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Rebecca L. Hansen Hongqing Guo Yanhai Yin Young Jin Lee 《The Plant journal : for cell and molecular biology》2019,97(2):341-351
The FERONIA (FER) signaling pathway is known to have diverse roles in Arabidopsis thaliana, such as growth, reproduction, and defense, but how this receptor kinase is involved in various biological processes is not well established. In this work, we applied multiple mass spectrometry techniques to identify metabolites involved in the FER signaling pathway and to understand their biological roles. A direct infusion Fourier transform ion cyclotron resonance (FT‐ICR)‐MS approach was used for initial screening of wild‐type and feronia (fer) mutant plant extracts, and Arabidopsides were found to be significantly enriched in the mutant. As Arabidopsides are known to be induced by wounding, further experiments on wounded and non‐wounded leaf samples were carried out to investigate these oxylipins as well as related phytohormones using a quadrupole‐time‐of‐flight (Q‐TOF) MS by direct injection and LC‐MS/MS. In a root growth bioassay with Arabidopside A isolated from fer mutants, the wild‐type showed significant root growth inhibition compared with the fer mutant. Our results therefore implicated Arabidopsides, and Arabidopside A specifically, in FER functions and/or signaling. Finally, matrix‐assisted laser desorption/ionization MS imaging (MALDI‐MSI) was used to visualize the localization of Arabidopsides, and we confirmed that Arabidopsides are highly abundant at wounding sites in both wild‐type and fer mutant leaves. More significantly, five micron high‐spatial resolution MALDI‐MSI revealed that Arabidopsides are localized to the chloroplasts where many stress signaling molecules are made. 相似文献
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Noemi Ruiz‐Lopez Richard P. Haslam Sarah Usher Johnathan A. Napier Olga Sayanova 《Plant biotechnology journal》2015,13(9):1264-1275
The synthesis and accumulation of omega‐3 long‐chain polyunsaturated fatty acids in transgenic Camelina sativa is demonstrated using the so‐called alternative pathway. This aerobic pathway is found in a small number of taxonomically unrelated unicellular organisms and utilizes a C18 Δ9‐elongase to generate C20 PUFAs. Here, we evaluated four different combinations of seed‐specific transgene‐derived activities to systematically determine the potential of this pathway to direct the synthesis of eicosapentaenoic acid (EPA) in transgenic plants. The accumulation of EPA and the related omega‐3 LC‐PUFA eicosatetraenoic acid (ETA) was observed up to 26.4% of total seed fatty acids, of which ETA was 9.5%. Seed oils such as these not only represent an additional source of EPA, but also an entirely new source of the bona fide fish oil ETA. Detailed lipidomic analysis of the alternative pathway in Camelina revealed that the acyl‐substrate preferences of the different activities in the pathway can still generate a substrate‐dichotomy bottleneck, largely due to inefficient acyl‐exchange from phospholipids into the acyl‐CoA pool. However, significant levels of EPA and ETA were detected in the triacylglycerols of transgenic seeds, confirming the channelling of these fatty acids into this storage lipid. 相似文献
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Sharmilee Gnanapavan Peggy Ho Wendy Heywood Sam Jackson Donna Grant Khadija Rantell Geoff Keir Kevin Mills Lawrence Steinman Gavin Giovannoni 《Journal of neurochemistry》2013,125(5):766-773
Multiple sclerosis (MS) is a CNS disorder characterized by demyelination and neurodegeneration. Although hallmarks of recovery (remyelination and repair) have been documented in early MS, the regenerative capacity of the adult CNS per se remains uncertain with the wide held belief that it is either limited or non‐existent. The neural cell adhesion molecule (NCAM) is a cell adhesion molecule that has been widely implicated in axonal outgrowth, guidance and fasciculation. Here, we used in vitro and in vivo of MS to investigate the role of NCAM in disease progression. We show that in health NCAM levels decrease over time, but this occurs acutely after demyelination and remains reduced in chronic disease. Our findings suggest that depletion of NCAM is one of the factors associated with or possibly responsible for disease progression in MS. 相似文献
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Maoyin Li Ethan Baughman Mary R. Roth Xianlin Han Ruth Welti Xuemin Wang 《The Plant journal : for cell and molecular biology》2014,77(1):160-172
Plant triacylglycerols (TAGs), or vegetable oils, provide approximately 25% of dietary calories to humans and are becoming an increasingly important source of renewable bioenergy and industrial feedstocks. TAGs are assembled by multiple enzymes in the endoplasmic reticulum from building blocks that include an invariable glycerol backbone and variable fatty acyl chains. It remains a challenge to elucidate the mechanism of synthesis of hundreds of different TAG species in planta. One reason is the lack of an efficient analytical approach quantifying individual molecular species. Here we report a rapid and quantitative TAG profiling approach for Arabidopsis seeds based on electrospray ionization tandem mass spectrometry with direct infusion and multiple neutral loss scans. The levels of 93 TAG molecular species, identified by their acyl components, were determined in Arabidopsis seeds. Quantitative TAG pattern analyses revealed that the TAG assembly machinery preferentially produces TAGs with one elongated fatty acid. The importance of the selectivity in oil synthesis was consistent with an observation that an Arabidopsis mutant overexpressing a patatin‐like phospholipase had enhanced seed oil content with elongated fatty acids. This quantitative TAG profiling approach should facilitate investigations aimed at understanding the biochemical mechanisms of TAG metabolism in plants. 相似文献
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Fauland A Köfeler H Trötzmüller M Knopf A Hartler J Eberl A Chitraju C Lankmayr E Spener F 《Journal of lipid research》2011,52(12):2314-2322
This work aims to combine chromatographic retention, high mass resolution and accuracy, MS/MS spectra, and a package for automated identification and quantitation of lipid species in one platform for lipidomic analysis. The instrumental setup elaborated comprises reversed-phase HPLC coupled to a Fourier transform ion cyclotron resonance mass spectrometer (LTQ-FT), and Lipid Data Analyzer (LDA) software. Data analysis for lipid species quantification in this platform is based on retention time, mass resolution of 200,000, and mass accuracy below 2 ppm. In addition, automatically generated MS/MS spectra provide structural information at molecular level. This LC/MS technology allows analyzing complex biological samples in a quantitative manner as shown here paradigmatically for murine lipid droplets having a huge surplus of triacylglycerol species. Chromatographic preseparation of the bulk lipid class alleviates the problem of ion suppression of lipid species from other classes. Extension of 1D to 2D chromatography is possible, yet time consuming. The platform affords unambiguous detection of lipid species as low as 0.1‰ within major lipid classes. Taken together, a novel lipidomic LC/MS platform based on chromatographic retention, high mass resolution and accuracy, MS/MS analysis, and quantitation software enables analysis of complex samples as demonstrated for lipid droplets. 相似文献
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Laura S. Hildesheim
ystein H. Opedal W. Scott Armbruster Christophe Plabon 《Ecology and evolution》2019,9(24):14253-14260
Greater pollination intensity can enhance maternal plant fitness by increasing seed set and seed quality as a result of more intense pollen competition or enhanced genetic sampling. We tested experimentally these effects by varying the pollen load from a single pollen donor on stigmas of female flowers of Dalechampia scandens (Euphorbiaceae) and measuring the effects on seed number and seed mass. Seed set increased rapidly with pollen number at low to moderate pollen loads, and a maximum set of three seeds occurred with a mean pollen load of 19 pollen grains. We did not detect a trade‐off between the number of seeds and seed mass within a fruit. Seed mass increased with increasing pollen load, supporting the hypothesis of enhanced seed quality via increased pollen‐competition intensity or genetic sampling. These results suggest that maternal fitness increases with larger pollen loads, even when the fertilization success is already high. Our results further highlight the importance of high rates of pollen arrival onto stigmas, as mediated by reliable pollinators. Comparing the pollen‐to‐seed response curve obtained in this experiment with those observed in natural populations suggests that pollen limitation may be more severe in natural populations than predicted from greenhouse studies. These results also indicate that declines in pollinator abundance may decrease plant fitness through lowered seed quality before an effect on seed set is detected. 相似文献
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Ellen R. A. Thomas Santosh S. Atanur Penny J. Norsworthy Vesela Encheva Ambrosius P. Snijders Laurence Game Jana Vandrovcova Afshan Siddiq Mary Seed Anne K. Soutar Timothy J. Aitman 《Molecular Genetics & Genomic Medicine》2013,1(3):155-161
Patients with autosomal dominant hypercholesterolemia (ADH) have a high risk of developing cardiovascular disease that can be effectively treated using statin drugs. Molecular diagnosis and family cascade screening is recommended for early identification of individuals at risk, but up to 40% of families have no mutation detected in known genes. This study combined linkage analysis and exome sequencing to identify a novel variant in exon 3 of APOB (Arg50Trp). Mass spectrometry established that low‐density lipoprotein (LDL) containing Arg50Trp APOB accumulates in the circulation of affected individuals, suggesting defective hepatic uptake. Previously reported mutations in APOB causing ADH have been located in exon 26. This is the first report of a mutation outside this region causing this phenotype, therefore, more extensive screening of this large and highly polymorphic gene may be necessary in ADH families. This is now feasible due to the high capacity of recently available sequencing platforms. 相似文献
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Large seeds contain more stored resources, and seedlings germinating from large seeds generally cope better with environmental stresses such as shading, competition and thick litter layers, than seedlings germinating from small seeds. A pattern with small‐seeded species being associated with open habitats and large‐seeded species being associated with closed (shaded) habitats has been suggested and supported by comparative studies. However, few studies have assessed the intra‐specific relationship between seed size and recruitment, comparing plant communities differing in canopy cover. Here, seeds from four plant species commonly occurring in ecotones between open and closed habitats (Convallaria majalis, Frangula alnus, Prunus padus and Prunus spinosa) were weighed and sown individually (3200 seeds per species) in open and closed‐canopy sites, and seedling emergence and survival recorded over 3 years. Our results show a generally positive, albeit weak, relationship between seed size and recruitment. In only one of the species, C. majalis, was there an association between closed canopy habitat and a positive seed size effect on recruitment. We conclude that there is a weak selection gradient favouring larger seeds, but that this selection gradient is not clearly related to habitat. 相似文献
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Mark A Gillespie Elizabeth S Gold Stephen A Ramsey Irina Podolsky Alan Aderem Jeffrey A Ranish 《The EMBO journal》2015,34(9):1244-1258
LXR–cofactor complexes activate the gene expression program responsible for cholesterol efflux in macrophages. Inflammation antagonizes this program, resulting in foam cell formation and atherosclerosis; however, the molecular mechanisms underlying this antagonism remain to be fully elucidated. We use promoter enrichment‐quantitative mass spectrometry (PE‐QMS) to characterize the composition of gene regulatory complexes assembled at the promoter of the lipid transporter Abca1 following downregulation of its expression. We identify a subset of proteins that show LXR ligand‐ and binding‐dependent association with the Abca1 promoter and demonstrate they differentially control Abca1 expression. We determine that NCOA5 is linked to inflammatory Toll‐like receptor (TLR) signaling and establish that NCOA5 functions as an LXR corepressor to attenuate Abca1 expression. Importantly, TLR3–LXR signal crosstalk promotes recruitment of NCOA5 to the Abca1 promoter together with loss of RNA polymerase II and reduced cholesterol efflux. Together, these data significantly expand our knowledge of regulatory inputs impinging on the Abca1 promoter and indicate a central role for NCOA5 in mediating crosstalk between pro‐inflammatory and anti‐inflammatory pathways that results in repression of macrophage cholesterol efflux. 相似文献
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The analysis of intact and underivatised lipids in body fluids as well as in cell and tissue extracts is of utmost importance in the field of early diagnosis. Therefore, fast, reliable, and automated analytical methods are needed to detect known as well as unknown species. The combination of solid phase extraction, high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance spectroscopy are best at meeting this challenge. Herein, we show a workflow for the reliable analysis of individual components in phosphatidylethanolamine extracts. The limitations and advantages of the individual methods are discussed. 相似文献
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Sudesh Chhikara Hesham M. Abdullah Parisa Akbari Danny Schnell Om Parkash Dhankher 《Plant biotechnology journal》2018,16(5):1034-1045
Plant seed oil‐based liquid transportation fuels (i.e., biodiesel and green diesel) have tremendous potential as environmentally, economically and technologically feasible alternatives to petroleum‐derived fuels. Due to their nutritional and industrial importance, one of the major objectives is to increase the seed yield and oil production of oilseed crops via biotechnological approaches. Camelina sativa, an emerging oilseed crop, has been proposed as an ideal crop for biodiesel and bioproduct applications. Further increase in seed oil yield by increasing the flux of carbon from increased photosynthesis into triacylglycerol (TAG) synthesis will make this crop more profitable. To increase the oil yield, we engineered Camelina by co‐expressing the Arabidopsis thaliana (L.) Heynh. diacylglycerol acyltransferase1 (DGAT1) and a yeast cytosolic glycerol‐3‐phosphate dehydrogenase (GPD1) genes under the control of seed‐specific promoters. Plants co‐expressing DGAT1 and GPD1 exhibited up to 13% higher seed oil content and up to 52% increase in seed mass compared to wild‐type plants. Further, DGAT1‐ and GDP1‐co‐expressing lines showed significantly higher seed and oil yields on a dry weight basis than the wild‐type controls or plants expressing DGAT1 and GPD1 alone. The oil harvest index (g oil per g total dry matter) for DGTA1‐ and GPD1‐co‐expressing lines was almost twofold higher as compared to wild type and the lines expressing DGAT1 and GPD1 alone. Therefore, combining the overexpression of TAG biosynthetic genes, DGAT1 and GPD1, appears to be a positive strategy to achieve a synergistic effect on the flux through the TAG synthesis pathway, and thereby further increase the oil yield. 相似文献
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Multiple‐reaction monitoring for multiplex detection of three bacterial toxins using liquid chromatography‐tandem mass spectrometry 
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下载免费PDF全文 Clostridium perfringens epsilon toxin, staphylococcal enterotoxin B and shiga toxin are implicated in a number of diseases and food‐borne intoxications and are considered potential agents for bioterrorism and warfare. Artificially generated aerosol is the likely mode of delivery of these for nefarious uses, potentially capable of causing mass destruction to human and animal health by inhalation of toxic bioaerosol. Multiplex and unambiguous detection of these agents is of paramount importance for emergency response in a biothreat scenario and for food safety. Multiple‐reaction monitoring (MRM) assay for simultaneous monitoring of the three toxins is reported here using reverse‐phase high‐performance liquid chromatography–electrospray ionization‐tandem mass spectrometry. Three different peptides with two fragment ions each were considered for quantification and confirmation. One of the three MRM transitions from each toxin, which exhibited the best sensitivity, was selected for multiplexing of the assay. Simulating a biothreat scenario wherein the bioaerosol is collected in 10 ml of buffer, the multiplex assay was tested with blind samples with one or more of the three toxins even in the presence of interfering Escherichia coli lysate proteins. 相似文献
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Xiaojing Li Juanying Ye Hong Ma Pingli Lu 《The Plant journal : for cell and molecular biology》2018,93(1):142-154
Protein lysine acetylation (KAC) is a dynamic and reversible post‐translational modification that has important biological roles in many organisms. Although KAC has been shown to affect reproductive development and meiosis in yeast and animals, similar studies are largely lacking in flowering plants, especially proteome‐scale investigations for particular reproductive stages. Here, we report results from a proteomic investigation to detect the KAC status of the developing rice anthers near the time of meiosis (RAM), providing strong biochemical evidence for roles of many KAC‐affected proteins during anther development and meiosis in rice. We identified a total of 1354 KAC sites in 676 proteins. Among these, 421 acetylated proteins with 629 KAC sites are novel, greatly enriching our knowledge on KAC in flowering plants. Gene Ontology enrichment analysis showed chromatin silencing, protein folding, fatty acid biosynthetic process and response to stress to be over‐represented. In addition, certain potentially specific KAC motifs in RAM were detected. Importantly, 357 rice meiocyte proteins were acetylated; and four proteins genetically identified to be important for rice tapetum and pollen development were acetylated on 14 KAC sites in total. Furthermore, 47 putative secretory proteins were detected to exhibit acetylated status in RAM. Moreover, by comparing our lysine acetylome with the RAM phosphoproteome we obtained previously, we proposed a correlation between KAC and phosphorylation as a potential modulatory mechanism in rice RAM. This study provides the first global survey of KAC in plant reproductive development, making a promising starting point for further functional analysis of KAC during rice anther development and meiosis. 相似文献
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Geographic variation in seed traits within and among forty‐two species of Rhododendron (Ericaceae) on the Tibetan plateau: relationships with altitude,habitat, plant height,and phylogeny 下载免费PDF全文
下载免费PDF全文 Yongji Wang Jianjian Wang Liming Lai Lianhe Jiang Ping Zhuang Lehua Zhang Yuanrun Zheng Jerry M. Baskin Carol C. Baskin 《Ecology and evolution》2014,4(10):1913-1923
Seed mass and morphology are plant life history traits that influence seed dispersal ability, seeding establishment success, and population distribution pattern. Southeastern Tibet is a diversity center for Rhododendron species, which are distributed from a few hundred meters to 5500 m above sea level. We examined intra‐ and interspecific variation in seed mass and morphology in relation to altitude, habitat, plant height, and phylogeny. Seed mass decreased significantly with the increasing altitude and increased significantly with increasing plant height among populations of the same species. Seed mass differed significantly among species and subsections, but not among sections and subgenera. Seed length, width, surface area, and wing length were significantly negative correlated with altitude and significantly positive correlated with plant height. Further, these traits differed significantly among habitats and varied among species and subsection, but not among sections and subgenera. Species at low elevation had larger seeds with larger wings, and seeds became smaller and the wings of seeds tended to be smaller with the increasing altitude. Morphology of the seed varied from flat round to long cylindrical with increasing altitude. We suggest that seed mass and morphology have evolved as a result of both long‐term adaptation and constraints of the taxonomic group over their long evolutionary history. 相似文献