Root zone selenium reduces cadmium toxicity by modulating tissue-specific growth and metabolism in maize (Zea mays L.)

The effects of selenium (Se) cadmium (Cd) interactions on plant growth and metabolism are not fully clear. In the present study, we assessed whether Se could alleviate the toxic effects of Cd on growth and metabolism of maize. Seeds of maize variety FH-985 were sown in pots filled with sand treated with CdCl₂ (0, 50 and 100 µM) and Se (0, 2 and 4 mg L^?1) through Hoagland’s nutrient solution. Low Se (2 mg L^?1) increased germination percentage and rate, while high Se (4 mg L^?1) increased fresh and dry biomass under Cd stress. Interestingly, all Se concentrations were effective in alleviating the toxic effects of Cd on photosynthetic pigments, whereas higher Se mitigated the Cd-induced oxidative stress and increased flavonoids both in the shoots and roots while phenolics in the roots. The results demonstrated that root zone Se altered tissue-specific primary metabolism in maize. Furthermore, low Se mitigated the Cd-induced decrease in total proteins in the root. Overall, Se-mediated decrease in the oxidative stress in the shoots while increase of secondary metabolites in the roots helped the plants to grow faster at early growth stage and caused increase in the biomass under different Cd regimes.     

Determination of annual reproductive cycle in male sterlet,Acipenser ruthenus using histology and ultrasound imaging

Fish Physiology and Biochemistry - The aim of this study was to evaluate seasonal testicular development in the cultured sterlet, Acipenser ruthenus. During annual sexual cycle of male sterlet,...     

Novel technique for definite blastomere inhibition and distribution of maternal RNA in sterlet Acipenser ruthenus embryo

Fisheries Science - The cleavage pattern of a vertebrate’s embryo is either holoblastic (complete) or meroblastic (partial). Sturgeon and other basal bony fishes represent a transition of the...     

Behaviour and reproductive performance of Nigerian native chickens subjected to different mating ratios for a short term

To date, there is no reported standard mating ratio for Nigerian native chickens despite their large population in the country. This study investigated the effect of mating ratio on behaviour, semen quality and level of stress. Sixty-three (9 cocks and 54 hens) sexually matured birds were randomly assigned to three mating ratios (MR) of 1 cock to 3 hens (1C:3H), 1 cock to 6 hens (1C:6H) and 1 cock to 9 hens (1C:9H), and each MR was replicated three times. Each cock spent 2 weeks in a particular MR before it was moved to another. By the 6th week, all cocks had experienced the three mating ratios. Behaviour of the hens and sexual behaviour of the cocks were observed in the morning and evening, respectively, for 6 weeks. At the end of 2nd week in each MR, semen samples were collected and evaluated for motility, morphology, liveability and concentration, and blood samples were also taken from the cocks to determine the heterophil/lymphocyte (H:L) ratio, an indicator of stress. There was also no significant effect of mating ratio on the fertility of eggs and hatchability of the chicks. The number of hen–hen aggression instances, frequency of visits to the nest box and duration of nesting was not influenced by the mating ratio. However, the duration of nest seeking was higher at 1C:3H and lower at 1C:9H. A mating ratio of 1C:9H is therefore recommended for farmers interested in raising Nigerian native chickens.     

Field appraisal of herbicide potential of sunflower leaf extract against Rumex dentatus

Comparative evaluation of sunflower aqueous extracts and commercially available synthetic herbicides was carried out in field trials. Crude aqueous extract was tested in 80 and 100% concentrations in plots where wheat was grown with Rumex dentatus in a 1:1 mix. In comparison with the synthetic herbicides (Buctril-Super^® and Chwastox^®) the aqueous extract failed to kill 100% of selected weeds, but the highest tested extract concentration completely overcame weed crop competition by reducing the weed biomass and increasing wheat yield significantly. The trial confirmed the herbicidal potential of sunflower allelochemicals against broad leaf weeds.     

Wheat Gluten Polymer Structures: The Impact of Genotype,Environment, and Processing on Their Functionality in Various Applications

For a number of applications, gluten protein polymer structures are of the highest importance in determining end‐use properties. The present article focuses on gluten protein structures in the wheat grain, genotype‐ and environment‐related changes, protein structures in various applications, and their impact on quality. Protein structures in mature wheat grain or flour are strongly related to end‐use properties, although influenced by genetic and environment interactions. Nitrogen availability during wheat development and genetically determined plant development rhythm are the most important parameters determining the gluten protein polymer structure, although temperature during plant development interacts with the impact of the mentioned parameters. Glutenin subunits are the main proteins incorporated in the gluten protein polymer in extracted wheat flour. During dough mixing, gliadins are also incorporated through disulfide‐sulfhydryl exchange reactions. Gluten protein polymer size and complexity in the mature grain and changes during dough formation are important for breadmaking quality. When using the gluten proteins to produce plastics, additional proteins are incorporated in the polymer through disulfide‐sulfhydryl exchange, sulfhydryl oxidation, β‐eliminations with lanthionine formation, and isopeptide formation. In promising materials, the protein polymer structure is changed toward β‐sheet structures of both intermolecular and extended type and a hexagonal close‐packed structure is found. Increased understanding of gluten protein polymer structures is extremely important to improve functionality and end‐use quality of wheat‐ and gluten‐based products.     

The removal of nitrate reductase phosphorylation enhances tolerance to ammonium nitrogen deficiency in rice

Nitrate reductase (NR) is a key enzyme for nitrogen assimilation in plants, and its activity is regulated by posttranslational phosphorylation. To investigate the effects of dephosphorylation of the NIA1 protein on the growth and the physiological and biochemical characteristics of rice under different forms of nitrogen supplies, the phenotypes, nitrogen metabolism and reactive oxygen metabolism were measured in NIA1 phosphorylation site-directed mutant lines (S532D and S532A), an OsNia1 over-expression line (OE) and Kitaake (wild type, WT). Compared with WT and OE, S532D and S532A have stronger nitrogen assimilation capacities. When ammonium nitrate served as the nitrogen source, the plant heights, dry weights of shoots and chlorophyll (Chl) contents of S532D and S532A were lower than those of the WT and OE, whereas hydrogen peroxide (H₂O₂), malondialdehyde (MDA) and nitrite contents were higher. When potassium nitrate served as the nitrogen source, the plant heights, dry weights of shoots and Chl contents of S532D and S532A were higher than those of the WT and OE, there were no significant differences in the contents of H₂O₂ and MDA in the leaves of the test materials, and the difference in nitrite contents among different lines decreased. When ammonium sulfate served as the nitrogen source, there were no significant differences in the physiological indexes of the test materials, except NR activity. Compared with ammonium nitrate and ammonium sulfate, the content of NH₄⁺-N in the leaves of each plant was lower when potassium nitrate was used as the nitrogen source. The qPCR results showed that OsGS and OsNGS1 were negatively regulated by downstream metabolites, and OsNrt2.2 was induced by nitrate. In summary, when ammonium nitrate served as the nitrogen source, the weak growth of NIA1 phosphorylation site-directed mutant lines was due to the toxicity caused by the excessive accumulation of nitrite. When potassium nitrate served as the nitrogen source, the assimilation rates of nitrate, nitrite and ammonium salt were accelerated in NIA1 phosphorylation site-directed mutant lines, which could provide more nitrogen nutrition and improve the tolerance of rice to ammonium nitrogen deficiency. These results could provide a possible method to improve the efficiency of nitrogen utilization in rice under low-nitrogen conditions.     

Altered telomeres in tumors with ATRX and DAXX mutations

The proteins encoded by ATRX and DAXX participate in chromatin remodeling at telomeres and other genomic sites. Because inactivating mutations of these genes are common in human pancreatic neuroendocrine tumors (PanNETs), we examined the telomere status of these tumors. We found that 61% of PanNETs displayed abnormal telomeres that are characteristic of a telomerase-independent telomere maintenance mechanism termed ALT (alternative lengthening of telomeres). All of the PanNETs exhibiting these abnormal telomeres had ATRX or DAXX mutations or loss of nuclear ATRX or DAXX protein. ATRX mutations also correlate with abnormal telomeres in tumors of the central nervous system. These data suggest that an alternative telomere maintenance function may operate in human tumors with alterations in the ATRX or DAXX genes.     

The Expression of Epidermal Growth Factor (EGF) and its Receptor (EGFR) During Post‐Natal Testes Development in the Yak

Growth factors play critical role in cell proliferation, regulate tissue differentiation and modulate organogenesis. Several growth factors have been identified in the testes of various mammalian species in last few years. In present investigation, the objective was to determine the expression of epidermal growth factor (EGF) and the epidermal growth factor receptor (EGFR) in yak testicular tissue by relative quantitative real time polymerase chain reaction (RT‐PCR), Western blot (WB) and immunohistochemistry (IHC) from mRNA and protein levels. The testicular tissues were collected from male yak at 6 and 24 months old. Results of RT‐PCR and WB showed that the expression quantity of EGF and EGFR at 24 months of age was higher than at 6 months, and the increase rate of EGFR on mRNA and protein levels was higher than the increase rate EGF during post‐natal testes development. Positive staining for EGF and EGFR was very low and mainly localized to Leydig cells testes at 6 months of age with immunohistochemistry, and seminiferous tubules were not observed. At 24 month of age, both the EGF and EGFR could be detected in Leydig cells, peritubular myoid cells, sertoli cells and germ cells of the yak testes. However, EGF and EGFR were localized to preferential adluminal compartment and basal compartment in the seminiferous tubules, respectively. In conclusion, the findings in present studies suggest that EGF and EGFR as important paracrine and/or autocrine regulators in yak testes development and spermatogenesis.