Pldα1-Knockdown Soybean Seeds Display Higher Unsaturated Glycerolipid Contents And Seed Vigor In High Temperature And Humidity Environments, Xuemin Wang, Gaoyang Zhang, Sung‑Chul Bahn, Geliang Wang, Yanrui Zhang, Beibei Chen, Yuliang Zhang, Jian Zhao
Jan 2019
Pldα1-Knockdown Soybean Seeds Display Higher Unsaturated Glycerolipid Contents And Seed Vigor In High Temperature And Humidity Environments, Xuemin Wang, Gaoyang Zhang, Sung‑Chul Bahn, Geliang Wang, Yanrui Zhang, Beibei Chen, Yuliang Zhang, Jian Zhao
Xuemin (Sam) Wang
Background
Soybean oil constitutes an important source of vegetable oil and biofuel. However, high temperature and humidity adversely impacts soybean seed development, yield, and quality during plant development and after harvest. Genetic improvement of soybean tolerance to stress environments is highly desirable.
Results
Transgenic soybean lines with knockdown of phospholipase Dα1 (PLDα1KD) were generated to study PLDα1′s effects on lipid metabolism and seed vigor under high temperature and humidity conditions. Under such stress, as compared with normal growth conditions, PLDα1KD lines showed an attenuated stress-induced deterioration during soybean seed development, which was associated with elevated expression of reactive oxygen species-scavenging …
Phospholipase Dζ Enhances Diacylglycerol Flux Into Triacylglycerol, Wenyu Yang, Geliang Wang, Jia Li, Philip David Bates, Xuemin Wang, Douglas K. Allen
Jan 2017
Phospholipase Dζ Enhances Diacylglycerol Flux Into Triacylglycerol, Wenyu Yang, Geliang Wang, Jia Li, Philip David Bates, Xuemin Wang, Douglas K. Allen
Xuemin (Sam) Wang
Plant seeds are the primary source of triacylglycerols (TAG) for food, feed, fuel, and industrial applications. As TAG is produced from diacylglycerol (DAG), successful engineering strategies to enhance TAG levels have focused on the conversion of DAG to TAG. However, the production of TAG can be limited by flux through the enzymatic reactions that supply DAG. In this study, two Arabidopsis phospholipase Dζ genes (AtPLDζ1 and AtPLDζ2) were coexpressed in Camelina sativa to test whether the conversion of phosphatidylcholine to DAG impacts TAG levels in seeds. The resulting transgenic plants produced 2% to 3% more TAG as a component of …
Non-Specific Phospholipase C1 Affects Silicon Distribution And Mechanical Strength In Stem Nodes Of Rice, Huasheng Cao, Lin Zhuo, Yuan Su, Linxiao Sun, Xuemin Wang
May 2016
Non-Specific Phospholipase C1 Affects Silicon Distribution And Mechanical Strength In Stem Nodes Of Rice, Huasheng Cao, Lin Zhuo, Yuan Su, Linxiao Sun, Xuemin Wang
Xuemin (Sam) Wang
Silicon, the second abundant element in the crust, is beneficial for plant growth, mechanical strength, and stress responses. Here we show that manipulation of the non‐specific phospholipase C1, NPC1, alters silicon content in nodes and husks of rice (Oryza sativa). Silicon content in NPC1‐overexpressing (OE) plants was decreased in nodes but increased in husks compared to wild‐type, whereas RNAi suppression of NPC1 resulted in the opposite changes to those of NPC1‐OE plants. NPC1 from rice hydrolyzed phospholipids and galactolipids to generate diacylglycerol that can be phosphorylated to phosphatidic acid. Phosphatidic acid interacts with Lsi6, a silicon transporter that is expressed …
Membrane Glycerolipidome Of Soybean Root Hairs And Its Response To Nitrogen And Phosphate Availability, Fang Wei, Brian Fanella, Liang Guo, Xuemin Wang
Jan 2016
Membrane Glycerolipidome Of Soybean Root Hairs And Its Response To Nitrogen And Phosphate Availability, Fang Wei, Brian Fanella, Liang Guo, Xuemin Wang
Xuemin (Sam) Wang
Root hairs are tubular extensions of specific root epidermal cells important in plant nutrition and water absorption. To determine membrane glycerolipids in root hairs and roots may differ, as well as their respective response to nutrient availability, this study analyzed the membrane glycerolipid species in soybean root hairs and in roots stripped of root hairs, and their response to nitrogen (N) and phosphate (Pi) supplementation. The ratio of phospholipids to galactolipids was 1.5 fold higher in root hairs than in stripped roots. Under Pi deficiency, the ratio of phospholipids to galactolipids in stripped roots decreased with the greatest decrease found …
Overexpression Of Patatin‐Related Phospholipase Aiiiδ Altered Plant Growth And Increased Seed Oil Content In Camelina, Xuemin Wang, Maoyin Li, Fang Wei, Amanda Tawfall, Michelle Tang, Allison Saettele
Jul 2015
Overexpression Of Patatin‐Related Phospholipase Aiiiδ Altered Plant Growth And Increased Seed Oil Content In Camelina, Xuemin Wang, Maoyin Li, Fang Wei, Amanda Tawfall, Michelle Tang, Allison Saettele
Xuemin (Sam) Wang
Camelina sativa is a Brassicaceae oilseed species being explored as a biofuel and industrial oil crop. A growing number of studies have indicated that the turnover of phosphatidylcholine plays an important role in the synthesis and modification of triacylglycerols. This study manipulated the expression of a patatin‐related phospholipase AIIIδ (pPLAIIIδ) in camelina to determine its effect on seed oil content and plant growth. Constitutive overexpression of pPLAIIIδ under the control of the constitutive cauliflower mosaic 35S promoter resulted in a significant increase in seed oil content and a decrease in cellulose content. In addition, the content of major membrane phospholipids, …
Comprehensive Quantification Of Triacylglycerols In Soybean Seeds By Electrospray Ionization Mass Spectrometry With Multiple Neutral Loss Scans, Maoyin Li, Emily Butka, Xuemin Wang
Apr 2015
Comprehensive Quantification Of Triacylglycerols In Soybean Seeds By Electrospray Ionization Mass Spectrometry With Multiple Neutral Loss Scans, Maoyin Li, Emily Butka, Xuemin Wang
Xuemin (Sam) Wang
Soybean seeds are an important source of vegetable oil and biomaterials. The content of individual triacylglycerol species (TAG) in soybean seeds is difficult to quantify in an accurate and rapid way. The present study establishes an approach to quantify TAG species in soybean seeds utilizing an electrospray ionization tandem mass spectrometry with multiple neutral loss scans. Ten neutral loss scans were performed to detect the fatty acyl chains of TAG, including palmitic (P, 16:0), linolenic (Ln, 18:3), linoleic (L, 18:2), oleic (O, 18:1), stearic (S, 18:0), eicosadienoic (20:2), gadoleic (20:1), arachidic (20:0), erucic (22:1), and behenic (22:0). The abundance of …
Role Of Aminoalcoholphosphotransferases 1 And 2 In Phospholipid Homeostasis In Arabidopsis, Xuemin Wang, Yu Liu, Geliang Wang
Apr 2015
Role Of Aminoalcoholphosphotransferases 1 And 2 In Phospholipid Homeostasis In Arabidopsis, Xuemin Wang, Yu Liu, Geliang Wang
Xuemin (Sam) Wang
Aminoalcoholphosphotransferase (AAPT) catalyzes the synthesis of phosphatidylcholine (PC) and phosphotidylethanolamine (PE), which are the most prevalent membrane phospholipids in all eukaryotic cells. Here, we show that suppression of AAPTs results in extensive membrane phospholipid remodeling in Arabidopsis thaliana. Double knockout (KO) mutants that are hemizygous for either aapt1 or aapt2 display impaired pollen and seed development, leading to embryotic lethality of the double KO plants, whereas aapt1 or aapt2 single KO plants show no overt phenotypic alterations. The growth rate and seed yield of AAPT RNA interference (RNAi) plants are greatly reduced. Lipid profiling shows decreased total galactolipid and phospholipid …
Identification Of Heat Responsive Genes In Brassica Napus Siliques At The Seed-Filling Stage Through Transcriptional Profiling, Xuemin Wang, Erru Yu, Chuchuan Fan, Qingyong Yang, Xiaodong Li, Bingxi Wan, Yanni Dong, Yongming Zhou
Jul 2014
Identification Of Heat Responsive Genes In Brassica Napus Siliques At The Seed-Filling Stage Through Transcriptional Profiling, Xuemin Wang, Erru Yu, Chuchuan Fan, Qingyong Yang, Xiaodong Li, Bingxi Wan, Yanni Dong, Yongming Zhou
Xuemin (Sam) Wang
High temperature stress results in yield loss and alterations to seed composition during seed filling in oilseed rape (Brassica napus). However, the mechanism underlying this heat response is poorly understood. In this study, global transcription profiles of 20 d-old siliques of B. napus were analyzed after heat stress using a Brassica 95k EST microarray. The up-regulated genes included many HSF/HSP transcripts and other heat-related marker genes, such as ROF2, DREB2a, MBF1c and Hsa32, reflecting the conservation of key heat resistance factors among plants. Other up-regulated genes were preferentially expressed in heat-stressed silique walls or seeds, including some transcription factors and …
Phosphatidic Acid Interacts With A Myb Transcription Factor And Regulates Its Nuclear Localization And Function In Arabidopsis, Xuemin Wang, Hongyan Yao, Geliang Wang, Liang Guo
Nov 2013
Phosphatidic Acid Interacts With A Myb Transcription Factor And Regulates Its Nuclear Localization And Function In Arabidopsis, Xuemin Wang, Hongyan Yao, Geliang Wang, Liang Guo
Xuemin (Sam) Wang
Phosphatidic acid (PA) has emerged as a class of cellular mediators involved in various cellular and physiological processes, but little is known about its mechanism of action. Here we show that PA interacts with WEREWOLF (WER), a R2R3 MYB transcription factor involved in root hair formation. The PA-interacting region is confined to the end of the R2 subdomain. The ablation of the PA binding motif has no effect on WER binding to DNA, but abolishes its nuclear localization and its function in regulating epidermal cell fate. Inhibition of PA production by phospholipase Dζ also suppresses WER’s nuclear localization, root hair …
Lipid Signaling In Plants, Xuemin Wang, Kent D. Chapman
Jun 2013
Lipid Signaling In Plants, Xuemin Wang, Kent D. Chapman
Xuemin (Sam) Wang
No abstract provided.
Patatin-Related Phospholipase Pplaiiiδ Increases Seed Oil Content With Long-Chain Fatty Acids In Arabidopsis, Xuemin Wang, Maoyin Li, Sung Chul Bahn, Chuchuan Fan, Jia Li, Tien Phan, Michael Ortiz, Mary R. Roth, Ruth Welti
Apr 2013
Patatin-Related Phospholipase Pplaiiiδ Increases Seed Oil Content With Long-Chain Fatty Acids In Arabidopsis, Xuemin Wang, Maoyin Li, Sung Chul Bahn, Chuchuan Fan, Jia Li, Tien Phan, Michael Ortiz, Mary R. Roth, Ruth Welti
Xuemin (Sam) Wang
The release of fatty acids from membrane lipids has been implicated in various metabolic and physiological processes, but in many cases, the enzymes involved and their functions in plants remain unclear. Patatin-related phospholipase As (pPLAs) constitute a major family of acyl-hydrolyzing enzymes in plants. Here, we show that pPLAIIIδ promotes the production of triacylglycerols with 20- and 22-carbon fatty acids in Arabidopsis (Arabidopsis thaliana). Of the four pPLAIIIs (α, β, γ, δ), only pPLAIIIδ gene knockout results in a decrease in seed oil content, and pPLAIIIδ is most highly expressed in developing embryos. The overexpression of pPLAIIIδ increases the content …
Phosphatidic Acid Binds To Cytosolic Glyceraldehyde-3-Phosphate Dehydrogenase And Promotes Its Cleavage In Arabidopsis, Xuemin Wang, Sang-Chul Kim, Liang Guo
Mar 2013
Phosphatidic Acid Binds To Cytosolic Glyceraldehyde-3-Phosphate Dehydrogenase And Promotes Its Cleavage In Arabidopsis, Xuemin Wang, Sang-Chul Kim, Liang Guo
Xuemin (Sam) Wang
Phosphatidic acid (PA) is a class of lipid messengers involved in a variety of physiological processes. To understand how PA mediates cell functions in plants, we used a PA affinity membrane assay to isolate PA-binding proteins from Camelina sativa followed by mass spectrometric sequencing. A cytosolic glyceraldehyde-3-phosphate dehydrogenase (GAPC) was identified to bind to PA, and detailed analysis was carried out subsequently using GAPC1 and GAPC1 from Arabidopsis. The PA and GAPC binding was abolished by the cation zinc whereas oxidation of GAPCs promoted the PA binding. PA had little impact on the GAPC catalytic activity in vitro, but the …
Cytosolic Glyceraldehyde-3-Phosphate Dehydrogenases Interact With Phospholipase Dδ To Transduce Hydrogen Peroxide Signals In The Arabidopsis Response To Stress, Xuemin Wang, Liang Guo, Shivakumar P. Devaiah, Rama Narasimhan, Xiangqing Pan, Yanyan Zhang, Wenhua Zhang
Apr 2012
Cytosolic Glyceraldehyde-3-Phosphate Dehydrogenases Interact With Phospholipase Dδ To Transduce Hydrogen Peroxide Signals In The Arabidopsis Response To Stress, Xuemin Wang, Liang Guo, Shivakumar P. Devaiah, Rama Narasimhan, Xiangqing Pan, Yanyan Zhang, Wenhua Zhang
Xuemin (Sam) Wang
Reactive oxygen species (ROS) are produced in plants under various stress conditions and serve as important mediators in plant responses to stresses. Here, we show that the cytosolic glycolytic enzymes glyceraldehyde-3-phosphate dehydrogenases (GAPCs) interact with the plasma membrane–associated phospholipase D (PLDδ) to transduce the ROS hydrogen peroxide (H2O2) signal in Arabidopsis thaliana. Genetic ablation of PLDδ impeded stomatal response to abscisic acid (ABA) and H2O2, placing PLDδ downstream of H2O2 in mediating ABA-induced stomatal closure. To determine the molecular link between H2O2 and PLDδ, GAPC1 and GAPC2 were identified to bind to PLDδ, and the interaction was demonstrated by coprecipitation …
Levels Of Arabidopsis Thaliana Leaf Phosphatidic Acids, Phosphatidylserines, And Most Trienoate-Containing Polar Lipid Molecular Species Increase During The Dark Period Of The Diurnal Cycle, Xuemin Wang, Sara Maatta, Brad Scheu, Mary R. Roth, Pamela Tamura, Maoyin Li, Todd D. Williams, Ruth Welti
Mar 2012
Levels Of Arabidopsis Thaliana Leaf Phosphatidic Acids, Phosphatidylserines, And Most Trienoate-Containing Polar Lipid Molecular Species Increase During The Dark Period Of The Diurnal Cycle, Xuemin Wang, Sara Maatta, Brad Scheu, Mary R. Roth, Pamela Tamura, Maoyin Li, Todd D. Williams, Ruth Welti
Xuemin (Sam) Wang
Previous work has demonstrated that plant leaf polar lipid fatty acid composition varies during the diurnal (dark–light) cycle. Fatty acid synthesis occurs primarily during the light, but fatty acid desaturation continues in the absence of light, resulting in polyunsaturated fatty acids reaching their highest levels toward the end of the dark period. In this work, Arabidopsis thaliana were grown at constant (21°C) temperature with 12-h light and 12-h dark periods. Collision induced dissociation time-of-flight mass spectrometry (MS) demonstrated that 16:3 and 18:3 fatty acid content in membrane lipids of leaves are higher at the end of the dark than at …
Direct Infusion Mass Spectrometry Of Oxylipin-Containing Arabidopsis Membrane Lipids Reveals Varied Patterns In Different Stress Responses, Xuemin Wang, Hieu Sy Vu, Pamela Tamura, Nadezhda A. Galeva, Ratnesh Chaturvedi, Mary R. Roth, Todd Williams, Jyoti Shah, Ruth Welti
Dec 2011
Direct Infusion Mass Spectrometry Of Oxylipin-Containing Arabidopsis Membrane Lipids Reveals Varied Patterns In Different Stress Responses, Xuemin Wang, Hieu Sy Vu, Pamela Tamura, Nadezhda A. Galeva, Ratnesh Chaturvedi, Mary R. Roth, Todd Williams, Jyoti Shah, Ruth Welti
Xuemin (Sam) Wang
Direct infusion electrospray ionization triple quadrupole precursor scanning for three oxidized fatty acyl anions revealed 86 mass spectral peaks representing polar membrane lipids in extracts from Arabidopsis (Arabidopsis thaliana) infected with Pseudomonas syringae pv tomato DC3000 expressing AvrRpt2 (PstAvr). Quadrupole time-of-flight and Fourier transform ion cyclotron resonance mass spectrometry provided evidence for the presence of membrane lipids containing one or more oxidized acyl chains. The membrane lipids included molecular species of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, digalactosyldiacylglycerol, monogalactosyldiacylglycerol, and acylated monogalactosyldiacylglycerol. The oxidized chains were identified at the level of chemical formula and included C(18)H(27)O(3) (abbreviated 18:4-O, to indicate four double bond …
Suppression Of Phospholipase Dγs Confers Increased Aluminum Resistance In Arabidopsis Thaliana, Xuemin Wang, Jian Zhao, Cunxi Wang, Mohamed Bedair, Ruth Welti, Lloyd W. Sumner, Ivan Baxter
Nov 2011
Suppression Of Phospholipase Dγs Confers Increased Aluminum Resistance In Arabidopsis Thaliana, Xuemin Wang, Jian Zhao, Cunxi Wang, Mohamed Bedair, Ruth Welti, Lloyd W. Sumner, Ivan Baxter
Xuemin (Sam) Wang
Aluminum (Al) toxicity is the major stress in acidic soil that comprises about 50% of the world's arable land. The complex molecular mechanisms of Al toxicity have yet to be fully determined. As a barrier to Al entrance, plant cell membranes play essential roles in plant interaction with Al, and lipid composition and membrane integrity change significantly under Al stress. Here, we show that phospholipase Dγs (PLDγs) are induced by Al stress and contribute to Al-induced membrane lipid alterations. RNAi suppression of PLDγ resulted in a decrease in both PLDγ1 and PLDγ2 expression and an increase in Al resistance. Genetic …
Phosphatidic Acid Binds And Stimulates Arabidopsis Sphingosine Kinases, Xuemin Wang, Liang Guo, Girish Mishra, Kyle Taylor
Apr 2011
Phosphatidic Acid Binds And Stimulates Arabidopsis Sphingosine Kinases, Xuemin Wang, Liang Guo, Girish Mishra, Kyle Taylor
Xuemin (Sam) Wang
Phosphatidic acid (PA) and phytosphingosine-1-phosphate (phyto-S1P) have both been identified as lipid messengers mediating plant response to abscisic acid (ABA). To determine the relationship of these messengers, we investigated the direct interaction of PA with Arabidopsis sphingosine kinases (SPHKs) that phosphorylate phytosphingosine to generate phyto-S1P. Two unique SPHK cDNAs were cloned from the annotated At4g21540 locus of Arabidopsis, and the two transcripts are differentially expressed in Arabidopsis tissues. Both SPHKs are catalytically active, phosphorylating various longchain sphingoid bases (LCBs) and are associated with the tonoplast. They both interact with PA as demonstrated by lipid-filter binding, liposome binding, and surface plasmon …
Patatin-Related Phospholipase Pplaiiiβ-Induced Changes In Lipid Metabolism Alter Cellulose Content And Cell Elongation In Arabidopsis, Xuemin Wang, Maoyin Li, Sung Chul Bahn, Liang Guo, William Musgrave, Howard Berg, Ruth Welti
Feb 2011
Patatin-Related Phospholipase Pplaiiiβ-Induced Changes In Lipid Metabolism Alter Cellulose Content And Cell Elongation In Arabidopsis, Xuemin Wang, Maoyin Li, Sung Chul Bahn, Liang Guo, William Musgrave, Howard Berg, Ruth Welti
Xuemin (Sam) Wang
The release of fatty acids from membrane lipids has been implicated in various plant processes, and the patatin-related phospholipases (pPLAs) constitute a major enzyme family that catalyzes fatty acid release. The Arabidopsis thaliana pPLA family has 10 members that are classified into three groups. Group 3 pPLAIII has four members but lacks the canonical lipase/esterase consensus catalytic sequences, and their enzymatic activity and cellular functions have not been delineated. Here, we show that pPLAIIIβ hydrolyzes phospholipids and galactolipids and additionally has acyl-CoA thioesterase activity. Alterations of pPLAIIIβ result in changes in lipid levels and composition. pPLAIIIβ-KO plants have longer leaves, …
Assaying Different Types Of Plant Phospholipase D Activities In Vitro, Xuemin Wang, Kirk L. Pappan
Dec 2010
Assaying Different Types Of Plant Phospholipase D Activities In Vitro, Xuemin Wang, Kirk L. Pappan
Xuemin (Sam) Wang
Over the past decade, tremendous progress has been made toward understanding the physiological functions of individual members of the diverse phospholipase D (PLD) family of enzymes in plants. For instance, the involvement of plant PLD members has been shown or suggested in a wide variety of the cellular and physiological processes such as regulating stomatal opening and closure; signaling plant responses to drought, salt, and other abiotic and biotic stresses; organizing microtubule and actin cytoskeletal structures; promoting pollen tube growth; cycling phosphorus; signaling nitrogen availability; regulating N-acylethanolamine stress signaling; and remodeling membrane phospholipids in plant responses to phosphate deprivation and …
Nonspecific Phospholipase C Npc4 Promotes Responses To Abscisic Acid And Tolerance To Hyperosmotic Stress In Arabidopsis, Xuemin Wang, Carlotta Peters, Maoyin Li, Rama Narasimhan, Mary Roth, Ruth Welti
Jun 2010
Nonspecific Phospholipase C Npc4 Promotes Responses To Abscisic Acid And Tolerance To Hyperosmotic Stress In Arabidopsis, Xuemin Wang, Carlotta Peters, Maoyin Li, Rama Narasimhan, Mary Roth, Ruth Welti
Xuemin (Sam) Wang
Diacyglycerol (DAG) is an important class of cellular lipid messengers, but its function in plants remains elusive. Here, we show that knockout of the Arabidopsis thaliana nonspecific phospholipase C (NPC4) results in a decrease in DAG levels and compromises plant response to abscisic acid (ABA) and hyperosmotic stresses. NPC4 hydrolyzes various phospholipids in a calcium-independent manner, producing DAG and a phosphorylated head group. NPC4 knockout (KO) plants display decreased ABA sensitivity in seed germination, root elongation, and stomatal movement and had decreased tolerance to high salinity and water deficiency. Overexpression of NPC4 renders plants more sensitive to ABA and more …
Phospholipase Dα1 And Phosphatidic Acid Regulate Nadph Oxidase Activity And Production Of Reactive Oxygen Species In Aba-Mediated Stomatal Closure In Arabidopsis, Xuemin Wang, Yanyan Zhang, Huiying Zhu, Qun Zhang, Maoyin Li, Min Yan, Rong Wang, Liling Wang, Ruth Welti, Wenhua Zhang
Jul 2009
Phospholipase Dα1 And Phosphatidic Acid Regulate Nadph Oxidase Activity And Production Of Reactive Oxygen Species In Aba-Mediated Stomatal Closure In Arabidopsis, Xuemin Wang, Yanyan Zhang, Huiying Zhu, Qun Zhang, Maoyin Li, Min Yan, Rong Wang, Liling Wang, Ruth Welti, Wenhua Zhang
Xuemin (Sam) Wang
We determined the role of Phospholipase Dα1 (PLDα1) and its lipid product phosphatidic acid (PA) in abscisic acid (ABA)-induced production of reactive oxygen species (ROS) in Arabidopsis thaliana guard cells. The pldα1 mutant failed to produce ROS in guard cells in response to ABA. ABA stimulated NADPH oxidase activity in wild-type guard cells but not in pldα1 cells, whereas PA stimulated NADPH oxidase activity in both genotypes. PA bound to recombinant Arabidopsis NADPH oxidase RbohD (respiratory burst oxidase homolog D) and RbohF. The PA binding motifs were identified, and mutation of the Arg residues 149, 150, 156, and 157 in …
Phospholipase Dα3 Is Involved In The Hyperosmotic Response In Arabidopsis, Xuemin Wang, Yueyun Hong, Xiangqing Pan, Ruth Welti
Feb 2008
Phospholipase Dα3 Is Involved In The Hyperosmotic Response In Arabidopsis, Xuemin Wang, Yueyun Hong, Xiangqing Pan, Ruth Welti
Xuemin (Sam) Wang
Rapid activation of phospholipase D (PLD), which hydrolyzes membrane lipids to generate phosphatidic acid (PA), occurs under various hyperosmotic conditions, including salinity and water deficiency. The Arabidopsis thaliana PLD family has 12 members, and the function of PLD activation in hyperosmotic stress responses has remained elusive. Here, we show that knockout (KO) and overexpression (OE) of previously uncharacterized PLDα3 alter plant response to salinity and water deficit. PLDα3 uses multiple phospholipids as substrates with distinguishable preferences, and alterations of PLDα3 result in changes in PA level and membrane lipid composition. PLDα3-KO plants display increased sensitivities to salinity and water deficiency …
Differential Degradation Of Extraplastidic And Plastidic Lipids During Freezing And Post-Freezing Recovery In Arabidopsis Thaliana, Xuemin Wang, Weiqi Li, Ruiping Wang, Maoyin Li, Lixia Li, Chuanming Wang, Ruth Welti
Jan 2008
Differential Degradation Of Extraplastidic And Plastidic Lipids During Freezing And Post-Freezing Recovery In Arabidopsis Thaliana, Xuemin Wang, Weiqi Li, Ruiping Wang, Maoyin Li, Lixia Li, Chuanming Wang, Ruth Welti
Xuemin (Sam) Wang
Changes in membrane lipid composition play important roles in plant adaptation to and survival after freezing. Plant response to cold and freezing involves three distinct phases: cold acclimation, freezing, and post-freezing recovery. Considerable progress has been made toward understanding lipid changes during cold acclimation and freezing, but little is known about lipid alteration during post-freezing recovery. We previously showed that phospholipase D (PLD) is involved in lipid hydrolysis and Arabidopsis thaliana freezing tolerance. This study was undertaken to determine how lipid species change during post-freezing recovery and to determine the effect of two PLDs, PLD#1;1 and PLD, on lipid changes …
Atplai Is An Acyl Hydrolase Involved In Basal Jasmonic Acid Production And Arabidopsis Resistance To Botrytis Cinerea, Xuemin Wang, Wenyu Yang, Shivakumar P. Devaiah, Xiangqing Pan, Giorgis Isaac, Ruth Welti
Jun 2007
Atplai Is An Acyl Hydrolase Involved In Basal Jasmonic Acid Production And Arabidopsis Resistance To Botrytis Cinerea, Xuemin Wang, Wenyu Yang, Shivakumar P. Devaiah, Xiangqing Pan, Giorgis Isaac, Ruth Welti
Xuemin (Sam) Wang
Intracellular phospholipase A2 (PLA2) plays an important role in regulating oxylipin biosynthesis in mammals, but the molecular and biochemical nature of intracellular PLA2 is not well understood in plants. Arabidopsis thaliana gene At1g61850 (AtPLAI) encodes a 140-kDa protein that is most similar to mammalian calcium-independent PLA2, and additionally contains leucine-rich repeats and Armadillo repeats. AtPLAI hydrolyzes phospholipids at both the sn-1 and sn-2 positions, but prefers galactolipids to phospholipids as substrates. Profiling of lipid species altered in response to the necrotrophic fungus Botrytis cinerea revealed decreases in the levels of phosphatidylglycerol and digalactosyldiacylglycerol, suggesting that hydrolysis of plastidic polar lipids …
Rapid Characterization Of The Fatty Acyl Composition Of Complex Lipids By Collision-Induced Dissociation Time-Of-Flight Mass Spectrometry, Xuemin Wang, Steven Wynn Esch, Pamela Tamura, Alexis A. Sparks, Mary R. Roth, Shivakumar P. Devaiah, Ernst Heinz, Todd D. Williams, Ruth Welti
Dec 2006
Rapid Characterization Of The Fatty Acyl Composition Of Complex Lipids By Collision-Induced Dissociation Time-Of-Flight Mass Spectrometry, Xuemin Wang, Steven Wynn Esch, Pamela Tamura, Alexis A. Sparks, Mary R. Roth, Shivakumar P. Devaiah, Ernst Heinz, Todd D. Williams, Ruth Welti
Xuemin (Sam) Wang
Profiling of leaf extracts from mutants of Arabidopsis with defects in lipid desaturation demonstrates the utility of collision-induced dissociation time-of-flight mass spectrometry (CID-TOF MS) for screening biological samples for fatty acid compositional alterations. CID-TOF MS uses the collision cell of a quadrupole time-of-flight mass spectrometer to simultaneously fragment all of the ions produced by an ionization source. Electrospray ionization CID-TOF MS in the negative mode can be used to analyze fatty acyl anions derived from complex lipids as well as free fatty acids. Although acyl anion yield is shown to be a function of the lipid class and the position …
Quantitative Profiling Of Arabidopsis Polar Glycerolipids In Response To Phosphorus Starvation. Roles Of Phospholipases Dζ1 And Dζ2 In Phosphatidylcholine Hydrolysis And Digalactosyldiacylglycerol Accumulation In Phosphorus-Starved Plants, Xuemin Wang, Maoyin Li, Ruth Welti
Sep 2006
Quantitative Profiling Of Arabidopsis Polar Glycerolipids In Response To Phosphorus Starvation. Roles Of Phospholipases Dζ1 And Dζ2 In Phosphatidylcholine Hydrolysis And Digalactosyldiacylglycerol Accumulation In Phosphorus-Starved Plants, Xuemin Wang, Maoyin Li, Ruth Welti
Xuemin (Sam) Wang
Phosphorus is an essential macronutrient that often limits plant growth and development. Under phosphorus-limited conditions, plants undergo substantial alterations in membrane lipid composition to cope with phosphorus deficiency. To characterize the changes in lipid species and to identify enzymes involved in plant response to phosphorus starvation, 140 molecular species of polar glycerolipids were quantitatively profiled in rosettes and roots of wild-type Arabidopsis (Arabidopsis thaliana) and phospholipase D knockout mutants pldζ1, pldζ2, and pldζ1pldζ2. In response to phosphorus starvation, the concentration of phospholipids was decreased and that of galactolipids was increased. Phospholipid lost in phosphorus-starved Arabidopsis rosettes was replaced by an …
Double Knockouts Of Phospholipases Dζ1 And Dζ2 In Arabidopsis Affect Root Elongation During Phosphate-Limited Growth But Do Not Affect Root Hair Patterning, Xuemin Wang, Maoyin Li, Chunbo Qin, Ruth Welti
Jan 2006
Double Knockouts Of Phospholipases Dζ1 And Dζ2 In Arabidopsis Affect Root Elongation During Phosphate-Limited Growth But Do Not Affect Root Hair Patterning, Xuemin Wang, Maoyin Li, Chunbo Qin, Ruth Welti
Xuemin (Sam) Wang
Root elongation and root hair formation are important in nutrient absorption. We found that two Arabidopsis (Arabidopsis thaliana) phospholipase Ds (PLDs), PLDζ1 and PLDζ2, were involved in root elongation during phosphate limitation. PLDζ1 and PLDζ2 are structurally different from the majority of plant PLDs by having phox and pleckstrin homology domains. Both PLDζs were expressed more in roots than in other tissues. It was reported previously that inducible suppression or inducible overexpression of PLDζ1 affected root hair patterning. However, gene knockouts of PLDζ1, PLDζ2, or the double knockout of PLDζ1 and PLDζ2 showed no effect on root hair formation. The …
Regulatory Functions Of Phospholipase D And Phosphatidic Acid In Plant Growth, Development, And Stress Responses, Xuemin Wang
Sep 2005
Regulatory Functions Of Phospholipase D And Phosphatidic Acid In Plant Growth, Development, And Stress Responses, Xuemin Wang
Xuemin (Sam) Wang
No abstract provided.
Evidence For And Characterization Of Ca2+ Binding To The Catalytic Region Of Arabidopsis Thaliana Phospholipase Dβ, Xuemin Wang
Nov 2004
Evidence For And Characterization Of Ca2+ Binding To The Catalytic Region Of Arabidopsis Thaliana Phospholipase Dβ, Xuemin Wang
Xuemin (Sam) Wang
Most types of plant phospholipase D (PLD) require Ca2+ for activity, but how Ca2+ affects PLD activity is not well understood. We reported previously that Ca2+ binds to the regulatory C2 domain that occurs in the N terminus of the Ca2+-requiring PLDs. Using Arabidopsis thaliana PLDβ and C2-deleted PLDβ (PLDβcat), we now show that Ca2+ also interacts with the catalytic regions of PLD. PLDβcat exhibited Ca2+-dependent activity, was much less active, and required a higher level of Ca2+ than the full-length PLDβ. Ca2+ binding of the proteins was stimulated by phospholipids; phosphatidylserine was the most effective among those tested. Scatchard …
