- Saskatoon, Saskatchewan, Canada
Lester Young
University of Saskatchewan, Plant sciences, Department Member
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Objective The brown seed coat colour of flax (Linum ustiatissimum) results from proanthocyanidin synthesis and accumulation. Glutathione S-transferases (GSTs), such as the TT19 protein in Arabidopsis, have been implicated in the transport... more
Objective The brown seed coat colour of flax (Linum ustiatissimum) results from proanthocyanidin synthesis and accumulation. Glutathione S-transferases (GSTs), such as the TT19 protein in Arabidopsis, have been implicated in the transport of anthocyanidins during the synthesis of the brown proanthocyanidins. This study fine mapped the g allele responsible for yellow seed colour in S95407 and identified it as a putative mutated GST. Results We developed a Recombinant Inbred Line population with 320 lines descended from a cross between CDC Bethune (brown seed coat) and S95407 (yellow seed) and used molecular markers to fine map the G gene on Chromosome 6 (Chr 6). We used Next Generation Sequencing (NGS) to identify a putative GST was identified in this region and Sanger sequenced the gene from CDC Bethune, S95407 and other yellow seeded genotypes. The putative GST from S95407 had 13 SNPs encoding, including four non-synonymous amino acid changes, compared to the CDC Bethune reference ...
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Additional file 3: Figure S1. Boxplot diagram presenting Cd concentration (mg/kg dry weight) for each cultivar expressed specifically within vegetative tissues.
Additional file 1. Additional details pertaining to materials and methods for soil preparation, seeding and growth conditions, watering, tissue collection, Cd quantification and statistical analyses.
Additional file 2: Tables S1–S3. Results of the 1) two-way ANOVA to assess the effect of genotype, tissue, and the genotype-by-tissue interaction on Cd concentration in reproductive structures, 2) two-way ANOVA to assess the effect of... more
Additional file 2: Tables S1–S3. Results of the 1) two-way ANOVA to assess the effect of genotype, tissue, and the genotype-by-tissue interaction on Cd concentration in reproductive structures, 2) two-way ANOVA to assess the effect of genotype, age, and the genotype-by-age interaction in Cd concentration within vegetative tissues, and 3) two-way mixed ANOVA to assess the effect of genotype, tissue, and the genotype-by-tissue interaction on Cd concentration within developmental stages.
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High temperature stress of Brassica napus during ¯owering reduces micro- and megagametophyte fertility, induces fruit abortion, and disrupts seed production
Objective Humans consume low quantities of cadmium (Cd), a non-nutritive and potentially toxic heavy metal, primarily via the dietary intake of grains. A trial experiment was conducted to investigate physiological and developmental... more
Objective Humans consume low quantities of cadmium (Cd), a non-nutritive and potentially toxic heavy metal, primarily via the dietary intake of grains. A trial experiment was conducted to investigate physiological and developmental differences in Cd content in four flax cultivars (‘AC Emerson’, ‘Flanders’, ‘CDC Bethune’, and ‘AC McDuff’) as part of a study to provide information that will assist in the breeding of low Cd-accumulating flax cultivars. Our objective was to identify varietal differences in the uptake and distribution of Cd in various tissues among flax cultivars grown in naturally Cd-containing soil in a controlled environment. Results Cadmium concentration was dependent on genotype, developmental stage, and tissue type, as well as their interaction. Cadmium concentration was higher in roots and leaves, relative to all other tissues, with a general trend of decreasing Cd content over time within leaves and stems. Notably, the concentration of Cd was higher in ‘AC Emerso...
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Bulked segregant analysis implemented in MutMap and QTL-seq is a powerful and efficient method to identify agronomically important loci. However, the previous pipelines were not user-friendly to install and run. Here, we describe new... more
Bulked segregant analysis implemented in MutMap and QTL-seq is a powerful and efficient method to identify agronomically important loci. However, the previous pipelines were not user-friendly to install and run. Here, we describe new pipelines for MutMap and QTL-seq. These updated pipelines are approximately 5-8 times faster than the previous pipeline, are easier for novice users to use and can be easily installed through bioconda with all dependencies.
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ABSTRACT Brassica napus seed is composed of low density oil (0.92 g.cm−3) and higher density solids (1.3-1.45 g.cm−3). Seed buoyant density may potentially be used to determine seed oil content and to separate seeds with different oil... more
ABSTRACT Brassica napus seed is composed of low density oil (0.92 g.cm−3) and higher density solids (1.3-1.45 g.cm−3). Seed buoyant density may potentially be used to determine seed oil content and to separate seeds with different oil contents, however, we have found that seeds with the lowest buoyant density had lower than expected oil contents. It is proposed that the low oil content observed in the lowest density seed is a function of air gaps or pockets within the seed coat with sufficient volume to disrupt the linear relationship between oil content and density. The air gaps make density-based selection of seeds for oil content more difficult. Seed solid and liquid components are essentially incompressible with increased hydrostatic pressure but air gaps in seeds may be compressed or filled if density sorting is conducted in a pressurised apparatus. Experimental evidence shows that compression of air pockets with hydrostatic pressure or filling of air pockets with solvent simplifies the relationship between seed density and oil content. In spite of applied pressure it was observed that pressure was not sufficient to eliminate the buoyancy of all seeds with air pockets.Seeds containing air pockets may have been immature or improperly filled during maturation. Interrupted maturation, premature maturation or desiccation may potentially interrupt storage compound accumulation and lead to morphological changes. Chlorophyll fluorescence was used in this study as an indicator of seed maturity. An inverse relationship between chlorophyll content and oil content was observed, but was not observed for chlorophyll content and density. This relationship between oil content, chlorophyll content and density suggests that the lowest and highest density seed groups were enriched in immature seed.
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Research Interests: Chemistry, Peptide Science, Medicine, Biological Sciences, Biopolymers, and 12 moreCyclic peptides, Tandem Mass Spectrometry, Nitrogen Isotopes, High Pressure Liquid Chromatography, CHEMICAL SCIENCES, Protein Sequence Analysis, Seeds, Molecular weight, Amino Acid Sequence, Base Sequence, Flax, and Molecular Sequence Data
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Prunus virginiana L. (chokecherry) fruit has potential to provide both food and energy and as annual yield of biomass and energy are much greater than annual crops such as canola and wheat. We determined chokecherry fruit weight fractions... more
Prunus virginiana L. (chokecherry) fruit has potential to provide both food and energy and as annual yield of biomass and energy are much greater than annual crops such as canola and wheat. We determined chokecherry fruit weight fractions as well as pit and extracted seed oil concentrations and fatty acid composition. Gross energy for each of the fractions was determined, as were carbon and nitrogen content. Extrapolation of these data suggests that gross energy from pits alone over a 24-year period (890 GJ·ha(-1)) is equivalent to that from an entire canola/wheat rotation (850 GJ·ha(-1)). After maturity, pulp contributes an additional 1130 GJ·ha(-1) over 21 years from ~3.4 t·ha(-1)·year(-1) (dw), while wood from pruning could add another 60 GJ·ha(-1)·year(-1). Over this time period, chokecherry would produce 1.5-2.5 times the amount of oil produced by a canola/wheat rotation.
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A polymerase chain reaction (PCR) assay was developed for the detection of alcelaphine herpesvirus 1 (AHV1), a causative agent of malignant catarrhal fever (MCF) of ruminants. A pair of 20-base primers was constructed based on the... more
A polymerase chain reaction (PCR) assay was developed for the detection of alcelaphine herpesvirus 1 (AHV1), a causative agent of malignant catarrhal fever (MCF) of ruminants. A pair of 20-base primers was constructed based on the published nucleotide sequence of gene A of the WC11 isolate of AHV1 and was used to amplify a DNA fragment of 413 base pairs. The optimised PCR assay was highly sensitive, i.e. it detected 10 fg of genomic DNA of AHV1 (WC11 isolate). The amplified fragment was shown to be specific for AHV1 DNA by (i) cleavage withXbaI which yielded 2 subfragments of approximately 140 and 280 base pairs and (ii) chemiluminescence Southern blot hybridisation with a digoxigenin-labelled 25-base internal probe. The PCR assay also amplified AHV1 gene sequences in tissue samples from deer and rabbits experimentally infected with materials derived from deer with clinical sheep-associated MCF.
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The accumulation of carotenoids in higher plants is regulated by the environment, tissue type and developmental stage. In Brassica napus leaves, β-carotene and lutein were the main carotenoids present while petals primarily accumulated... more
The accumulation of carotenoids in higher plants is regulated by the environment, tissue type and developmental stage. In Brassica napus leaves, β-carotene and lutein were the main carotenoids present while petals primarily accumulated lutein and violaxanthin. Carotenoid accumulation in seeds was developmentally regulated with the highest levels detected at 35–40 days post anthesis. The carotenoid biosynthesis pathway branches after the formation of lycopene. One branch forms carotenoids with two β rings such as β-carotene, zeaxanthin and violaxanthin, while the other introduces both β- and ε-rings in lycopene to form α-carotene and lutein. By reducing the expression of lycopene ε-cyclase (ε-CYC) using RNAi, we investigated altering carotenoid accumulation in seeds of B. napus. Transgenic seeds expressing this construct had increased levels of β-carotene, zeaxanthin, violaxanthin and, unexpectedly, lutein. The higher total carotenoid content resulting from reduction of ε-CYC expression in seeds suggests that this gene is a rate-limiting step in the carotenoid biosynthesis pathway. ε-CYC activity and carotenoid production may also be related to fatty acid biosynthesis in seeds as transgenic seeds showed an overall decrease in total fatty acid content and minor changes in the proportions of various fatty acids.
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Research Interests: Plant Biology, Fertility, Stress, Seed production, Pollen, and 19 moreGametophyte, Experimental Botany, Flowers, Seed Development, High Temperature, Germination, Experimental, Brassica Napus, Seeds, Time Factors, Acclimatization, Heat Shock Proteins, Heat Shock Protein, Pollen Tube Growth, Knock out, Cell Survival, PLANT PROTEINS, *Hot Temperature, and Pollen tube
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Research Interests: Microbiology, Medical Microbiology, Cell Culture, Cercopithecus aethiops, Animals, and 11 moreNew Zealand, Polymerase Chain Reaction, Journal of Virological Methods, POULTRY DISEASES, Chickens, Amino Acid Sequence, Base Sequence, Sensitivity and Specificity, Embryos, Vero cells, and Molecular Sequence Data
Research Interests: Microbiology, Medical Microbiology, Cell Culture, Cercopithecus aethiops, Animals, and 11 moreNew Zealand, Polymerase Chain Reaction, Journal of Virological Methods, POULTRY DISEASES, Chickens, Amino Acid Sequence, Base Sequence, Sensitivity and Specificity, Embryos, Vero cells, and Molecular Sequence Data
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Transcriptional activity of a 573-bp fragment of HSP101 (At1g74310) incorporated into a Mutator-like element (MULE) transposon was investigated in Arabidopsis thaliana Columbia. Sequence identity between the HSP101-MULE arrangement and a... more
Transcriptional activity of a 573-bp fragment of HSP101 (At1g74310) incorporated into a Mutator-like element (MULE) transposon was investigated in Arabidopsis thaliana Columbia. Sequence identity between the HSP101-MULE arrangement and a continuous segment of the original HSP101 promoter, 5' UTR exon, and open reading frame (ORF) was high (87%) but lower in the 5' UTR intron (69%). Collectively, the HSP101 ORF, the MULE 5' terminal inverted repeat (TIR), and the 1.3 kb immediately upstream of the TIR is located on chromosome IV, and we refer to it as HSP101B. Located within the HSP101B promoter, upstream of 2 heat shock elements (HSEs), are 4 COR15a-like low-temperature response elements (LTREs). The HSP101B ORF was transcribed in the leaves and influorescences of high-temperature stress (HTS) treated Arabidopsis thaliana but not in low-temperature stress (LTS) and control plants. Transiently transformed Arabidopsis seedlings, as well as stable transformed lines of Linum usitatissimum (flax) and Brassica napus (canola) containing a HSP101B promoter:GUS construct, showed either LTS-, or LTS- and HTS-, induced beta-glucuronidase expression. Results from PCR amplifications of HpaII- and MspI-digested Arabidopsis genomic DNA suggest that endogenous expression of HSP101B may be downregulated by partial methylation of the HSP101B sequence between the TIRs of the associated MULE.
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Low-temperature (LT) tolerance in winter wheat (Triticum aestivum L.) is an economically important but complex trait. Four selected wheat genotypes, a winter hardy cultivar, Norstar, a tender spring cultivar, Manitou and two near-isogenic... more
Low-temperature (LT) tolerance in winter wheat (Triticum aestivum L.) is an economically important but complex trait. Four selected wheat genotypes, a winter hardy cultivar, Norstar, a tender spring cultivar, Manitou and two near-isogenic lines with Vrn-A1 (spring Norstar) and vrn-A1 (winter Manitou) alleles of Manitou and Norstar were cold-acclimated at 6°C and crown and leaf tissues were collected at 0, 2, 14, 21, 35, 42, 56 and 70 days of cold acclimation. cDNA-AFLP profiling was used to determine temporal expression profiles of transcripts during cold-acclimation in crown and leaf tissues, separately to determine if LT regulatory circuitries in crown and leaf tissues could be delineated using this approach. Screening 64 primer combinations identified 4,074 and 2,757 differentially expressed transcript-derived fragments (TDFs) out of which 38 and 16% were up-regulated as compared to 3 and 6% that were down-regulated in crown and leaf tissues, respectively. DNA sequencing of TDFs revealed sequences common to both tissues including genes coding for DEAD-box RNA helicase, choline-phosphate cytidylyltransferase and delta-1-pyrroline carboxylate synthetase. TDF specific to crown tissues included genes coding for phospahtidylinositol kinase, auxin response factor protein and brassinosteroid insensitive 1-associated receptor kinase. In leaf, genes such as methylene tetrahydrofolate reductase, NADH-cytochrome b5 reductase and malate dehydrogenase were identified. However, 30 and 14% of the DNA sequences from the crown and leaf tissues, respectively, were hypothetical or unknown proteins. Cluster analysis of up-, down-regulated and unique TDFs, DNA sequence and real-time PCR validation, infer that mechanisms operating in crown and leaf tissue in response to LT are differently regulated and warrant further studies.
Research Interests: Genetics, Plant Biology, Plant Molecular Biology, real time PCR, Cluster Analysis, and 14 moreAcclimatization, Winter Wheat, Low Temperature, Base Sequence, Complex Traits, Triticum, Cold Acclimation, Triticum aestivum L., Biochemistry and cell biology, Gene expression profiling, Plant Leaves, Cold climate, DNA sequence, and Differential expression
Two aquaporin genes were isolated from a cDNA library of canola (Brassica napus L.). The first aquaporin, BnPIP1 of 1094 bp, encoding a putative polypeptide of 287 amino acids with a predicted molecular mass of 30.4 kDa and a pI of 7.8,... more
Two aquaporin genes were isolated from a cDNA library of canola (Brassica napus L.). The first aquaporin, BnPIP1 of 1094 bp, encoding a putative polypeptide of 287 amino acids with a predicted molecular mass of 30.4 kDa and a pI of 7.8, belongs to the family of plasma membrane intrinsic protein (PIPs) aquaporins. The B. napus aquaporin showed 85–94% identity to the Arabidopsis thaliana PIPs. ABA priming of seed induced high levels of BnPIP1 transcript which remained after subsequent re-drying of the seed. The second aquaporin, Bnγ-TIP2 of 1020 bp, encoded a putative polypeptide of 253 amino acids with a predicted molecular mass of 25.8 kDa and a pI of 5.8. Bnγ-TIP2 showed 83–90% identity to γ-TIP genes from a variety of plant species. Bnγ-TIP2 was expressed only when radicle protrusion occurred in either untreated or primed seeds. Seeds primed with PEG or ABA germinated earlier and showed a higher final percentage of germination than unprimed seed, particularly under salt and osmotic stresses at low temperature. Transcripts of both BnPIP1 and Bnγ-TIP2 genes were present earlier during germination of primed seeds than non-primed seed. From these results, we conclude that BnPIP1 is related to the water transportation required for enzymatic metabolism of storage nutrients at the early stages of canola seed germination whereas Bnγ-TIP2 expression is related to cell growth associated with radicle protrusion. Priming induced the expression of BnPIP1 but had no effect on Bnγ-TIP2.