The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
John Browse - One of the best experts on this subject based on the ideXlab platform.
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WRINKLED1 Rescues Feedback Inhibition of Fatty Acid Synthesis in Hydroxylase-Expressing Seeds.
Plant Physiology, 2016Co-Authors: Neil D. Adhikari, Philip David Bates, John BrowseAbstract:Previous attempts at engineering Arabidopsis (Arabidopsis thaliana) to produce seed oils containing hydroxy Fatty Acids (HFA) have resulted in low yields of HFA compared with the native castor (Ricinus communis) plant and caused undesirable effects, including reduced total oil content. Recent studies have led to an understanding of problems involved in the accumulation of HFA in oils of transgenic plants, which include metabolic bottlenecks and a decrease in the rate of Fatty Acid Synthesis. Focusing on engineering the triacylglycerol assembly mechanisms led to modest increases in the HFA content of seed oil, but much room for improvement still remains. We hypothesized that engineering Fatty Acid Synthesis in the plastids to increase flux would facilitate enhanced total incorporation of Fatty Acids, including HFA, into seed oil. The transcription factor WRINKLED1 (WRI1) positively regulates the expression of genes involved in Fatty Acid Synthesis and controls seed oil levels. We overexpressed Arabidopsis WRI1 in seeds of a transgenic line expressing the castor Fatty Acid hydroxylase. The proportion of HFA in the oil, the total HFA per seed, and the total oil content of seeds increased to an average of 20.9%, 1.26 µg, and 32.2%, respectively, across five independent lines, compared with 17.6%, 0.83 µg, and 27.9%, respectively, for isogenic segregants. WRI1 and WRI1-regulated genes involved in Fatty Acid Synthesis were up-regulated, providing for a corresponding increase in the rate of Fatty Acid Synthesis.
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WRINKLED1 Rescues Feedback Inhibition of Fatty Acid Synthesis in Hydroxylase-Expressing Seeds of Arabidopsis
Plant Physiology, 2016Co-Authors: Neil Adhikari, Philip David Bates, John BrowseAbstract:Previous attempts at engineering Arabidopsis to produce seed oils containing hydroxy Fatty Acids (HFA) have resulted in low yields of HFA compared to the native castor plant and caused undesirable effects including reduced total oil content. Recent studies have led to an understanding of problems involved in accumulation of HFA in oils of transgenic plants, which include metabolic bottlenecks and a decrease in the rate of Fatty Acid Synthesis. Focusing on engineering the triacylglycerol assembly mechanisms led to modest increases in HFA content of seed oil, but much room for improvement still remains. We hypothesized that engineering Fatty Acid Synthesis in the plastids to increase flux would facilitate enhanced total incorporation of Fatty Acids (FA) including HFA into seed oil. The transcription factor WRINKLED1 (WRI1) positively regulates expression of genes involved in Fatty Acid Synthesis and controls seed oil levels. We overexpressed Arabidopsis WRI1 in seeds of a transgenic line expressing the castor Fatty Acid hydroxylase. The proportion of HFA in the oil, total HFA/seed and the total oil content of seeds increased to an average of 20.9%, 1.26 {micro}g, and 32.2% respectively across five independent lines, compared to 17.6%, 0.83 {micro}g, and 27.9%, respectively, for isogenic segregants. WRI1 and WRI1-regulated genes involved in Fatty Acid Synthesis were upregulated, providing for a corresponding increase in the rate of Fatty Acid Synthesis.
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Fatty Acid Synthesis is inhibited by inefficient utilization of unusual Fatty Acids for glycerolipid assembly
Proceedings of the National Academy of Sciences of the United States of America, 2014Co-Authors: John B. Ohlrogge, Jan G Jaworski, Philip D Bates, Sean R Johnson, Jia Li, John BrowseAbstract:Degradation of unusual Fatty Acids through β-oxidation within transgenic plants has long been hypothesized as a major factor limiting the production of industrially useful unusual Fatty Acids in seed oils. Arabidopsis seeds expressing the castor Fatty Acid hydroxylase accumulate hydroxylated Fatty Acids up to 17% of total Fatty Acids in seed triacylglycerols; however, total seed oil is also reduced up to 50%. Investigations into the cause of the reduced oil phenotype through in vivo [14C]acetate and [3H]2O metabolic labeling of developing seeds surprisingly revealed that the rate of de novo Fatty Acid Synthesis within the transgenic seeds was approximately half that of control seeds. RNAseq analysis indicated no changes in expression of Fatty Acid Synthesis genes in hydroxylase-expressing plants. However, differential [14C]acetate and [14C]malonate metabolic labeling of hydroxylase-expressing seeds indicated the in vivo acetyl–CoA carboxylase activity was reduced to approximately half that of control seeds. Therefore, the reduction of oil content in the transgenic seeds is consistent with reduced de novo Fatty Acid Synthesis in the plastid rather than Fatty Acid degradation. Intriguingly, the coexpression of triacylglycerol Synthesis isozymes from castor along with the Fatty Acid hydroxylase alleviated the reduced acetyl–CoA carboxylase activity, restored the rate of Fatty Acid Synthesis, and the accumulation of seed oil was substantially recovered. Together these results suggest a previously unidentified mechanism that detects inefficient utilization of unusual Fatty Acids within the endoplasmic reticulum and activates an endogenous pathway for posttranslational reduction of Fatty Acid Synthesis within the plastid.
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Is Acetylcarnitine a Substrate for Fatty Acid Synthesis in Plants
Plant Physiology, 1993Co-Authors: Grattan Roughan, John B. Ohlrogge, Dusty Post-beittenmiller, John BrowseAbstract:Long-chain Fatty Acid Synthesis from [1-14C]acetylcarnitine by chloroplasts isolated from spinach (Spinacia oleracea), pea (Pisum sativum), amaranthus (Amaranthus lividus), or maize (Zea mays) occurred at less than 2% of the rate of Fatty Acid Synthesis from [1-14C]acetate irrespective of the maturity of the leaves or whether the plastids were purified using sucrose or Percoll medium. [1-14C]-Acetylcarnitine was not significantly utilized by highly active chloroplasts rapidly prepared from pea and spinach using methods not involving density gradient centrifugation. [1-14C]Acetylcarnitine was recovered quantitatively from chloroplast incubations following 10 min in the light. Unlabeled acetyl-L-carnitine (0.4 mM) did not compete with [1-14C]acetate (0.2 mM) as a substrate for Fatty Acid Synthesis by any of the more than 70 chloroplast preparations tested in this study. Carnitine acetyltransferase activity was not detected in any chloroplast preparation and was present in whole leaf homogenates at about 0.1% of the level of acetyl-coenzyme A synthetase activity. When supplied to detached pea shoots and detached spinach, amaranthus, and maize leaves via the transpiration stream, 1 to 4% of the [1-14C]acetylcarnitine and 47 to 57% of the [1-14C]acetate taken up was incorporated into lipids. Most (78-82%) of the [1-14C]acetylcarnitine taken up was recovered intact. It is concluded that acetylcarnitine is not a major precursor for Fatty Acid Synthesis in plants.
Chang Ji Zheng - One of the best experts on this subject based on the ideXlab platform.
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Fatty Acid Synthesis is a target for antibacterial activity of unsaturated Fatty Acids
FEBS Letters, 2005Co-Authors: Chang Ji ZhengAbstract:Long-chain unsaturated Fatty Acids, such as linoleic Acid, show antibacterial activity and are the key ingredients of antimicrobial food additives and some antibacterial herbs. However, the precise mechanism for this antimicrobial activity remains unclear. We found that linoleic Acid inhibited bacterial enoyl-acyl carrier protein reductase (FabI), an essential component of bacterial Fatty Acid Synthesis, which has served as a promising target for antibacterial drugs. Additional unsaturated Fatty Acids including palmitoleic Acid, oleic Acid, linolenic Acid, and arachidonic Acid also exhibited the inhibition of FabI. However, neither the saturated form (stearic Acid) nor the methyl ester of linoleic Acid inhibited FabI. These FabI-inhibitory activities of various Fatty Acids and their derivatives very well correlated with the inhibition of Fatty Acid bioSynthesis using [14C] acetate incorporation assay, and importantly, also correlated with antibacterial activity. Furthermore, the supplementation with exogenous Fatty Acids reversed the antibacterial effect of linoleic Acid, which showing that it target Fatty Acid Synthesis. Our data demonstrate for the first time that the antibacterial action of unsaturated Fatty Acids is mediated by the inhibition of Fatty Acid Synthesis.
Philip D Bates - One of the best experts on this subject based on the ideXlab platform.
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Fatty Acid Synthesis is inhibited by inefficient utilization of unusual Fatty Acids for glycerolipid assembly
Proceedings of the National Academy of Sciences of the United States of America, 2014Co-Authors: John B. Ohlrogge, Jan G Jaworski, Philip D Bates, Sean R Johnson, Jia Li, John BrowseAbstract:Degradation of unusual Fatty Acids through β-oxidation within transgenic plants has long been hypothesized as a major factor limiting the production of industrially useful unusual Fatty Acids in seed oils. Arabidopsis seeds expressing the castor Fatty Acid hydroxylase accumulate hydroxylated Fatty Acids up to 17% of total Fatty Acids in seed triacylglycerols; however, total seed oil is also reduced up to 50%. Investigations into the cause of the reduced oil phenotype through in vivo [14C]acetate and [3H]2O metabolic labeling of developing seeds surprisingly revealed that the rate of de novo Fatty Acid Synthesis within the transgenic seeds was approximately half that of control seeds. RNAseq analysis indicated no changes in expression of Fatty Acid Synthesis genes in hydroxylase-expressing plants. However, differential [14C]acetate and [14C]malonate metabolic labeling of hydroxylase-expressing seeds indicated the in vivo acetyl–CoA carboxylase activity was reduced to approximately half that of control seeds. Therefore, the reduction of oil content in the transgenic seeds is consistent with reduced de novo Fatty Acid Synthesis in the plastid rather than Fatty Acid degradation. Intriguingly, the coexpression of triacylglycerol Synthesis isozymes from castor along with the Fatty Acid hydroxylase alleviated the reduced acetyl–CoA carboxylase activity, restored the rate of Fatty Acid Synthesis, and the accumulation of seed oil was substantially recovered. Together these results suggest a previously unidentified mechanism that detects inefficient utilization of unusual Fatty Acids within the endoplasmic reticulum and activates an endogenous pathway for posttranslational reduction of Fatty Acid Synthesis within the plastid.
Neil Adhikari - One of the best experts on this subject based on the ideXlab platform.
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WRINKLED1 Rescues Feedback Inhibition of Fatty Acid Synthesis in Hydroxylase-Expressing Seeds of Arabidopsis
Plant Physiology, 2016Co-Authors: Neil Adhikari, Philip David Bates, John BrowseAbstract:Previous attempts at engineering Arabidopsis to produce seed oils containing hydroxy Fatty Acids (HFA) have resulted in low yields of HFA compared to the native castor plant and caused undesirable effects including reduced total oil content. Recent studies have led to an understanding of problems involved in accumulation of HFA in oils of transgenic plants, which include metabolic bottlenecks and a decrease in the rate of Fatty Acid Synthesis. Focusing on engineering the triacylglycerol assembly mechanisms led to modest increases in HFA content of seed oil, but much room for improvement still remains. We hypothesized that engineering Fatty Acid Synthesis in the plastids to increase flux would facilitate enhanced total incorporation of Fatty Acids (FA) including HFA into seed oil. The transcription factor WRINKLED1 (WRI1) positively regulates expression of genes involved in Fatty Acid Synthesis and controls seed oil levels. We overexpressed Arabidopsis WRI1 in seeds of a transgenic line expressing the castor Fatty Acid hydroxylase. The proportion of HFA in the oil, total HFA/seed and the total oil content of seeds increased to an average of 20.9%, 1.26 {micro}g, and 32.2% respectively across five independent lines, compared to 17.6%, 0.83 {micro}g, and 27.9%, respectively, for isogenic segregants. WRI1 and WRI1-regulated genes involved in Fatty Acid Synthesis were upregulated, providing for a corresponding increase in the rate of Fatty Acid Synthesis.
Philip David Bates - One of the best experts on this subject based on the ideXlab platform.
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WRINKLED1 Rescues Feedback Inhibition of Fatty Acid Synthesis in Hydroxylase-Expressing Seeds.
Plant Physiology, 2016Co-Authors: Neil D. Adhikari, Philip David Bates, John BrowseAbstract:Previous attempts at engineering Arabidopsis (Arabidopsis thaliana) to produce seed oils containing hydroxy Fatty Acids (HFA) have resulted in low yields of HFA compared with the native castor (Ricinus communis) plant and caused undesirable effects, including reduced total oil content. Recent studies have led to an understanding of problems involved in the accumulation of HFA in oils of transgenic plants, which include metabolic bottlenecks and a decrease in the rate of Fatty Acid Synthesis. Focusing on engineering the triacylglycerol assembly mechanisms led to modest increases in the HFA content of seed oil, but much room for improvement still remains. We hypothesized that engineering Fatty Acid Synthesis in the plastids to increase flux would facilitate enhanced total incorporation of Fatty Acids, including HFA, into seed oil. The transcription factor WRINKLED1 (WRI1) positively regulates the expression of genes involved in Fatty Acid Synthesis and controls seed oil levels. We overexpressed Arabidopsis WRI1 in seeds of a transgenic line expressing the castor Fatty Acid hydroxylase. The proportion of HFA in the oil, the total HFA per seed, and the total oil content of seeds increased to an average of 20.9%, 1.26 µg, and 32.2%, respectively, across five independent lines, compared with 17.6%, 0.83 µg, and 27.9%, respectively, for isogenic segregants. WRI1 and WRI1-regulated genes involved in Fatty Acid Synthesis were up-regulated, providing for a corresponding increase in the rate of Fatty Acid Synthesis.
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WRINKLED1 Rescues Feedback Inhibition of Fatty Acid Synthesis in Hydroxylase-Expressing Seeds of Arabidopsis
Plant Physiology, 2016Co-Authors: Neil Adhikari, Philip David Bates, John BrowseAbstract:Previous attempts at engineering Arabidopsis to produce seed oils containing hydroxy Fatty Acids (HFA) have resulted in low yields of HFA compared to the native castor plant and caused undesirable effects including reduced total oil content. Recent studies have led to an understanding of problems involved in accumulation of HFA in oils of transgenic plants, which include metabolic bottlenecks and a decrease in the rate of Fatty Acid Synthesis. Focusing on engineering the triacylglycerol assembly mechanisms led to modest increases in HFA content of seed oil, but much room for improvement still remains. We hypothesized that engineering Fatty Acid Synthesis in the plastids to increase flux would facilitate enhanced total incorporation of Fatty Acids (FA) including HFA into seed oil. The transcription factor WRINKLED1 (WRI1) positively regulates expression of genes involved in Fatty Acid Synthesis and controls seed oil levels. We overexpressed Arabidopsis WRI1 in seeds of a transgenic line expressing the castor Fatty Acid hydroxylase. The proportion of HFA in the oil, total HFA/seed and the total oil content of seeds increased to an average of 20.9%, 1.26 {micro}g, and 32.2% respectively across five independent lines, compared to 17.6%, 0.83 {micro}g, and 27.9%, respectively, for isogenic segregants. WRI1 and WRI1-regulated genes involved in Fatty Acid Synthesis were upregulated, providing for a corresponding increase in the rate of Fatty Acid Synthesis.
