A5057972678- Plant Molecular Biology Research
- Plant nutrient uptake and metabolism
- Seed Germination and Physiology
- Lipid metabolism and biosynthesis
- Plant biochemistry and biosynthesis
- Photosynthetic Processes and Mechanisms
- Bioactive Natural Diterpenoids Research
- Light effects on plants
- Peroxisome Proliferator-Activated Receptors
- Microbial Natural Products and Biosynthesis
- Plant responses to water stress
- Plant Parasitism and Resistance
- Plant Reproductive Biology
- Metabolomics and Mass Spectrometry Studies
- Plant Stress Responses and Tolerance
- Plant tissue culture and regeneration
- Transgenic Plants and Applications
- Toxin Mechanisms and Immunotoxins
- Chromatography in Natural Products
- Biological Stains and Phytochemicals
- Synthetic Organic Chemistry Methods
- Mosquito-borne diseases and control
- Polysaccharides and Plant Cell Walls
- Plant Genetic and Mutation Studies
- Analytical Chemistry and Chromatography
University of York
2010-2022
University of North Texas
2022
Abstract Regulation of seed germination requires coordinate action by the embryo and surrounding endosperm. We used Arabidopsis thaliana to establish relative roles endosperm in control seedling establishment. previously showed that endospermic oil reserves are postgerminatively via gluconeogenesis fuel establishment lipid breakdown is repressed abscisic acid (ABA) but not tissues. Here, we use RNA amplification describe transcriptome compare hormone responses show responds both ABA...
Arabidopsis thaliana is used as a model system to study triacylglycerol (TAG) accumulation and seed germination in oilseeds. Here, we consider the partitioning of these lipid reserves between embryo endosperm tissues mature seed. The accumulates significant quantities storage lipid, this effectively catabolized upon germination. This differs composition from that has specific function during Removing wild-type seeds resulted reduction hypocotyl elongation dark, demonstrating role for...
Summary The tps1 mutant, which is disrupted in the TREHALOSE‐6‐PHOSPHATE SYNTHASE 1 gene, has been previously characterized as a recessive embryo lethal. embryos do not develop past late torpedo or early cotyledon stage. We report here that at ultrastructural, biochemical, and transcriptional levels exhibits many features typically associated with maturation phase. appearance of storage reserve transcripts organelles follows same temporal pattern wild‐type (WT) silique does accumulation...
Plant oils in the form of triacylglycerol (TAG) are used for food, industrial feedstock and biofuel manufacture. Although TAG is typically harvested from fruit or seeds oil crop species, plants can also accumulate small amounts leaves other vegetative tissues. Here we show that leaf levels be increased significantly (10-20 fold) by blocking fatty acid breakdown, particularly during extended dark treatments senescence model plant Arabidopsis. Generation a double mutant breakdown...
Trehalose and associated metabolites are part of the sugar signalling system in plants have profound effects on development. Disruption TREHALOSE 6-PHOSPHATE SYNTHASE (TPS1) gene Arabidopsis results delayed embryo growth, altered cell wall morphology carbon metabolism abortion at torpedo stage. Here we investigate role TPS1 post-embryonic development using two approaches. In first use seed-specific ABI3 promoter to drive cDNA during development, resulting rescue embryo-lethal tps1 phenotype....
Summary The Arabidopsis acyl‐CoA oxidase (ACX) family comprises isozymes with distinct fatty acid chain‐length specificities that together catalyse the first step of peroxisomal β ‐oxidation. We have isolated and characterized T‐DNA insertion mutants in medium to long‐chain ( ACX1 ) ACX2 oxidases, show corresponding endogenous activities are decreased mutants. Lipid catabolism during germination early post‐germinative growth was unaltered acx1‐1 mutant, but slightly delayed acx2‐1 3‐day‐old...
Abstract Triacylglycerol (TAG) levels and oil bodies persist in sucrose (Suc)-rescued Arabidopsis (Arabidopsis thaliana) seedlings disrupted seed catabolism. This study set out to establish if TAG as a metabolically inert pool when downstream catabolism is disrupted, or other mechanisms, such fatty acid (FA) recycling into are operating. We show that composition changes significantly Suc-rescued compared with found dry seeds, 18:2 18:3 accumulating. However, 20:1 FA not efficiently recycled...
Freshly matured seeds exhibit primary dormancy, which prevents germination until environmental conditions are favorable. The establishment of dormancy occurs during seed development and involves both genetic factors that impact on the ratio two antagonistic phytohormones: abscisic acid (ABA), promotes gibberellic acid, germination. Although our understanding breakage in mature is well advanced, relatively little known about mechanisms involved establishing maturation. We previously showed...
The Euphorbiaceae produce a diverse range of diterpenoids, many which have pharmacological activities. These diterpenoids include ingenol mebutate, is licensed for the treatment precancerous skin condition (actinic keratosis), and phorbol derivatives such as resiniferatoxin prostratin, are undergoing investigation severe pain HIV, respectively. Despite interest in these their biosynthesis poorly understood at present, with only characterized step being conversion geranylgeranyl pyrophosphate...
Significance Seeds sense environmental conditions, such as light quality, to regulate their germination. Light enriched in the far-red wavelength, under-the-canopy (shade), increases abscisic acid (ABA) and decreases gibberellin (GA) levels, phytohormones repressing promoting germination, respectively. We have discovered that MFT functions a key repressor of germination under conditions by modulating ABA GA responses.
Abstract This work describes the development and application of an on‐line liquid chromatography/mass spectrometry (LC/MS) method using hydrophilic interaction chromatography (HILIC) coupled to negative ion mode electrospray ionisation trap mass (ESI‐MS) for analysis highly polar carbohydrate‐related metabolites commonly found in plants, ranging from reducing non‐reducing sugars sugar alcohols phosphates. Using this method, separation detection a mixture eight authentic standard compounds...
The period following seedling emergence is a particularly vulnerable stage in the plant life cycle. In Arabidopsis thaliana, phytochrome-interacting factor (PIF) subgroup of basic-helix-loop-helix transcription factors has pivotal role regulating growth during this early phase, integrating environmental and hormonal signals. We previously showed that SPATULA (SPT), PIF homolog, regulates seed dormancy. article, we establish unlike PIFs, which mainly promote hypocotyl elongation, SPT potent...
Malate, along with potassium and chloride ions, is an important solute for maintaining turgor pressure during stomatal opening. Although malate exported from guard cells closure, there controversy as to whether also metabolised. We provide evidence that phosphoenolpyruvate carboxykinase (PEPCK), enzyme involved in metabolism gluconeogenesis, necessary full closure the dark. Analysis of Arabidopsis PCK1 gene promoter indicated this PEPCK isoform specifically expressed trichomes leaf....
We previously demonstrated that the oxylipin 12-oxo-phytodienoic acid (OPDA) acts along with abscisic to regulate seed germination in Arabidopsis thaliana, but mechanistic details of this synergistic interaction remain be elucidated.Here, we show OPDA through inhibition effects acid, acid-sensing ABI5 protein, and gibberellin-sensing RGL2 DELLA protein.We further demonstrate also another dormancy-promoting factor, MOTHER-OF-FT-AND-TFL1 (MFT).Both MFT positively feed back into pathway by...
To engineer Nicotiana benthamiana to produce novel diterpenoids, we first aimed increase production of the diterpenoid precursor geranylgeranyl pyrophosphate (GGPP) by up-regulation key genes non-mevalonate (MEP) pathway sourced from Arabidopsis thaliana. We used transient expression evaluate combinations eight MEP plus GGPP synthase and a Jatropha curcas casbene (JcCAS) identify an optimal combination for GGPP. AtDXS AtHDR together with AtGGPPS JcCAS gave 410% in compared alone. This was...
Summary The multifunctional protein (MFP) of peroxisomal β ‐oxidation catalyses four separate reactions, two which (2‐ trans enoyl‐CoA hydratase and l ‐3‐hydroxyacyl‐CoA dehydrogenase) are core activities required for the catabolism all fatty acids. We have isolated characterized five Arabidopsis thaliana mutants in MFP2 gene that is expressed predominantly germinating seeds. Seedlings mfp2 require an exogenous supply sucrose seedling establishment to occur. Analysis mfp2‐1 seedlings...
Abstract Phosphoenolpyruvate carboxykinase (PEPCK) catalyzes the conversion of oxaloacetate to phosphoenolpyruvate in gluconeogenic production sugars from storage oil germinating oilseeds. Here, we present results analysis on PEPCK antisense Arabidopsis plants with a range enzyme activities 20% 80% wild-type levels. There is direct correlation between activity and seedling establishment during early post-germinative growth, thus demonstrating absolute requirement gluconeogenesis this...
The plant family Euphorbiaceae are an abundant source of structurally complex diterpenoids, many which have reported anti-cancer, anti-HIV, and anti-inflammatory activities. Among these, ingenol-3-angelate (1a), isolated from Euphorbia peplus, has potent anti-tumour activity. Here we report the discovery characterization first genes linked to committed steps (1a) biosynthesis in peplus. We identified two genes, products catalyse addition angelyl-CoA (9a) ingenol (5) scaffold produce (1a)....
The Euphorbiaceae produce a wide variety of bioactive diterpenoids. These include the lathyranes, which have received much interest due to their ability inhibit ABC transporters responsible for loss efficacy many chemotherapy drugs. lathyranes are also intermediates in biosynthesis range other diterpenoids with potential applications treatment pain, HIV and cancer. We report here gene cluster from Jatropha curcas that contains genes required convert geranylgeranyl pyrophosphate into number...
Significance Euphorbia peplus , a member of the genus, is rich in jatrophane and ingenane diterpenoids. Using metabolomics-guided transcriptomic approach to gene candidate identification, we have discovered short-chain dehydrogenase involved production lathyrane jolkinol E. We developed virus-induced gene-silencing method that has allowed us demonstrate direct relationship between casbene polycyclic diterpenoids C acts as key branch point intermediate ingenanes jatrophanes. This work...