Project description:Wheat seed development is a very important stage in the cereal crops seed life cycle. The accumulation reserves of wheat mature seeds provide not only the food for human and livestock feed, but also the energy for the seed germination.However, due to the large genome size, many studies related to wheat seed are very complex and uncompleted. Transcriptome analysis of elite Chinses bread wheat cultivar Jimai 20 may provides a comprehensive understanding of wheat seed development. Seed development involves in the regulation of large number of genes, whether these genes are normal activated or not is very important to seed development. We performed microarray analysis using the Affymetrix Gene Chip to reveal the gene expression profiles in the phases of wheat cultivar Jimai 20 grain filling. Our results provide a new insights into the thoroughly metabolic changes of seed development as well as the key differentially expressed genes involved in wheat grain development.
Project description:In this study, two cDNA libraries for the developing grain and leaf-stem components of common wheat cultivar Nongda211 were constructed. We plan to study the genes which are differentially expressed in the grain.
Project description:Grain yield and protein content were determined for six wheat cultivars grown over three years at multiple sites and at multiple N-fertilizer inputs. Although grain protein was negatively correlated with yield, some grain samples had higher protein contents than expected based on their yields, a trait referred to as grain protein deviation (GPD). We used novel statistical approaches to calculate GPD across environment and to correlate gene expression in the developing caryopsis with this trait. The yield and protein content were initially adjusted for nitrogen fertilizer inputs, and then adjusted for yield (to remove the negative correlation) resulting in environmental corrected GPD. The transcriptome data for all samples were subjected to Principal Component Analysis (PCA) and ANOVA to identify individual Principal Components (PCs) correlating with GPD alone. Scores of the selected PCs significantly related to cultivar differences and GPD but not to the yield or protein content were identified as reflecting a multivariate pattern of gene expression related to genetic variation in GPD. Sets of genes significant for these PCs and hence GPD were identified as candidate genes determining cultivar differences in GPD. Microarray profiling has been used to identify the links between gene expression and grain protein content in 6 different varietes of wheat grown at 2 different sites, 3 N levels and during 3 growth seasons.
Project description:Proanthocyanidin (PA) is a polymeric flavonoid found in the seed coat of many plant species, including wheat, and is responsible for the red grain colour of most wheat cultivars. White wheat cultivars that lack PA have null mutations in all three homoeologues of the gene encoding the R myb transcription factor. Previous work has shown that R control several genes in the PA biosynthetic pathway. The aim of this experiment was to identify other components of the PA pathway of wheat controlled by R through comparison of transcript levels in tissues of developing grain of red and white near-isogenic lines of the cultivar Holdfast. Note: RNA-seq reads from the Red samples in this experiment have previously been submitted to ENA under the accession number E-MTAB-3103.
Project description:A microarray analysis of wheat grain hardness For both the Heron and Falcon NIL, whole wheat heads were harvested at 6, 15 and 25 days post anthesis (DPA) from glass house grown material and stored at -80 OC. For the other wheat cultivars analysed, heads at approximately 9-10 DPA were used. Eight to ten developing caryopses at the same age and morphological stage of development were selected from a head to represent a sample. Seed collected from a different head represented a replicate sample. Total RNA was isolated from the whole seed following the method of Higgins et al. (1976) with the following modification to remove starch. After the lithium chloride precipitation, the RNA pellet was resuspended in 250 ?l water. Then 3.5 ?l of 3 M sodium acetate (pH 5.3) and 125 ?l ethanol were added and the sample was centrifuged for 10 minutes at 4 OC. The supernatant was transferred to a fresh tube and the RNA was ethanol-precipitated by the addition of 21.5 ?l of 3 M sodium acetate (pH 5.3) and 375 ?l ethanol. The recovery of RNA varied from 0.06-0.5 ?g RNA per mg of tissue and this was dependent on the developmental stage of the seeds used for extraction of the RNA. For the labelling procedure, 50 ?g of total RNA was used for both the Cy3 and Cy5 dyes (Amersham Pharmacia, UK), following the two-step labelling method of Schenk et al. (2000). The Cy3 control (hard wheat) and Cy5 sample (soft wheat) were swapped among the replicate experiments to minimise any bias in cDNA incorporation and photo-bleaching of the fluorescent dyes. The pre-hybridisation of the microarray slides, hybridisation of the target cDNA and subsequent washing of the slides to remove unbound target was performed as per the supplied protocol for the CMT-GAPSTM coated microscope slides (Corning USA). The slides were scanned with a GenePix 4000A microarray scanner (Axon Instruments, Union, CA, USA). The features were analysed using the GenePix Pro 4 software and unsatisfactorily segmented features were either manually adjusted or discarded to ensure the integrity of the data obtained.
Project description:To provide a global study of transcriptome changes under drought stress, the gene expression levels of a durum wheat genotype (Triticum durum Desf. cultivar Creso) and two bread wheat genotypes (Triticum aestivum L. cultivar Chinese Spring -CS- and its deletion line CS_5AL-10) were investigated. The 5A chromosome deletion line (5AL-10) lacks the distal part (43%) of the long arm of chromosome 5A. Each genotype was subjected to two different levels of water stress at the grain filling stage. After anthesis, three different levels of soil water content (SWC) were induced as described below: control (CTRL; SWC=28%), moderate stress (MS; SWC=18%), and severe stress (SS; SWC=12.5%). For each sample, three biological replicates were performed, for a total of 27 hybridizations. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Alessio Aprile. The equivalent experiment is TA23 at PLEXdb.]
Project description:Wheat is one of the most significant crops in terms of human consumption in the world. In a climate change scenario, extreme weather event such as heatwaves will be more frequent especially during the grain-filling (GF) stage and could affect grain weight and quality of crops. Molecular mechanisms underlying the response to short heat stress (HS) have been widely reported for the hexaploid wheat (Triticum aestivum) but the regulatory heat stress mechanisms in tetraploid durum wheat (Triticum turgidum ssp. durum) remain partially understood. In this work, we performed a transcriptomic analysis of durum wheat grains to HS during early GF to identify key HS response genes and their predicted regulatory networks under glasshouse conditions.
Project description:Grain length is a prominent determinant for the grain weight and appearance quality of rice. To elucidate the genetic basis of the control of grain length, we conducted quantitative trait locus (QTL) mapping to determine a genomic interval responsible for the a long-grain phenotype observed in a japonica cultivar HD385 by using an F2:3 population and recombinant inbred line (RIL) population, which is are derived from a cross between the long-grain japonica cultivar HD385 and short-grain japonica cultivar Nipponbare (NIP). This led to the identification of a novel QTL, which is located on chromosome 3, for grain length, named qIGL1 (for Increased Grain Length 1); the HD385-derived allele showed enhancement effects on grain length, and such an allele as well as NIP-derived allele are were thus designated qigl1 HD385 and qIGL1NIP, respectively. Genetic analysis revealed that qigl1HD385 displayed semi-dominant effects on grain length. To further narrow down the qIGL1 region, we developed a few advanced backcross populations to determine the precise location of qIGL1. Eventually, qIGL1 was delimited to a 70.8-kb region containing 9 open reading frames (ORFs). A comprehensive analysis indicated that ORF6 and ORF9, separately corresponding to LOC_Os03g30530 and LOC_Os03g30550, are were found to carry base substitutions and/or deletions, which resulted in changes or losses of amino acid residues. However, these alterations in coding sequences does did not significantly change the expression levels of both ORFs. To further elucidate the mechanisms behind the increases of grain length conferred by qigl1HD385, we generated a pair of near-isogenic lines (NILs), termed NIL-qigl1HD385 and NIL-qIGL1NIP, and discovered that introduction of qigl1HD385 into the NIP background significantly lead resulted into the elevations of grain length and 1000-grain weight. Closer inspection of outer epidermal cells of grain surfaces of both lines revealed that the cell length and width in the longitudinal direction are were significantly longer in NIL-qigl1HD385 compared with in NIL-qIGL1NIP, which may might stem partly from the downregulation of several cell cycle-related genes. Hence, our study studies identify identified a new semi-dominant natural allele contributing to the increase of grain length, and further shed light on the regulatory mechanisms of grain length.
Project description:Allohexaploid bread wheat (Triticum aestivum, L.) provides ~ 20% of calories consumed by humans. Hitherto lack of genome sequence for the three homoelogous and highly similar bread wheat genomes (A, B and, D) impeded expression analysis of the grain transcriptome. We used novel genome information to analyze the cell type specific expression of homeologous genes in the developing wheat grain.