Project description:This experiment aims to determine the genes that respond to protoplasting treatment in a time course of Arabidopsis seed germination, so that they can be filtered out from single-cell RNA-seq analysis which involves protoplasting.
Project description:Lotus (Nelumbo nucifera Gaertn) belongs to the family Nymphaeaceae, and is a popular aquatic vegetable that is rich in nutrients. It is widely cultivated in China, and many varieties of lotus are used for different purposes, suited to different climates, and consumed in different ways. Lotus is commonly produced by asexual propagation, so mutation through hybridization and variation fixed by asexual propagation are the main ways to create new varieties. Therefore, the formation of adventitious roots (ARs) in lotus, which does not have a well-developed principal root, is an important part of growth and development. It would be very useful to control ARs formation for lotus production and breeding.
Project description:Some flowering plant and vertebrate genes are expressed primarily or exclusively from either the maternal or paternal allele, a phenomenon called genomic imprinting. Flowering plant imprinted gene expression has been described primarily in endosperm, a terminal nutritive tissue consumed by the embryo during seed development or after germination. Imprinted expression in Arabidopsis thaliana endosperm is orchestrated by differences in cytosine DNA methylation between the paternal and maternal genomes, as well as by Polycomb group (PcG) proteins. Currently only eleven imprinted Arabidopsis genes are known. Here we use extensive sequencing of cDNA libraries to identify many new paternally and maternally imprinted genes in A. thaliana endosperm, including transcription factors, proteins involved in hormone signaling, and epigenetic regulators. The imprinted status of many maternally-expressed genes is not altered by mutations in the DNA-demethylating glycosylase DEMETER, the DNA methyltransferase MET1 or the core PcG protein FIE, indicating that these genes are regulated by novel mechanisms or deposited from maternal tissues. We did not find any imprinted genes in the embryo. Our results demonstrate that imprinted gene expression, particularly from the maternal genome, is an extensive, mechanistically complex phenomenon that likely affects multiple aspects of seed development. Epigenetics Examination of genomic imprinting in Arabidopsis endosperm
Project description:The plant cell wall performs a number of essential functions including providing shape to many different cell types and serving as a defense against potential pathogens. The net pattern mutation creates breaks in the seed coat of soybean (Glycine max) because of ruptured cell walls. Using RNA-Seq, we examined the seed coat transcriptome from three stages of immature seed development in two pairs of isolines with normal or defective seed coat phenotypes due to the net pattern. The genome-wide comparative study of the transcript profiles of these isolines revealed 364 differentially expressed genes in common between the two varieties that were further divided into different broad functional categories. Genes related to cell wall processes accounted for 19% of the differentially expressed genes in the middle developmental stage of 100-200 mg seed weight. Within this class, the cell wall proline-rich and glycine-rich protein genes were highly differentially expressed in both genetic backgrounds. Other genes that showed significant expression changes in each of the isoline pairs at the 100-200 mg seed weight stage were xylem serine proteinase, fasciclin-related genes, auxin and stress response related genes, TRANSPARENT TESTA 1 (TT1) and other transcription factors. The mutant appears to shift the timing of either the increase or decrease in the levels of some of the transcripts. The analysis of these data sets reveals the physiological changes that the seed coat undergoes during the formation of the breaks in the cell wall. Examination of soybean isolines in two different genetic background at three different seed weight stages: Seed coats of Clark standard (CS, wild type) & Clark defective (CD, seed coat mutant), Harosoy Standard (HS) & Harosoy defective (HD) at 50-100mg, 100-200mg and 400-500mg.
Project description:Five degradome libraries were constructed from three different seed developmental stages. Separate degradome libraries were constructed for seed coat and cotyledons to identify the tissue specific miRNAs and their potential targets. Sequencing and analysis of degradome libraries gives identification of 183 different targets for 80 known soybean miRNAs. We found 30 cotyledon specific, 18 seed coat specific and 32 miRNAs found in both tissues irrespective of the developmental stages. One interesting observation is that we found more miRNA targets in late seed developmental stages than earlier stages. Additionally, we have validated four different auxin response factor genes as targets for gma-miR160 via RNA ligase mediated 5? rapid amplification of cDNA ends (RLM-5?RACE). GO analysis indicated the enrichment of miRNA target genes in seed development. Construction of degradome libraries using cotyledons and seed coats from 3 different developmental stages
Project description:We present results from deep sequencing of small RNA populations from several genotypes of soybean and demonstrate that the CHS siRNAs accumulated only in the seed coats of the yellow varieties having either the dominant I or i-i alleles and not in the pigmented seed coats with homozygous recessive i genotypes. However, the diagnostic CHS siRNAs did not accumulate in the cotyledons of genotypes with the dominant I or i-i alleles thus demonstrating the novelty of an endogenous inverted repeat region of CHS genes driving RNA silencing in trans of non-linked CHS family members in a tissue-specific manner. The phenomenon results in inhibition of a metabolic pathway by siRNAs in one tissue allowing expression of the flavonoid pathway and synthesis of secondary metabolites in other organs as the chalcone synthase small RNAs are found in the seed coats of yellow seeded soybean varieties but not in the cotyledons of the same genotype. In order to compare the population of chalcone synthase related small RNAs, we sequenced 3 to 6 million small RNAs using the Illumina Genome Analyzer from the following four soybean cultivars and tissues with specific genotypes at the I locus: Richland immature seed coats (homozygous for the dominant I allele that specifies yellow seed coat); Williams immature seed coats (homozygous for the dominant i-i allele that specifies yellow seed coat with pigmented hilum) Williams (i-i/i-i yellow) immature cotyledons (homozygous for the dominant i-i allele that specifies yellow seed coat with pigmented hilum); Williams 55 immature seed coats (a Williams isogenic line homozygous for the recessive i allele that specifics pigmented seed coats. All seed coats and cotyledons were dissected from green stage immature seeds within the fresh weight range of 50-75 mg.
Project description:Transient genetic modification of plant protoplasts is a straightforward and rapid technique for the analysis of numerous aspects of plant biology. One drawback in the analysis of transformed protoplast suspensions is that they are a heterogeneous mix of cells that have and have not been successfully transfected. To overcome this problem, we have developed a system that employs a fluorescent positive selection marker in combination with flow cytometric analysis as well as fluorescence activated cell sorting (FACS) to isolate responses in the transfected protoplasts exclusively. This recombinase-compatible system enables high-throughput screening of genetic circuitry. Moreover, the use of FACS allows in depth downstream analysis. Lastly, over-expression is an effective means to dissect regulatory networks, especially where redundancy exists. Here, this system has been applied to the study of auxin signaling in order to investigate reporter gene activation and genome-wide transcriptional changes in response to manipulation of the auxin-response network. We have transiently over-expressed dominant negative mutant isoforms of Aux/IAA transcription factors (IAA7mII and IAA19mII; Tiwari et al., 2001) in Arabidopsis Pwer::GFP root protoplasts, making use of a RFP fluorescent positive selection marker and FACS to isolate the dually labeled (IAAnmII expressing and Pwer::GFP-positive) cells. We have compared the transcriptional differences between an empty vector control, IAA7mII and IAA19mII protoplasts that had either been treated with 5microM IAA or mock-treated for 3 hours. Experiment Overall Design: 18 samples with 3 replicates for each condition and transformation vector: 3x empty vector mock treated, 3x empty vector IAA treated, 3x IAA7mII over-expressor mock treated, 3x IAA7mII over-expressor IAA treated, 3x IAA19mII over-expressor mock treated and 3x IAA19mII over-expressor IAA treated.
Project description:Developmental transitions can be described in terms of morphology and individual genes expression patterns, but also in terms of global transcriptional and epigenetic changes. Most of the large-scale studies of such transitions, however, have only been possible in synchronized cell culture systems. Here we generate a cell type specific transcriptome of an adult stem-cell lineage in the Arabidopsis leaf using RNA sequencing and microarrays. RNA profiles of stomatal entry, commitment, and differentiating cells, as well as of mature stomata and the entire aerial epidermis give a comprehensive view of the developmental progression. To obtain pure cell populations corresponding to different stomatal lineage cell types we used Fluorescent Activated Cell Sorting (FACS) in combination with markers of early (SPCHp::SPCH-YFP, SSY), middle (MUTEp::nucGFP, MG), and late (FAMAp::GFP-FAMA, FGF) precursor stages, as well of mature stomata (enhancer trap E1728::GFP, E1728G) and a marker of the entire epidermis (ML1p::YFP-RCI2A, ML1Y). To minimize transcriptional differences due to age, all cell types were sorted from 10-day old aerial rosettes, and the specificity of expression pattern at this common time point confirmed via confocal microscopy. Total RNA was extracted from purified protoplasts (4,000 to 20,000 cells/replicate; 2 replicates/marker line; 3 replicates/SSY marker line) and transcript abundance measured using RNA sequencing.
Project description:The seed coat of black (iRT) soybean with the dominant R allele begins to accumulate cyanic pigments at the transition stage of seed development (300 – 400 mg fresh seed weight), whereas the brown (irT) nearly-isogenic seed coat with the recessive r allele lacks cyanic pigments at all stages of seed development. We used microarrays to determine global gene expression differences between black (iRT) and brown (irT) soybean seed coats at the transition stage of seed development (300 – 400 mg fresh seed weight). To identify the complete set of gene transcripts that are differentially expressed between the seed coats of black (iRT) and brown (irT) Clark isolines, seed coats were dissected at the transition stage of seed development (300 – 400 mg fresh seed weight) for microarray analysis using the Affymetrix Soybean GeneChip. To ensure seed coats were of the same stage of development, the days post anthesis, pod length, pod color, embryo morphology, and transcript levels of the developmental marker gene Gm-r1083-1191, a putative cutin biosynthesis gene, and DFR1 were ensured to be equivalent between black (iRT) and brown (irT) isolines.
Project description:Developmental transitions can be described in terms of morphology and individual genes expression patterns, but also in terms of global transcriptional and epigenetic changes. Most of the large-scale studies of such transitions, however, have only been possible in synchronized cell culture systems. Here we generate a cell type specific transcriptome of an adult stem-cell lineage in the Arabidopsis leaf using RNA sequencing and microarrays. RNA profiles of stomatal entry, commitment, and differentiating cells, as well as of mature stomata and the entire aerial epidermis give a comprehensive view of the developmental progression. To obtain pure cell populations corresponding to different stomatal lineage cell types we used Fluorescent Activated Cell Sorting (FACS) in combination with markers of early (SPCHp::SPCH-YFP, SSY), middle (MUTEp::nucGFP, MG), and late (FAMAp::GFP-FAMA, FGF) precursor stages, as well of mature stomata (enhancer trap E1728::GFP, E1728G) and a marker of the entire epidermis (ML1p::YFP-RCI2A, ML1Y). To minimize transcriptional differences due to age, all cell types were sorted from 14-day old aerial rosettes, and the specificity of expression pattern at this common time point confirmed via confocal microscopy. Total RNA was extracted from purified protoplasts (2,000 to 20,000 cells/replicate; 3 replicates/marker line) and transcript abundance measured using ATH1-121501 microarrays.