Project description:MicroRNAs (miRNAs) are essential small RNA molecules that regulate the expression of target mRNAs in plants and animals. Here, we aimed to identify miRNAs and their putative targets in Hibiscus syriacus, the national flower of South Korea. Therefore, we employed high-throughput sequencing of small RNAs obtained from four different tissues (i.e., leaf, root, flower, and ovary) and identified 33 conserved and 30 novel miRNA families, many of which showed differential tissue-specific expressions. In addition, we computationally predicted novel targets of miRNAs and validated some of them using 5′ rapid amplification of cDNA ends analysis. One of the validated novel targets of miR477 was a terpene synthase, the primary gene involved in the formation of disease-resistant terpene metabolites such as sterols and phytoalexins. In addition, a predicted target of conserved miRNAs, miR396, is SHORT VEGETATIVE PHASE, which is involved in flower initiation and is duplicated in Hibiscus syriacus. Collectively, this study provides the first reliable draft of the Hibiscus syriacus miRNA transcriptome that should constitute a basis for understanding the biological roles of miRNAs in Hibiscus syriacus.
Project description:Here we show for the first time that vesicle fusion is one of multiple pathways in plant cells involved in terpene emissions. We demonstrate a positive feedback on terpene production when vesicle fusion is inhibited in cells producing high levels of terpenes, which relates to an induced proteasome malfunction.
Project description:This study explores the changes in histone modifications of sorghum bicolor through developmental stages and in response to drought stress in two sorghum genotypes. We analyzed the leaves of 48 plants using top-down mass spectrometry and identified 26 unique histone proteins and 677 unique histone proteoforms. We detected trimethylation on nearly all H2B N-termini where acetylation is commonly expected. In addition, an unexpected modification on H2A histones was assigned to N-pyruvic acid 2-iminylation based on its unique neutral loss of CO2.
Project description:Sorghum is multipurpose crop worldwide serving as food, feed, and feedstock for biofuels, whose floral transition and vegetative growth heavily depend on photoperiod. Although multiple sorghum maturity loci (Ma1-Ma6) have been associated with photoperiod sensitivity in previous QTL studies, the underlying molecular mechanisms remain poorly understood. By functional characterizing sorghum SbGhd7 (Ma6) and integrating RNA-seq analysis of Ghd7 overexpression sorghum, ChIP-seq analysis of SbGhd7 binding sites in protoplasts and molecular studies, we discovered that SbEhd1 and SbFT10 are the direct targets of SbGhd7. SbGhd7 is a transcriptional repressor and inhibits florigen-induced floral transition by repressing SbEhd1 and SbFT10 expression.
Project description:To identify novel miRNA and NAT-siRNAs that are associated with abiotic stresses in sorghum, we generated small RNA sequences from sorghum seedlings that grew under control and under dought, salt, and cold stress treatments.
Project description:In this study, through computational modeling and synthetic biology tools, we identified and overcame a key flux controlling node in MEP-derived terpene biosynthesis in cyanobacteria. This strategy bypasses the limitation in traditional stepwise metabolic engineering, and led to significantly higher terpene productivity. Moreover, our results revealed photosynthesis limitations during high level of terpene production. We suggest that fine-tuning energy and reductant requirement could be a key factor in establishing a viable ‘non-native’ terpene sink in photosynthetic systems.
Project description:Vitis vinifera is widely grown worldwide for making wine and for use as table grapes. Of the existing cultivars, some have a floral and fruity flavour, referred to as a Muscat flavour. It is well-documented that this flavour originates from a series of terpene compounds, but the mechanism of terpene content differences among the Muscat-type cultivars remains unclear. Transcript and terpene metabolite profiles were integrated to elucidate the molecular mechanism of this phenomenon. In this research, three genotypes with different aromatic strengths were investigated by RNA sequencing. A total of 27 fruit samples from three biological replicates were sequenced on Illumina HiSeq 2000 at three stages, corresponding to the veraison; berries had intermediate Brix value and were harvest-ripe. After quality assessment and data clearance, a total of 254.18 Gb of data with more than 97% Q20 bases were obtained, approximately 9.41 Gb data were generated per sample. These results will provide a valuable dataset for the discovery of the mechanism of terpene biosynthesis.
Project description:This study compared the proteomic differences of rice sorghum GJH1 and rice sorghum BTx623 during seed development in order to reveal the specific proteins of rice sorghum seed development.
Project description:The proposed project aims to elucidate the gene-regulatory networks (GRNs) underlying terpenoid metabolism in three major bioenergy crops, switchgrass (Panicum virgatum), maize (Zea mays), and sorghum (Sorghum bicolor), to aid crop development for enhanced stress resilience and biofuel production from biomass feedstock. Prior studies identified more than 50 terpene synthases (TPS) and cytochrome P450 monooxygenases (P450), as key enzymes in generating bioactive terpenoids, in several bioenergy plants including switchgrass and maize. This knowledge now enables a precise investigation of the GRNs that govern common and species-specific terpenoid pathways. We will integrate transcription factor (TF) functional studies, TF binding site mapping, transcript and metabolite profiling, and terpenoid pathway engineering to identify the terpenoid-metabolic TF networks mediating stress responses in switchgrass, maize and sorghum.
The work (proposal:https://doi.org/10.46936/10.25585/60001378) conducted by the U.S. Department of Energy Joint Genome Institute (https://ror.org/04xm1d337), a DOE Office of Science User Facility, is supported by the Office of Science of the U.S. Department of Energy operated under Contract No. DE-AC02-05CH11231.
Project description:We sequenced three small-RNA (sRNA) libraries constructed from leaves of sorghum subjected to three different treatments, well-watered (CK), mild drought (DR1) and severe drought (DR2). These findings will be useful for research on drought resistance and provide insights into the mechanisms of drought adaptation and resistance in sorghum.