Evaluation of two concepts of fertilization for wheat in a calcareous soil of Bangladesh

Two popular concepts of soil fertilization, basic cation saturation ratio (BCSR) and sufficiency level of available nutrients (SLAN), were tested on a calcareous soil (Aeric haplaquept) during 1995-1996 at the Bangladesh Rice Research Institute (BRRI) Regional Station Rajshahi using wheat as a test crop. According to BCSR concept the soil was deficient in potassium (K) and according to SLAN concept it was deficient in phosphorus (P), respectively. Potassium dose of 120 kg ha-1 [to attain 2% saturation of total cation exchange capacity (CEC) according to BCSR] along with other two doses (0 and 60 kg K ha-1) and P dose of 50 kg ha-1 (to attain available P at sufficiency level) along with other two doses (0 and 100 kg P ha-1) were compared in a randomized complete block design. The application of 50 kg P ha-1 significantly increased plant height, spikes m-2, grains per spike, grain and straw yields of wheat over 0 kg P ha-1 with or without K but increasing P dose from 50 to 100 kg P ha-1 did not give additional yields. The agronomic parameters and yields were not affected significantly by K application. Similar results were also observed in nutrient content and nutrient uptake. Thus, SLAN concept appeared as an effective tool for fertilizer recommendation for the calcareous soil while BCSR gave no apparent result there

Yield and phosphorus efficiency of some lowland rice varieties at different levels of soil‐available phosphorus

A field experiment was conducted on an Aeric Haplaquept soil to study the effect of phosphorus (P) deficiency in soil on the P nutrition and yield of five modern varieties of rice, viz., Purbachi, BR1, BR3, BR14, and BR29, popular with the rice farmers of Bangladesh. Soil-available P in the different plots of the experimental field varied widely, from 2.8 to 16.4 ppm. This plot to plot variation in soil-available P content resulted from differences in the total amounts (0 to 480 kg ha -1) of P the plots had received over a period of 8 years in a long-term P fertilizer trial conducted previously in the same field. Phosphorus deficiency in soil drastically reduced the grain yield of all the rice varieties. In severely P deficient plots, where soil-available P was around 3 ppm, the yield was less than 1 ton ha -1 while in plots containing an adequate P level, i.e., >6 ppm, the yield was more than 4 t ha -1. Rice yield increased linearly with an increase in soil P content up to 6 ppm, and the highest grain yield for any variety, obtained at 6-7 ppm of soil-available P leveled off at this point. Soil P deficiency not only decreased rice yield severely but also decreased P content in straw and grain drastically. However, differences among rice varieties were noted in P nutrition, particularly at low soil P levels. The rice varieties differed markedly also in respect of internal P efficiency. The BR29 showed the highest internal P efficiency both at low and high soil P levels. In all the rice varieties, internal P efficiency decreased with an increase in soil P levels

Position and sequence conservation in Amniota of polymorphic enhancer HS1.2 within the palindrome of IgH 3'Regulatory Region

<p>Abstract</p> <p>Background</p> <p>The Immunoglobulin heavy chain (IgH) 3' Regulatory Region (3'RR), located at the 3' of the constant alpha gene, plays a crucial role in immunoglobulin production. In humans, there are 2 copies of the 3'RR, each composed of 4 main elements: 3 enhancers and a 20 bp tandem repeat. The single mouse 3'RR differs from the two human ones for the presence of 4 more regulative elements with the double copy of one enhancer at the border of a palindromic region.</p> <p>Results</p> <p>We compared the 3'RR organization in genomes of vertebrates to depict the evolutionary history of the region and highlight its shared features. We found that in the 8 species in which the whole region was included in a fully assembled contig (mouse, rat, dog, rabbit, panda, orangutan, chimpanzee, and human), the shared elements showed synteny and a highly conserved sequence, thus suggesting a strong evolutionary constraint. In these species, the wide 3'RR (~30 kb in human) bears a large palindromic sequence, consisting in two ~3 kb complementary branches spaced by a ~3 kb sequence always including the HS1.2 enhancer. In mouse and rat, HS3 is involved by the palindrome so that one copy of the enhancer is present on each side. A second relevant feature of our present work concerns human polymorphism of the HS1.2 enhancer, associated to immune diseases in our species. We detected a similar polymorphism in all the studied Catarrhini (a primate parvorder). The polymorphism consists of multiple copies of a 40 bp element up to 12 in chimpanzees, 8 in baboons, 6 in macaque, 5 in gibbons, 4 in humans and orangutan, separated by stretches of Cytosine. We show specific binding of this element to nuclear factors.</p> <p>Conclusions</p> <p>The nucleotide sequence of the palindrome is not conserved among evolutionary distant species, suggesting pressures for the maintenance of two self-matching regions driving a three-dimensional structure despite of the inter-specific divergence at sequence level. The information about the conservation of the palindromic structure and the settling in primates of the polymorphic feature of HS1.2 show the relevance of these structures in the control and modulation of the Ig production through the formation of possible three-dimensional structures.</p

Transient receptor potential canonical 5 (TRPC5) protects against pain and vascular inflammation in arthritis and joint inflammation

Objective: Transient receptor potential canonical 5 (TRPC5) is functionally expressed on a range of cells including fibroblast-like synoviocytes, which play an important role in arthritis. A role for TRPC5 in inflammation has not been previously shown in vivo. We investigated the contribution of TRPC5 in arthritis. Methods: Male wild-type and TRPC5 knockout (KO) mice were used in a complete Freund’s adjuvant (CFA)-induced unilateral arthritis model, assessed over 14 days. Arthritis was determined by measurement of knee joint diameter, hindlimb weightbearing asymmetry and pain behaviour. Separate studies involved chronic pharmacological antagonism of TRPC5 channels. Synovium from human post-mortem control and inflammatory arthritis samples were investigated for TRPC5 gene expression. Results: At baseline, no differences were observed. CFA-induced arthritis resulted in increased synovitis in TRPC5 KO mice assessed by histology. Additionally, TRPC5 KO mice demonstrated reduced ipsilateral weightbearing and nociceptive thresholds (thermal and mechanical) following CFA-induced arthritis. This was associated with increased mRNA expression of inflammatory mediators in the ipsilateral synovium and increased concentration of cytokines in synovial lavage fluid. Chronic treatment with ML204, a TRPC5 antagonist, augmented weightbearing asymmetry, secondary hyperalgesia and cytokine concentrations in the synovial lavage fluid. Synovia from human inflammatory arthritis demonstrated a reduction in TRPC5 mRNA expression. Conclusions: Genetic deletion or pharmacological blockade of TRPC5 results in an enhancement in joint inflammation and hyperalgesia. Our results suggest that activation of TRPC5 may be associated with an endogenous anti-inflammatory/analgesic pathway in inflammatory joint conditions

GFI1 proteins regulate stem cell formation in the AGM

In vertebrates, the first haematopoietic stem cells (HSCs) with multi-lineage and long-term repopulating potential arise in the AGM (aorta-gonad-mesonephros) region. These HSCs are generated from a rare and transient subset of endothelial cells, called haemogenic endothelium (HE), through an endothelial-to-haematopoietic transition (EHT). Here, we establish the absolute requirement of the transcriptional repressors GFI1 and GFI1B (growth factor independence 1 and 1B) in this unique trans-differentiation process. We first demonstrate that Gfi1 expression specifically defines the rare population of HE that generates emerging HSCs. We further establish that in the absence of GFI1 proteins, HSCs and haematopoietic progenitor cells are not produced in the AGM, revealing the critical requirement for GFI1 proteins in intra-embryonic EHT. Finally, we demonstrate that GFI1 proteins recruit the chromatin-modifying protein LSD1, a member of the CoREST repressive complex, to epigenetically silence the endothelial program in HE and allow the emergence of blood cells.We thank the staff at the Advanced Imaging, animal facility, Molecular Biology Core facilities and Flow Cytometry of CRUK Manchester Institute for technical support and Michael Lie-A-Ling and Elli Marinopoulou for initiating the DamID-PIP bioinformatics project. We thank members of the Stem Cell Biology group, the Stem Cell Haematopoiesis groups and Martin Gering for valuable advice and critical reading of the manuscript. Work in our laboratory is supported by the Leukaemia and Lymphoma Research Foundation (LLR), Cancer Research UK (CRUK) and the Biotechnology and Biological Sciences Research Council (BBSRC). SC is the recipient of an MRC senior fellowship (MR/J009202/1).This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/ncb327

A Large Gene Network in Immature Erythroid Cells Is Controlled by the Myeloid and B Cell Transcriptional Regulator PU.1

PU.1 is a hematopoietic transcription factor that is required for the development of myeloid and B cells. PU.1 is also expressed in erythroid progenitors, where it blocks erythroid differentiation by binding to and inhibiting the main erythroid promoting factor, GATA-1. However, other mechanisms by which PU.1 affects the fate of erythroid progenitors have not been thoroughly explored. Here, we used ChIP-Seq analysis for PU.1 and gene expression profiling in erythroid cells to show that PU.1 regulates an extensive network of genes that constitute major pathways for controlling growth and survival of immature erythroid cells. By analyzing fetal liver erythroid progenitors from mice with low PU.1 expression, we also show that the earliest erythroid committed cells are dramatically reduced in vivo. Furthermore, we find that PU.1 also regulates many of the same genes and pathways in other blood cells, leading us to propose that PU.1 is a multifaceted factor with overlapping, as well as distinct, functions in several hematopoietic lineages

Quantity-to-intensity (Q/I) relationships can efficiently characterize intensively cultivated agricultural soils in Bangladesh for better potassium supplying capacity

Aim of the study: Firstly, to evaluate the K dynamics of soils through a quantity-intensity isotherm study; and secondly, to characterize the soils on the basis of quantity-intensity (Q/I) parameters. Area of study: Gazipur, Bangladesh Material and methods: Eleven soils collected from major agro-ecological zones in Bangladesh were evaluated for their varying K dynamics parameters, and K supplying capacities of these soils were described. Main results: The Q/I plot showed both linear and polynomial relationships for soils in the study. The eleven soils had labile K ranging from 0.022 in Palashbari clay loam to 1.35 cmol kg-1 in Barisal clay. The latter soil had the highest equilibrium K activity ratio (0.003 mol L-1)1/2 and potential buffering capacity (PBC) (460.4 (cmol kg-1) (mol L-1)1/2). The PBC of soils for non-exchangeable pool (PBCne) was much higher than that of exchangeable pool (PBCe) in most soils. The largest amount of PBCne and PBCe occurred in Barisal clay, Gopalpur clay, Jhalokathi clay and Nachol loam which had a higher K desorption rate than all the other soils. The equilibrium exchangeable K, critical exchangeable K and equilibrium solution K of the soils varied widely (0.0006-0.035, 0.06-0.61 and 0.06-0.604 cmol kg-1, respectively). The added K was converted almost equally for the respective soils, with specific reference to the respective exchangeable and non-exchangeable pool for Barisal clay and Nachol loam. Research highlights: All the studied parameters revealed wide variations among the soils. The linear and polynomial relationships for soils can efficiently characterize intensively cultivated soils in Bangladesh