. Polyamine metabolism was also provoked with exogenous spermine. The polyamine metabolism-related gene expression of the wild type and phyA plants responded similarly under white and far-red light conditions but not at blue light. Blue light influences rather the synthesis side, while far red had more pronounced effects on the catabolism and back-conversion of the polyamines. The observed changes under elevated far-red light were less dependent on PhyA than the blue light responses. The polyamine contents were similar under all light conditions in the two genotypes without spermine application, suggesting that a stable polyamine pool is important for normal plant growth conditions even under different spectral conditions. However, after spermine treatment, the blue regime had more similar effects on synthesis/catabolism and back-conversion to the white light than the far-red light conditions. The additive effects of differences observed on the synthesis, back-conversion and catabolism side of metabolism may be responsible for the similar putrescine content pattern under all light conditions, even in the presence of an excess of spermine. Our results demonstrated that both light spectrum and phyA mutation influence polyamine metabolism.
RESUMO
We investigated biochar-induced drought tolerance in Leptocohloa fusca (Kallar grass) by exploring the plant defense system at physiological level. L. fusca plants were exposed to drought stress (100%, 70%, and 30% field capacity), and biochar (BC), as an organic soil amendment was applied in two concentrations (15 and 30 mg kg-1 soil) to induce drought tolerance. Our results demonstrated that drought restricted the growth of L. fusca by inhibiting shoot and root (fresh and dry) weight, total chlorophyll content and photosynthetic rate. Under drought stress, the uptake of essential nutrients was also limited due to lower water supply, which ultimately affected metabolites including amino and organic acids, and soluble sugars. In addition, drought stress induced oxidative stress, which is evidenced by the higher production of reactive oxygen species (ROS) including hydrogen peroxide (H2O2), superoxide ion (O2-), hydroxyl ion (OH-), and malondialdehyde (MDA). The current study revealed that stress-induced oxidative injury is not a linear path, since the excessive production of lipid peroxidation led to the accumulation of methylglyoxal (MG), a member of reactive carbonyl species (RCS), which ultimately caused cell injury. As a consequence of oxidative-stress induction, the ascorbate-glutathione (AsA-GSH) pathway, followed by a series of reactions, was activated by the plants to reduce ROS-induced oxidative damage. Furthermore, biochar considerably improved plant growth and development by mediating metabolites and soil physio-chemical status.
RESUMO
Nanoparticles have numerous applications as drug carriers in drug delivery. The aim of the study was to produce tamoxifen nanoparticles with a defined size and higher encapsulation for efficient tissue uptake with controlled drug release. The quality by design approach was utilized to produce tamoxifen-loaded Eudragit nanoparticles by identifying the significant process variables using the nanoprecipitation method. The process variables (amount of drug, polymer, and surfactant) were altered to analyze the influence on particle size (PS), % encapsulation efficiency (EE). The results showed that the drug and polymer individually as well as collectively have an impact on PS, while the surfactant has no impact on the PS. The %EE was influenced by the surfactant individually and in interaction with the drug. The linear regression model was endorsed to fit the data showing high R2 values (PS, 0.9146, %EE, 0.9070) and low p values (PS, 0.0004, EE, 0.0005). The PS and EE were confirmed to be 178 nm and 90%, respectively. The nanoparticles were of spherical shape, as confirmed by SEM and TEM. The FTIR confirmed the absence of any incompatibility among the ingredients. The TGA confirmed that the NPs were thermally stable. The in vitro release predicted that the drug release followed Higuchi model.
RESUMO
Excessive use of nitrogen fertilizers enhanced the stem lodging, leading to serious threats to environmental sustainability. As the maize-soybean intercropping system is eco-friendly, however, soybean micro-climate hinders soybean growth and caused lodging. Since the relationship between nitrogen and lodging resistance under the intercropping system is not widely studied. Therefore, a pot experiment was conducted with the application of different nitrogen concentrations referring to low nitrogen (LN) = 0 mg/kg, optimum nitrogen (OpN) = 100 mg/kg, and high nitrogen (HN) = 300 mg/kg. To evaluate the optimum nitrogen fertilization under the maize-soybean intercropping system, two soybean cultivars were selected Tianlong 1 (TL-1), (lodging resistant) and Chuandou 16 (CD-16), (lodging susceptible). The results revealed that under the intercropping system, the OpN concentration significantly improved the lodging resistance of soybean cultivars by reducing the plant height of TL-1 and CD-16 by 4 and 28% as compared to LN, respectively. Following OpN, the lodging resistance index for CD-16 was also increased by 67% and 59% under the respective cropping systems. In addition, we found that OpN concentration prompted the lignin biosynthesis by stimulating the enzymatic activities of lignin biosynthetic enzymes (PAL, 4CL, CAD, and POD), which was reflected at the transcriptional levels (GmPAL, GmPOD, GmCAD, Gm4CL), too. Henceforth, we proposed that optimum nitrogen fertilization boosts soybean stem lodging resistance by modulating the lignin metabolism in the maize-soybean intercropping system.
Assuntos
Glycine max , Lignina , Lignina/metabolismo , Glycine max/metabolismo , Nitrogênio/metabolismo , Metabolismo Secundário , Zea mays/metabolismo , Agricultura/métodosRESUMO
The onset of pregnancy may be associated with hormonal changes and decline in milk yield of buffaloes. To investigate this, forty lactating buffaloes from 1st to 23rd weeks post-conception were selected. The animals were assigned to three treatments: PRT, PRS, NPRT and three milk yielding groups HMY, 66 to 75 l/week, n = 12; MMY, 56 to 65 l/week, n = 16; LMY, 46 to 55 l/week, n = 12). Milk samples were collected on alternate weeks and analyzed with ultrasonic milk analyzer. EIA was used for milk progesterone concentrations. Group means were compared and correlation analysis was conducted. Progesterone concentrations increased in almost similar pattern with the advancing weeks post-conception. The high and low yielder showed greater progesterone concentrations in the supplemented than the animals on traditional ration (P < 0.001). Progesterone concentrations correlated positively with fat (%), negatively with milk yield, protein (%) and lactose (%). Decline in milk yield became drastic when progesterone concentrations rose above 6.44 ng/ml. The pregnant animals on traditional ration exhibited a sharper decline in milk yield with the increasing progesterone concentrations as compared to pregnant animals with supplemented ration. It is concluded that concentrates supplementation induced a raise in progesterone levels. Progesterone concentrations and milk yield showed an inverse relationship.