Nitrogen fertilizers and the amount of vitamins in plants: A review

Effect of mineral fertilizers on the vitamin content of plants has received very little attention by scientists in English‐speaking countries, especially in recent years. A review of the literature, however, has revealed a rich source of information mostly published in non‐English journals. Based on these reports, nitrogen fertilizers, especially at high rates, seem to decrease the concentration of vitamin C in many different fruits and vegetables, among them potatoes, tomatoes and citrus fruits, the major sources of this vitamin in human nutrition in many societies. Nitrogen fertilizers are also shown to increase the concentrations of carotenes and vitamin B₁ in plants. Since excess use of nitrogen fertilizers increases the concentration of NO₃ in plant foods and simultaneously decreases that of ascorbic acid, a known inhibitor for the formation of carcinogenic N‐nitroso compounds from nitrite, it appears that the use of these fertilizers may have a double negative effect on the quality of food plants. Vitamin C and several carotenoids have antioxidant properties and reportedly reduce the risk of cardiovascular diseases and some forms of cancer. Whether long‐term consumption of food plants grown with excess use of nitrogen fertilizers would have an overall positive or negative effect on the total intake of antioxidative vitamins by consumers warrants investigation.     

Human Granulocyte Colony-Stimulating Factor (hG-CSF) Expression in Plastids of Lactuca sativa

Background: Human granulocyte colony-stimulating factor (hG-CSF) can serve as valuable biopharmaceutical for research and treatment of the human blood cancer. Transplastomic plants have been emerged as a new and high potential candidate for production of recombinant biopharmaceutical proteins in comparison with transgenic plants due to extremely high level expression, biosafety and many other advantages. Methods: hG-CSF gene was cloned into pCL vector between prrn16S promoter and TpsbA terminator. The recombinant vector was coated on nanogold particles and transformed to lettuce chloroplasts through biolistic method. Callogenesis and regeneration of cotyledonary explants were obtained by Murashige and Skoog media containing 6-benzylaminopurine and 1-naphthaleneacetic acid hormones. The presence of hG-CSF gene in plastome was studied with four specific PCR primers and expression by Western immunoblotting. Results: hG-CSF gene cloning was confirmed by digestion and sequencing. Transplastomic lettuce lines were regenerated and subjected to molecular analysis. The presence of hG-CSF in plastome was confirmed by PCR using specific primers designed from the plastid genome. Western immunoblotting of extracted protein from transplastomic plants showed a 20-kDa band, which verified the expression of recombinant protein in lettuce chloroplasts. Conclusions: This study is the first report that successfully express hG-CSF gene in lettuce chloroplast. The lettuce plastome can provide a cheap and safe expression platform for producing valuable biopharmaceuticals for research and treatment.Key Words: Plastid, Human granulocyte colony-stimulating factor (hG-CSF), Biolistics, Gene targeting     

Effect of dietary supplementation of whole flaxseed on sperm traits and sperm fatty acid profile in aged broiler breeder roosters

The objective of this study was to evaluate the effect of dietary supplementation of whole flaxseed on sperm traits and sperm fatty acid profile in aged broiler breeder roosters. Twelve Ross 308 broiler breeder roosters (age: 52 weeks; weight: 4,900 ± 210 g) haphazardly allotted to three dietary treatments (each treatment contained four replicates and one bird in each replicate) for six weeks. Treatments were different levels of flaxseed (0% flaxseed [GFL0], 2% flaxseed [GFL2] and 4% flaxseed [GFL4]). The feed intake quadratically decreased (p < .05) with increasing whole flaxseed levels for the period (58 to 60 weeks). Sperm traits (semen volume and sperm concentration, sperm total and forward motility, sperm viability and morphology, sperm plasma membrane functionality) were evaluated every two weeks (four times), and sperm fatty acid profile was assessed at the end of the experiment. Semen volume, sperm concentration and sperm morphology were not affected by treatments. On week 60, GFL2 group showed a significantly lower percentage of total and progressive sperm motility and sperm membrane functionality in comparison with the control and GFL4 groups. Also, sperm viability was lower in GFL2 group compared with other groups on week 58 (p < .05). In terms of sperm fatty acid profile, GFL2 group significantly reduced the percentage of linoleic acid (C18:2 [n-6]) in comparison with other groups. However, any of the other fatty acids were not affected by dietary flaxseed. In conclusion, dietary supplementation of whole flaxseed could not improve the quality of aged broiler breeder roosters' sperm in this study, nor it could alter the sperm fatty acid profile; thus, it seems necessary to use some antioxidants such as vitamin E in the diet of aged broiler breeder roosters, when supplementing the diets with oils or oilseeds such as flaxseed.     

Role of Silicon in Mediating Heat Shock Tolerance in Soybean

The present experiment was conducted to assess the role of silicon (Si; 0, 100, 200, and 300?mg L^?1 Na₂SiO₃) in mitigating heat stress-induced growth deficiency, photosynthesis inhibition, and oxidative damage in soybean cultivars. Heat stress lowered root and shoot dry weights, which were noticeably improved by Si supplementation. Exposition to 200?mg L^?1 Si caused a 45 and 34% increase in chlorophyll and Fv/Fm, respectively, compared to plants that received no Si. Net photosynthetic rate, intercellular CO₂, and stomatal conductance were lowered due to heat stress and Si supplementation mitigated the adverse effect of heat stress on these attributes. Furthermore, lipid peroxidation, hydrogen peroxide generation, and electrolyte leakage were higher in heat-stressed soybean cultivars without Si as compared to those supplemented with Si. Accumulation of osmolytic cytosolutes such as proline and glycine betaine was also boosted by Si supplementation. In addition, Si treatment alleviated the destructive effects of heat stress by 63, 64, and 50% increases in total phenol, flavonol, and tocopherol contents, respectively. Interestingly, including Si in the heat-stressed soybean cultivars improved protein content and enhanced the activities of catalase, phenylalanine ammonia lyase, and lipoxygenase, while the activities of superoxide dismutase, peroxidase, and polyphenol oxidase were lowered by 30, 56, and 54%, respectively, compared to non-Si-treated cultivars. In conclusion, Si alleviated the adverse effect of heat stress in soybean cultivars by modulating photosynthesis, further accumulating osmolytes, and regulating the antioxidant system. However, large-scale and long-term field trials must be carried out to investigate the economic feasibility of Si application for alleviating heat shock stress.

     

Differential inhibition of nitrification by three metabolic inhibitors

In a soil slurry the effects of two uncouplers of oxidative phosphorylation, DNP (2,4 dinitrophenol) and CCCP (carbonyl cyanide m‐chlorophenyl hydrazone), and one inhibitor of terminal oxidase (KCN) on biological oxidation (nitrification) of NH₄ ⁺ and NO₂ ^‐ to NO₃ ^‐ were studied. DNP did not affect, KCN reduced, and CCCP fully inhibited the oxidation of both NH₄ ⁺ and NO₂ ^‐ to NO₃ ^‐Addition of DNP to soil slurry resulted in formation of excess NO₃ ^‐ (over that of the control) which was stoichiometrically close to the amount of nitrogen in the added DNP. It is suggested that the ineffectiveness of DNP as nitrification inhibitor was partly due to its rapid hydrolysis and formation of excess NO₂ ^‐which was in turn nitrified to NO₃ ^‐ It is concluded that in comparison to DNP, CCCP and KCN introduce no artefacts into the experimental cultures and are thus better suited for studies involving inhibition of biological nitrification than DNP.     

Polymorphisms in the bovine HSP90AB1 gene are associated with heat tolerance in Thai indigenous cattle

Heat shock proteins act as molecular chaperones that have preferentially been transcribed in response to severe perturbations of the cellular homeostasis such as heat stress. Here the traits respiration rate (RR), rectal temperature (RT), pack cell volume (PCV) and the individual heat tolerance coefficient (HTC) were recorded as physiological responses on heat stress (environmental temperatures) in Bos taurus (crossbred Holstein Friesian; HF) and B. indicus (Thai native cattle: White Lamphun; WL and Mountain cattle; MT) animals (n = 47) in Thailand. Polymorphisms of the heat shock protein 90-kDa beta gene (HSP90AB1) were evaluated by comparative sequencing. Nine single nucleotide polymorphisms (SNP) were identified, i.e. three in exons 10 and 11, five in introns 8, 9, 10 and 11, and one in the 3′UTR. The exon 11 SNP g.5082C>T led to a missense mutation (alanine to valine). During the period of extreme heat (in the afternoon) RR and RT were elevated in each of the three breeds, whereas the PCV decreased. Mountain cattle and White Lamphun heifers recorded significantly better physiologic parameters (p < 0.05) in all traits considered, including or particularly HTC than Holstein Friesian heifers. The association analysis revealed that the T allele at SNP g.4338T>C within intron 3 improved the heat tolerance (p < 0.05). Allele T was exclusively found in White Lamphun animals and to 84% in Mountain cattle. Holstein Friesian heifers revealed an allele frequency of only 18%. Polymorphisms within HSP90AB1 were not causative for the physiological responses; however, we propose that they should at least be used as genetic markers to select appropriate breeds for hot climates.     

SNP g.1007A>G within the porcine DNAL4 gene affects sperm motility traits and percentage of midpiece abnormalities

The flagellar beating of a spermatozoa's axoneme is caused by the varying activation and inactivation of dynein molecules. Dynein, axonemal, light chain 4 (DNAL 4 ) is a functional candidate gene for sperm motility as it encodes a small subunit of the dyneins. We resequenced the porcine DNAL 4 using three artificial insemination (AI ) boars each with high (>68%) or low (<60%) motility, and detected 23 SNP . These were then genotyped for 82 AI boars. Using spermatological records, significantly negative genetic correlations between ejaculate volume (VOL ) and the further spermatological parameters concentration (CONC ) (r  = ?.43), motility of undiluted semen (MOTUD ) (r  = ?.09), motility after 24 h (MOT 1) (r  = ?.17) and after 48 hr (MOT 2) (r  = ?.23) were estimated. Significantly positive correlations existed between CONC and MOT 1 (r  = .07) as well as MOT 2 (r  = .10), between MOTUD and MOT 1 (r  = .33), between MOTUD and MOT 2 (r  = .36), and finally between MOT 1 and MOT 2 (r  = .70). Significantly negatively correlated were all motility traits with the parameters abnormal acrosome (AA ) (MOTUD r  = ?.06; MOT 1 r  = ?.08, and MOT 2 r  = ?.1) and presence of cytoplasmic droplet (CD ) (MOTUD r  = ?.07; MOT 1 r  = ?.08; MOT 2 r  = ?.07). Association analyses (single marker regression model; SMR ) propose that SNP g.1007A>G, located in the second intron, reduces motility significantly (MOTUD ‐4.59%; MOT 1 ‐10.33%; MOT 2 ‐19.37%). According to the dominant‐recessive model (DRM ), genotype AA is always superior compared to genotypes AG and GG (i.e. MOTUD 67.67%, 64.16% and 53.91%; MOT 1 54.17%, 43.75% and 28.44%; MOT 2 44.12%, 24.91% and 4.97%). The average effect of gene substitution (g.1007A>G) on abnormal midpiece (AM ) was 0.71%, the genotypic values—as expressed by LS means—were 0.1 (AA ) and 0.81 (AG ).     

The effect of grapeseed oil on performance,rumen fermentation,antioxidant status and subcutaneous adipose fatty acid profile in lambs

This experiment was carried out to examine the effect of grapeseed oil (GSO) on performance, rumen fermentation, antioxidant status and subcutaneous adipose fatty acid (FA) profile in lambs. Eighteen Baluchi lambs, 196 ± 14 days of age and 39.8 ± 1.7 kg body weight, were randomly assigned to three experimental diets: (i) diet without GSO (control), (ii) diet containing 2% of GSO (GSO2) and (iii) diet containing 4% of GSO (GSO4) for 42 days. Results showed that the experimental diets had no significant effect on dry matter intake and performance (p > 0.05). The supplemented diets with GSO had no effect on pH and NH₃‐N of rumen fluid (p > 0.05), but GSO4 increased (p = 0.003) the concentration of propionic acid and reduced (p = 0.002) the concentration of acetate acid compared to the control. Inclusion 4% of GSO to the diet increased total antioxidant activity and decreased malondialdehyde in serum and muscle (p < 0.001). The level of blood glutathione peroxidase in diets containing GSO was higher than control diet (p = 0.02), but diets had no effect on superoxide dismutase in blood and muscle tissues (p > 0.05). The concentration of vaccenic acid, rumenic acid and linoleic acid and thus polyunsaturated fatty acid in subcutaneous fat was affected by experimental diets (p < 0.001), as control had the lowest amount of these FAs and GSO4 had the highest amount of them. Therefore, it can be concluded that the use of GSO up to 4% improves the antioxidant status and adipose fatty acid profile in lambs without effects on performance.     

Breeding for low body weight in Goettingen minipigs.

The Goettingen minipig is a laboratory animal with increasing popularity in medical research. To get a genetically smaller minipig, a new breeding scheme with a focus on weight reduction has to be developed. Therefore, 19 505 body weight measurements of 3461 Goettingen minipigs were analysed with multiple trait models and random regression models (RRM) for the estimation of genetic parameters. Heritabilities were moderate with slightly higher values estimated with the RRM. Genetic correlations between body weight measurements at different ages were decreasing with increasing time lag between the measurements. An operational breeding goal for relative weight reduction RWR is suggested in which the weight reduction in each age class is expressed as per cent of the actual body weight and is weighted according to the proportion of animals sold in this age class. Expected genetic progress was calculated for two different selection ages (80 and 150 days). Selection at age 150 days leads to an expected genetic progress of 3.9 % RWR per year. And it is shown how the selection for RWR will modify the shape of the growth curve. On the basis of these results, a new breeding scheme with a focus on weight reduction can be implemented, which also has to account for correlated undesirable effects, like decline of fertility and increased rate of inbreeding.