Project description:Plant damage promotes the interaction of lipoxygenases (LOX) with fatty acids yielding 9-hydroperoxides, 13-hydroperoxides and complex arrays of oxylipins. The action of 13-LOX on linolenic acid enables production of 12-oxo-phytodienoic acid (12-OPDA) and its downstream products, termed jasmonates. As signals, jasmonates have related yet distinct roles in the regulation of plant resistance against insect and pathogen attack. A similar pathway involving 9-LOX activity on linolenic and linoleic acid leads to the 12-OPDA positional isomer, 10-oxo-11-phytodienoic acid (10-OPDA) and 10-oxo-11-phytoenoic acid (10-OPEA), respectively; however, physiological roles for 9-LOX cyclopentenones have remained unclear. In developing maize (Zea mays) leaves, southern leaf blight (Cochliobolus heterostrophus) infection results in dying necrotic tissue and the localized accumulation of 10-OPEA, 10-OPDA and a series of related 14- and 12-carbon metabolites, collectively termed ‘death acids’. 10-OPEA accumulation becomes wound-inducible within fungal-infected tissues and at physiologically relevant concentrations acts as a phytoalexin by suppressing the growth of fungi and herbivores including Aspergillus flavus, Fusarium verticillioides, and Helicoverpa zea. Unlike previously established maize phytoalexins, 10-OPEA and 10-OPDA display significant phytotoxicity. Both 12-OPDA and 10-OPEA promote the transcription of defense genes encoding glutathione S-transferases, cytochrome P450s, and pathogenesis-related proteins. In contrast, 10-OPEA only weakly promotes the accumulation of multiple protease inhibitor transcripts. Consistent with a role in dying tissue, 10-OPEA application promotes cysteine protease activation and cell death which is inhibited by overexpression of the cysteine protease inhibitor maize cystatin-9. Functions for 10-OPEA and associated death acids are consistent with specialized roles in local defense reactions.
Project description:Plant damage promotes the interaction of lipoxygenases (LOX) with fatty acids yielding 9-hydroperoxides, 13-hydroperoxides and complex arrays of oxylipins. The action of 13-LOX on linolenic acid enables production of 12-oxo-phytodienoic acid (12-OPDA) and its downstream products, termed jasmonates. As signals, jasmonates have related yet distinct roles in the regulation of plant resistance against insect and pathogen attack. A similar pathway involving 9-LOX activity on linolenic and linoleic acid leads to the 12-OPDA positional isomer, 10-oxo-11-phytodienoic acid (10-OPDA) and 10-oxo-11-phytoenoic acid (10-OPEA), respectively; however, physiological roles for 9-LOX cyclopentenones have remained unclear. In developing maize (Zea mays) leaves, southern leaf blight (Cochliobolus heterostrophus) infection results in dying necrotic tissue and the localized accumulation of 10-OPEA, 10-OPDA and a series of related 14- and 12-carbon metabolites, collectively termed ‘death acids’. 10-OPEA accumulation becomes wound-inducible within fungal-infected tissues and at physiologically relevant concentrations acts as a phytoalexin by suppressing the growth of fungi and herbivores including Aspergillus flavus, Fusarium verticillioides, and Helicoverpa zea. Unlike previously established maize phytoalexins, 10-OPEA and 10-OPDA display significant phytotoxicity. Both 12-OPDA and 10-OPEA promote the transcription of defense genes encoding glutathione S-transferases, cytochrome P450s, and pathogenesis-related proteins. In contrast, 10-OPEA only weakly promotes the accumulation of multiple protease inhibitor transcripts. Consistent with a role in dying tissue, 10-OPEA application promotes cysteine protease activation and cell death which is inhibited by overexpression of the cysteine protease inhibitor maize cystatin-9. Functions for 10-OPEA and associated death acids are consistent with specialized roles in local defense reactions. A total of 6 samples were analyzed, comprised of two treatments: 10-OPEA and DMSO carrier control (5%DMSO/0.1% Tween20 in H20), both in replicates of three.
Project description:Trans-10, Cis-12 conjugated linoleic acid (t10c12 CLA) causes fat loss in mouse 3T3-L1 adipocyte tissue culture; however cis-9, trans-11 CLA does not (this series). The early transcriptome changes were analyzed using high-density microarrays to better characterize the signaling pathways responding to c9t11 CLA. Their gene expression responses between 8 to 12 hr after treatment showed no gene expression changes indicative of an integrated stress response (ISR). Keywords: control/treatment time course
Project description:ChIP-Seq analysis revealed that suberoylanilidehydroxamic acid (SAHA) increases genome-wide H4 acetylation in differentially regulated genes, except for the 500 bp upstream of transcription start sites (TSS). Chromatin immunoprecipitation (ChIP) with massively parallel high throughput sequencing (Seq) was used to map genome-wide histone H4 acetylation (K4/7/11/15) in the presence or absence of SAHA in differentiating MC3T3 sc4 osteoblasts.
Project description:Opaque2 (O2) is a transcription factor that plays important roles during maize endosperm development. Mutation of the O2 gene improves the nutritional value of maize seeds, but also confers pleiotropic effects that result in reduced agronomic quality. To reveal the transcriptional regulatory framework of O2, we determined O2 DNA binding targets using chromatin immunoprecipitation coupled to high-throughput sequencing (ChIP-Seq). ChIP-Seq analysis detected 1,686 O2 DNA binding sites distributed over 1,143 genes. We identified 4 new O2 binding motifs; among them, TGACGTGG appears to be the most conserved and strongest. We confirmed that, except for the 16 kD and 18 kD zeins, O2 directly regulates expression of all other zeins. O2 directly regulates two transcription factors, genes linked to carbon and amino acid metabolism and abiotic stress resistance. Examination of 15 days after pollination(DAP) wild type maize endosperm with O2 specific antibody and IgG serves as control.
Project description:we used two contrasting maize genotypes with differential oil accumulation percentage. High oil content (HOC) maize had 11% oil content while low oil content (LOC) maize had significantly lower oil content (5.4%). Transmission electron microscopy revealed a higher accumulation of oil bodies in the HOC maize embryo as compared to LOC maize. Comparative RNA-sequencing analysis at different developmental stages of seed embryo identified 739 genes that are constantly differentially expressed (DEGs) at all the six developmental stages from 15 days after pollination (DAP) to 40 DAP. KEGG enrichment analysis identified fatty acid metabolism and fatty acid biosynthesis as the most enriched biological pathways contributed by these DEGs. Notably, transcriptional changes are more intense at the early stages of embryo development as compared to later stages. In addition, pathways related to oil biosynthesis and their corresponding genes were more enriched at 30 DAP, which seems to be the key stage for oil accumulation. The study also identified 33 key DEGs involved in fatty acid and triacylglycerols biosynthesis, most of them were up-regulated in HOC, which may shape the differential oil contents in the two contrasting maize. Notably, we uncovered that both acyl-CoA-dependent and acyl-CoA-independent processes are essential for the high oil accumulation in maize embryo.
Project description:After comparing albinism rate, T3 treatment and control larvae of 42 DAH were chosen for next high-throughput sequencing analyses of miRNA. A total of 337 miRNAs were identified via miRNA-seq and 12 miRNAs exhibited significantly differential expression patterns in D42_T3 vs D42_Con (TPM > 10, fold change ≥ 1.5 or ≤ 0.67 and q ≤ 0.05). These differentially expressed miRNAs targeted 3658 putative genes, further enriching 10 GO terms (q < 0.05).
Project description:P1 encodes an R2R3-MYB transcription factor responsible for the accumulation of insecticidal flavones in maize silks and red phlobaphene pigments in pericarps and other floral tissues, which contributed to making P1 an important visual marker since the dawn of modern genetics. We conducted RNA-Seq using from maize silks obtained at 2-3 days after emergence. High-throughput sequencing using the Illumina platform resulted in the generation of ~14 million high quality reads, corresponding to ~7 million reads for each sample, from which 76% aligned to the maize genome. Examination of two different RNA samples from maize silks obtained at 2-3 days after emergence
Project description:Plant cellular damage promotes the interaction of lipoxygenases (LOX) with free fatty acids to yield 9- and 13-hydroperoxides which are further metabolized into diverse oxylipins. The enzymatic action of 13-LOX on linolenic acid enables production of 12-oxo-phytodienoic acid (12-OPDA) and its downstream products, jointly known as jasmonates. As signals, jasmonates have related yet distinct roles in the regulation of plant resistance against insect and pathogen attack. An additional and conceptually parallel pathway involving 9-LOX activity on linoleic acid leads to the production of 10-oxo-11-phytoenoic acid (10-OPEA). Despite structural similarity to jasmonates, physiological roles for 10-OPEA have remained unclear. Both 12-OPDA and 10-OPEA equally promote the transcription of numerous defense genes encoding glutathione S-transferases, cytochrome P450s, and pathogenesis-related proteins; however, 10-OPEA activity diverges in the context of reduced protease inhibitor transcript accumulation. To identify additional differential responses, we subsequently performed whole transcriptome analyses using RNAseq. These comparisons provide a platform for further examination of plant response specificity to the cyclopentenone 10-OPEA.