Project description:Global transcript profiling of Arabidopsis dgat1-1 seed at different stages of embryo development was used to identify differentially expressed genes in the mutant compared to wild-type (Col-0) seed. These genes provided information about the remodeling of lipid metabolism and TAG synthesis in response to the lack of DGAT1 activity.
Project description:Medicago truncatula Tnt-1 insertional mutant for MtTTG1 gene (NF977) versus the wild-type R108. The seed samples are harvested at 16 days after pollination. Their transcript profiles were compared.
Project description:The role of non-CG methylation in seed development and dormancy remains unknown. There are four genes in charge of non-CG methylation in Arabidopsis: drm1, drm2, cmt2 and cmt3. The majority of non-CG methylation in vegetative tissues, leaf, is gone in homozygous ddcc mutant line (Hume et al., 2014). To uncover the possible role of non-CG DNA methylation in seed development and dormancy, we characterized the methylome of ddcc mutant in Arabidopsis postmature-green-stage seed and dry seed using Illumina sequencing. Meanwhile, vegetative tissue, leaves from 3 week plant with ddcc mutant and from wild-type, and postmature-green-stage seed and dry seed from wild-type plant were used as control.
Project description:Developing Arabidopsis seeds accumulate oils and seed storage proteins synthesized by the pathways of primary metabolism. Seed development and metabolism are positively regulated by transcription factors belonging to the LAFL regulatory network. The VAL gene family encodes repressors of the seed maturation program in germinating seeds, although they are also expressed during seed maturation. VAL1 functions as a repressor of seed metabolism, as val1 mutant seeds accumulated elevated levels of storage proteins compared to the wild type. Two VAL1 splice variants were identified through RNA sequencing analysis: a full-length and a truncated form lacking the plant-homeodomain-like domain associated with epigenetic repression. None of the transcripts encoding the core LAFL network transcription factors were affected in val1 embryos. Instead, activation of VAL1 by FUSCA3 appears to result in repression of a subset of seed maturation genes downstream of core LAFL regulators as 39% of transcripts in the FUSCA3 regulon were de-repressed in the val1 mutant. The LEC1 and LEC2 regulons also responded but to a lesser extent. Additional 832 transcripts that were not LAFL targets were de-repressed in val1 mutant embryos. These transcripts are candidate targets of VAL1, acting through epigenetic and/or transcriptional repression.
Project description:The lemma, the palea and the awn of a barley spike are photosynthetic organs and supply the developing seed with carbohydrates. In addition, the lemma and the palea cover the seed and protect it from pathogens and insects. In this study, we compared gene expression among the lemma, the palea, the awn and the developing seed of barley at the grain-filling stage (Zadok scale 83) using the Barley1 Genome Array in order to identify genes that determine the primary function of these organs. Experiment Overall Design: Lemma, palea, awn and seed were collected at grain-filling stage (Zadok scale 83) to compare differences in gene expression. For each organ three biological replications were collected on three different dates. On each of the three dates, one replication of each organ was collected from plants grown in separate pots using a randomized complete block design (RCBD). In ths design, organ type was the treatment effect and date of sample collection (replication) was the block. To get enough tissue for RNA extraction, each replication for each organ was collected from four plants in the same pot. RNA from each replicate sample was hybridized to individual Barley1 GeneChips. Thus, for four organs with three replications (blocks), a total of 12 Barley1 GeneChips were used.
Project description:Identification of key genes and pathways regulated by phytohormone ABA during maize seed maturation, using the ABA synthesis-deficient mutant (vp5) and regular maize (Vp5) developing embryos.
Project description:Developing Arabidopsis seeds accumulate oils and seed storage proteins synthesized by the pathways of primary metabolism. Seed development and metabolism are positively regulated by transcription factors belonging to the LAFL regulatory network. The VAL gene family encodes repressors of the seed maturation program in germinating seeds, although they are also expressed during seed maturation. VAL1 functions as a repressor of seed metabolism, as val1 mutant seeds accumulated elevated levels of storage proteins compared to the wild type. Two VAL1 splice variants were identified through RNA sequencing analysis: a full-length and a truncated form lacking the plant-homeodomain-like domain associated with epigenetic repression. None of the transcripts encoding the core LAFL network transcription factors were affected in val1 embryos. Instead, activation of VAL1 by FUSCA3 appears to result in repression of a subset of seed maturation genes downstream of core LAFL regulators as 39% of transcripts in the FUSCA3 regulon were de-repressed in the val1 mutant. The LEC1 and LEC2 regulons also responded but to a lesser extent. Additional 832 transcripts that were not LAFL targets were de-repressed in val1 mutant embryos. These transcripts are candidate targets of VAL1, acting through epigenetic and/or transcriptional repression. 2 genotypes, 7 time points, 3 biological and 4 technical replicates
Project description:Transfected siRNAs and miRNAs regulate numerous transcripts that have only limited complementarity to the active strand of the RNA duplex. This process reflects natural target regulation by miRNAs, but is an unintended (“off-target”) consequence of siRNA-mediated silencing. Here we demonstrate that this unintended off-target silencing is widespread, and occurs in a manner reminiscent of target silencing by miRNAs. A high proportion of unintended transcripts silenced by siRNAs showed 3’ UTR sequence complementarity to the seed region of the siRNA. Base mismatches within the siRNA seed region reduced the set of original off-target transcripts but generated new sets of silenced transcripts with sequence complementarity to the mismatched seed sequence. An inducible shRNA silenced a subset of transcripts that were silenced by an siRNA of the same sequence, demonstrating that unintended silencing is sequence-mediated and is independent of delivery method. In all cases, off-target transcript silencing was accompanied by loss of the corresponding protein and occurred with similar dependence on siRNA concentration as silencing of the target transcript. These results demonstrate that short stretches of sequence complementarity to the seed region of the siRNA are key to the silencing of unintended transcripts, and that this limits the specificity of siRNA-mediated transcript silencing. Because these off-target events are sequence-dependent, inclusion of multiple independent siRNAs to the target of interest can help to distinguish true positives from false positives in functional genetic analyses. Keywords: siRNA, RNAi, sequence alignment, off-target, seed region
Project description:Purpose: To elucidate the physiological and molecular mechanisms underlying seed development, we conducted a genome-wide transcriptional profiling of developing seeds of ‘Sarsyun’ at four different time points (21, 28, 35, and 42 DAF). 34,423 contigs from four different developing seeds (21, 28, 35, and 42 DAF) were analyzed for transcript abundance and changes to the timing of transcript abundance in relation to the accumulation of seed storage products. Most genes involved in seed photosynthesis and carbohydrate metabolism were highly expressed at 21 or 28 DAF and were subsequently downregulated. Expression of genes coding for oleosins and fatty acid synthesis and elongation markedly increased at 28 DAF through 35 DAF, respectively, remaining high thereafter. Expression of major storage protein genes increased at 28 or 35 DAF. Overall, our results showed that dynamic changes to transcript abundance of most genes in relation to seed storage products occurred between 28 and 35 DAF.
Project description:The role of on-CG methylation in seed development and dormancy remains unknown. There are four genes in charge of non-CG methylation in Arabidopsis: drm1, drm2, cmt2 and cmt3. The majority of non-CG methylation in vegetative tissues, leaf, is gone in homozygous ddcc mutant line (Hume et al., 2014). To uncover the possible role of non-CG DNA methylation in seed development and dormancy, we characterized the methylome of ddcc mutant in Arabidopsis dry seed using Illumina sequencing. Meanwhile, vegetative tissue, leaves from 3 week plant with ddcc mutant and from wild type, and dry seed from wild type plant were used as control. Illumina sequencing of bisulfite-converted genomic DNA from dry seed and 3-week-plant leaves of ddcc mutant and wild type.