Mapping Variability of Soybean Leaf Potassium Concentrations to Develop a Sampling Protocol

The spatial variability of soybean [Glycine max (L.) Merr.] leaf-K (potassium) concentrations must be considered when collecting samples to monitor crop K status. Five commercial soybean fields were sampled at a 0.4-ha grid resolution at two reproductive growth stages to quantify the trifoliolate tissue-K concentration. The objectives of this study were to identify the potential field variability of soybean leaf-K concentrations in typical Mid-south US soybean production fields, evaluate interpolation methods, and develop a sampling protocol for in-season soybean tissue monitoring. No consistent spatial dependencies were found in the leaf-K concentrations across the fields and sample times, indicating that a soybean tissue-K grid sampling protocol cannot be generalized to a specific area size. Inverse distance weighted (IDW) and rasterization interpolation methods were considered to predict leaf-K concentrations between the sampled grid points at grid resolutions ranging from 0.4 to 4 ha. The IDW method consistently predicted leaf-K concentrations between the known values with less error than rasterization. Rather than grid sampling, composite leaf samples should be collected based on management zones to provide a simplified sampling protocol. Within each management zone, a composite sample must consist of uppermost fully expanded trifoliolate leaves collected from at least 18 locations to ensure that the sample measures within the 95% confidence interval of the area average leaf-K concentration. The developed sampling protocol coupled with the dynamic critical tissue-K concentration curve will provide producers with the ability to effectively monitor soybean for potential hidden hunger and verify K deficiency symptoms in season

Development and bin mapping of gene-associated interspecific SNPs for cotton (Gossypium hirsutum L.) introgression breeding efforts

BACKGROUND: Cotton (Gossypium spp.) is the largest producer of natural fibers for textile and is an important crop worldwide. Crop production is comprised primarily of G. hirsutum L., an allotetraploid. However, elite cultivars express very small amounts of variation due to the species monophyletic origin, domestication and further bottlenecks due to selection. Conversely, wild cotton species harbor extensive genetic diversity of prospective utility to improve many beneficial agronomic traits, fiber characteristics, and resistance to disease and drought. Introgression of traits from wild species can provide a natural way to incorporate advantageous traits through breeding to generate higher-producing cotton cultivars and more sustainable production systems. Interspecific introgression efforts by conventional methods are very time-consuming and costly, but can be expedited using marker-assisted selection. RESULTS: Using transcriptome sequencing we have developed the first gene-associated single nucleotide polymorphism (SNP) markers for wild cotton species G. tomentosum, G. mustelinum, G. armourianum and G. longicalyx. Markers were also developed for a secondary cultivated species G. barbadense cv. 3–79. A total of 62,832 non-redundant SNP markers were developed from the five wild species which can be utilized for interspecific germplasm introgression into cultivated G. hirsutum and are directly associated with genes. Over 500 of the G. barbadense markers have been validated by whole-genome radiation hybrid mapping. Overall 1,060 SNPs from the five different species have been screened and shown to produce acceptable genotyping assays. CONCLUSIONS: This large set of 62,832 SNPs relative to cultivated G. hirsutum will allow for the first high-density mapping of genes from five wild species that affect traits of interest, including beneficial agronomic and fiber characteristics. Upon mapping, the markers can be utilized for marker-assisted introgression of new germplasm into cultivated cotton and in subsequent breeding of agronomically adapted types, including cultivar development. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-945) contains supplementary material, which is available to authorized users

Non-destructive high-throughput DNA extraction and genotyping methods for cotton seeds and seedlings

Extensive use of targeted PCR-based genotyping is precluded for many plant research laboratories by the cost and time required for DNA extraction. Using cotton (Gossypium hirsutum) as a model for plants with medium-sized seeds, we report here manual procedures for inexpensive non-destructive high-throughput extraction of DNA suitable for PCR-based genotyping of large numbers of individual seeds and seedlings. By sampling only small amounts of cotyledon tissue of ungerminated seed or young seedlings, damage is minimized, and viability is not discernibly affected. The yield of DNA from each seed or seedling is typically sufficient for 1000 or 500 PCR reactions, respectively. For seeds, the tissue sampling procedure relies on a modified 96-well plate that is used subsequently for seed storage. For seeds and seedlings, the DNA is extracted in a strongly basic DNA buffer that is later neutralized and diluted. Extracts can be used directly for high-throughput PCR-based genotyping. Any laboratory can thus extract DNA from thousands of individual seeds/seedlings per person-day at a very modest cost for consumables (∼$0.05 per sample). Being non-destructive, our approach enables a wide variety of time- and resource-saving applications, such as marker-assisted selection (MAS), before planting, transplanting, and flowering

Chemotherapy induced intestinal mucosal barrier damage: a cause of falsely elevated serum 1.3-beta-d-glucan levels?

Blood citrulline and intestinal fatty acid binding protein were determined as biomarkers for intestinal mucositis. Biomarker levels were correlated with corresponding serum 1,3-beta-d-glucan levels in 56 samples obtained from 33 cases with underlying hematological malignancies receiving induction chemotherapy. No correlation between biomarkers of intestinal mucositis and BDG levels was observed.status: publishe

Highly Efficient Genome Editing of Murine and Human Hematopoietic Progenitor Cells by CRISPR/Cas9

Our understanding of the mechanisms that regulate hematopoietic stem/progenitor cells (HSPCs) has been advanced by the ability to genetically manipulate mice; however, germline modification is time consuming and expensive. Here, we describe fast, efficient, and cost-effective methods to directly modify the genomes of mouse and human HSPCs using the CRISPR/Cas9 system. Using plasmid and virus-free delivery of guide RNAs alone into Cas9-expressing HSPCs or Cas9-guide RNA ribonucleoprotein (RNP) complexes into wild-type cells, we have achieved extremely efficient gene disruption in primary HSPCs from mouse (>60%) and human (∼75%). These techniques enabled rapid evaluation of the functional effects of gene loss of Eed, Suz12, and DNMT3A. We also achieved homology-directed repair in primary human HSPCs (>20%). These methods will significantly expand applications for CRISPR/Cas9 technologies for studying normal and malignant hematopoiesis

Highly Efficient Genome Editing of Murine and Human Hematopoietic Progenitor Cells by CRISPR/Cas9

Summary: Our understanding of the mechanisms that regulate hematopoietic stem/progenitor cells (HSPCs) has been advanced by the ability to genetically manipulate mice; however, germline modification is time consuming and expensive. Here, we describe fast, efficient, and cost-effective methods to directly modify the genomes of mouse and human HSPCs using the CRISPR/Cas9 system. Using plasmid and virus-free delivery of guide RNAs alone into Cas9-expressing HSPCs or Cas9-guide RNA ribonucleoprotein (RNP) complexes into wild-type cells, we have achieved extremely efficient gene disruption in primary HSPCs from mouse (>60%) and human (∼75%). These techniques enabled rapid evaluation of the functional effects of gene loss of Eed, Suz12, and DNMT3A. We also achieved homology-directed repair in primary human HSPCs (>20%). These methods will significantly expand applications for CRISPR/Cas9 technologies for studying normal and malignant hematopoiesis. : Gundry et al. develop an efficient and simple method implementing CRISPR/Cas9-mediated gene disruption and HDR in murine and human HSPCs. This method enables quick evaluation of the function of genes by performing in vitro or transplantation assays using the modified HSPCs. Keywords: HSC, hematopoietic stem cells, progenitor, human CD34, genome editing, CRISPR/Cas9, sgRNA, homology-directed repair, gene therapy, transplantatio

Donated stool for faecal microbiota transplantation is not a drug, but guidance and regulation are needed

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Stool for fecal microbiota transplantation should be classified as a transplant product and not as a drug

Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc