Academic literature on the topic 'Plant proteins'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Plant proteins.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Plant proteins"
1
Chakraborty, Biswanath. "Plant Defense Proteins." NBU Journal of Plant Sciences 2, no. 1 (2008): 1–12. http://dx.doi.org/10.55734/nbujps.2007.v02i01.001.
Full textAbstract:
Plants are compelled to withstand stresses of all kinds, be it biotic, abiotic or anthropogenic as a consequence of their immobility. The initial infection process involving adhesion/recognition events between plants and fungal pathogens is essential for the establishment of pathogenesis. The extracellular matrix (ECM) is a biologically active part of the cell surface composed of a complex mixture of macromolecules that, in addition to serving a structural function, profoundly affect the cellular physiology of the organism. During the past two decades it has become evident that the cell wall is a dynamic organization that is essential for cell division, enlargement and differentiation as well as responding to biotic and abiotic stress. ECM is also the source of signals for cell recognition within the same or between different organisms. Cell walls are natural composite structures, mostly made up of high molecular weight polysaccharides, proteins and lignins. Lignins are only found in specific cell types. Arabidopsis thaliana cell wall proteins (CWP) that can be involved in modifications of cell wall components, wall structure and signaling as well as interactions with plasma membrane proteins at the cell surface has been reviewed.
2
Shewry, P. R. "Plant Storage Proteins." Biological Reviews 70, no. 3 (August 1995): 375–426. http://dx.doi.org/10.1111/j.1469-185x.1995.tb01195.x.
Full text
3
Graumann, Katja, and David E. Evans. "Plant SUN domain proteins." Plant Signaling & Behavior 5, no. 2 (February 2010): 154–56. http://dx.doi.org/10.4161/psb.5.2.10458.
Full text
4
Cassab, Gladys I. "PLANT CELL WALL PROTEINS." Annual Review of Plant Physiology and Plant Molecular Biology 49, no. 1 (June 1998): 281–309. http://dx.doi.org/10.1146/annurev.arplant.49.1.281.
Full text
5
Vercesi, Aníbal Eugênio, Jiri Borecký, Ivan de Godoy Maia, Paulo Arruda, Iolanda Midea Cuccovia, and Hernan Chaimovich. "PLANT UNCOUPLING MITOCHONDRIAL PROTEINS." Annual Review of Plant Biology 57, no. 1 (June 2006): 383–404. http://dx.doi.org/10.1146/annurev.arplant.57.032905.105335.
Full text
6
Grimes, Howard D., and R. William Breidenbach. "Plant Plasma Membrane Proteins." Plant Physiology 85, no. 4 (December 1, 1987): 1048–54. http://dx.doi.org/10.1104/pp.85.4.1048.
Full text
7
Grimes, Howard D., Raymond M. Slay, and Thomas K. Hodges. "Plant Plasma Membrane Proteins." Plant Physiology 88, no. 2 (October 1, 1988): 444–49. http://dx.doi.org/10.1104/pp.88.2.444.
Full text
8
Kandasamy, Muthugapatti K., Roger B. Deal, Elizabeth C. McKinney, and Richard B. Meagher. "Plant actin-related proteins." Trends in Plant Science 9, no. 4 (April 2004): 196–202. http://dx.doi.org/10.1016/j.tplants.2004.02.004.
Full text
9
Kaas, Quentin, and David J. Craik. "NMR of plant proteins." Progress in Nuclear Magnetic Resonance Spectroscopy 71 (May 2013): 1–34. http://dx.doi.org/10.1016/j.pnmrs.2013.01.003.
Full text
10
Deom, C. Michael, Moshe Lapidot, and Roger N. Beachy. "Plant virus movement proteins." Cell 69, no. 2 (April 1992): 221–24. http://dx.doi.org/10.1016/0092-8674(92)90403-y.
Full textDissertations / Theses on the topic "Plant proteins"
1
Wang, Anita Wen Tao. "Loss of lysine in plant foods." Thesis, The University of Sydney, 2004. https://hdl.handle.net/2123/27713.
Full textAbstract:
Humans obtain approximately 70% of their dietary protein from plant sources on a
global basis. In developing countries, vegetable protein intake is higher than in
developed countries (Lusas and Rhee, 1986). Cereals, pulses and oilseeds are not
only very important plant foods in the human diet, but also the main components of
feeds for livestock, which can be considered as source of dairy products and meat
for humans (Lasztity and Hidvegi, 1983). Cereals contribute the major dietary
source of carbohydrates, and a substantive source of protein, vitamins, and
minerals. Oilseeds are one of the main sources of lipid, and pulses supply protein
and / or lipid. In many countries, including developed and developing countries,
wheat products are consumed as a major component of the diet. Wheat flour is one
of the most important foods in many countries in the world. Wheat grain contains
6-20% protein, 63-77% starch, approximately 2% fat, 2.0-2.7% crude fiber and
1.4-2.0% ash, depending in part on variety and class, and on environmental
conditions during growth (Pomeranz, 1988). In many Asian countries, rice is the
main cereal in the diet.
2
Hansson, Maria. "Molecular characterization of protein phosphorylation in plant photosynthetic membranes." Doctoral thesis, Linköping : Linköping University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6665.
Full text
3
Sheth, Mili. "Discovery and characterization of KNOX proteins lacking a homeodomain, produced by alternative splicing of KNAT1-like genes in gymnosperms and angiosperms." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/31639.
Full text
4
Youn, Buhyun. "Structural studies of plant secoisolariciresinol dehydrogenase, plant vacuolar sorting receptor and reduction potential of rubredoxin." Online access for everyone, 2004. http://www.dissertations.wsu.edu/Dissertations/Fall2004/b%5Fyoun%5F120804.pdf.
Full text
5
Kwan, Ann H. Y. "Protein design based on a PHD scaffold." Connect to full text, 2004. http://setis.library.usyd.edu.au/adt/public_html/adt-NU/public/adt-NU20041202.102526/index.html.
Full textAbstract:
Thesis (Ph. D.)--School of Molecular and Microbial Biosciences, Faculty of Science, University of Sydney, 2004.Chapter headings on separately inserted unnumbered cream coloured leaves. Bibliography: leaves 122-135.
6
Crooks, Kim Chantelle. "Turnover of plant plasma membrane proteins." Thesis, Oxford Brookes University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363720.
Full text
7
Byass, Louise Jane. "Characterization of plant anti-freeze proteins." Thesis, University of York, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310913.
Full text
8
Mostafa, Kamel Abdelfatah Ali. "Interactions of food proteins with plant phenolics – modulation of structural, techno- and bio-functional properties of proteins." Phd thesis, Universität Potsdam, 2013. http://opus.kobv.de/ubp/volltexte/2013/6903/.
Full textAbstract:
The phenolic compounds as food components represent the largest group of secondary metabolites in plant foods. The phenolic compounds, e.g. chlorogenic acid (CQA), are susceptible to oxidation by enzymes specially, polyphenol oxidase (PPO) and at alkaline conditions. Both enzymatic and non-enzymatic oxidations occur in the presence of oxygen and produce quinone, which normally further react with other quinone to produce colored compounds (dimers), as well as is capable of undergoing a nucleophilic addition to proteins. The interactions of proteins with the phenolic compounds have received considerable attention in the recent years where, plant phenolic compounds have drawn increasing attention due to their antioxidant properties and their noticeable effects in the prevention of various oxidative stress associated diseases. Green coffee beans are one of the richest sources of chlorogenic acids. Therefore, a green coffee extract would provide an eligible food relevant source for phenolic compounds for modification of proteins.
The interaction between 5-CQA and amino acid lysine showed decrease in both free CQA and amino acid groups and only a slight effect on the antioxidative capacity depending on the reaction time was found. Furthermore, this interaction showed a large number of intermediary substances of low intensities. The reaction of lysine with 5-CQA in a model system initially leads to formation of 3-CQA and 4-CQA (both are isomers of 5-CQA), oxidation giving rise to the formation of a dimer which subsequently forms an adduct with lysine to finally result in a benzacridine derivative as reported and confirmed with the aid of HPLC coupled with ESI-MSn. The benzacridine derivative containing a trihydroxy structural element, was found to be yellow, being very reactive with oxygen yielding semiquinone and quinone type of products with characteristic green colors. Finally, the optimal conditions for this interaction as assessed by both the loss of CQA and free amino groups of lysine can be given at pH 7 and 25°C, the interaction increasing with incubation time and depending also on the amount of tyrosinase present. Green coffee bean has a higher diversity and content of phenolics, where besides the CQA isomers and their esters, other conjugates like feruloylquinic acids were also identified, thus documenting differences in phenolic profiles for the two coffee types (Coffea arabica and Coffea robusta). Coffee proteins are modified by interactions with phenolic compounds during the extraction, where those from C. arabica are more susceptible to these interactions compared to C. robusta, and the polyphenol oxidase activity seems to be a crucial factor for the formation of these addition products. Moreover, In-gel digestion combined with MALDI-TOF-MS revealed that the most reactive and susceptible protein fractions to covalent reactions are the α-chains of the 11S storage protein. Thus, based on these results and those supplied by other research groups, a tentative list of possible adduct structures was derived. The diversity of the different CQA derivatives present in green coffee beans complicates the series of reactions occurring, providing a broad palette of reaction products. These interactions influence the properties of protein, where they exposed changes in the solubility and hydrophobicity of proteins compared to faba bean proteins (as control).
Modification of milk whey protein products (primarily b-lactoglobulin) with coffee specific phenolics and commercial CQA under enzymatic and alkaline conditions seems to be affecting their chemical, structural and functional properties, where both modifications led to reduced free amino-,thiol groups and tryptophan content. We propose that the disulfide-thiol exchange in the C-terminus of b-lactoglobulin may be initiated by the redox conditions provided in the presence of CQA. The protein structure b-lactoglobulin thereupon becomes more disordered as simulated by molecular dynamic calculation. This unfolding process may additionally be supported by the reaction of the CQA at the proposed sites of modification of -amino groups of lysine (K77, K91, K138, K47) and the thiol group of cysteine (C121). These covalent modifications also decreased the solubility and hydrophobicity of b-lactoglobulin, moreover they provide modified protein samples with a high antioxidative power, thermally more stable as reflected by a higher Td, require less amount of energy to unfold and when emulsified with lutein esters, exhibit their higher stability against UV light. The MALDI-TOF and SDS-PAGE results revealed that proteins treated at alkaline conditions were more strongly modified than those treated under enzymatic conditions. Finally, the results showed a slight change in emulsifying properties of modified proteins.Für die Verbesserung von Nahrungsmitteleigenschaften können Modifikationen an verschiedenen Inhaltsstoffen vorgenommen werden. Beispielsweise werden bereits Proteine miteinander verknüpft und bilden sogenannte „Crosslinks“ oder vernetzte Biomoleküle. Diese werden für die Herstellung fester, viskoelastischer Produkte, die zum Verdicken als auch zum Stabilisieren von Emulsionen oder Schäumen eingesetzt werden, genutzt. Da die Verbraucher sich Zunehmens mit gesundheitsfördernden Lebensmitteln befassen, ist das Einbringen von gesundheitsfördernden Inhaltsstoffen wie z.B. phenolische Verbindungen, immer mehr in den Fokus der Forschung gerückt. Demnach ist das wissenschaftliche Bestreben phenolische Verbindungen in die Vernetzung von Proteinen mit einzubeziehen und deren positive Wirkungen (antioxidativ) auszunutzen, vorteilhaft. Als Phenole werden Verbindungen bezeichnet, die eine oder mehrere Hydroxygruppen am Benzolring aufweisen. Phenole liegen in der Enolform vor, da diese, bedingt durch den Erhalt des aromatischen Benzolringes, energetisch begünstigt ist. Kaffeesäure ist eine Hydroxyzimtsäure und in Kaffeebohnen zu finden. Der am häufigsten anzutreffende Ester besteht aus Kaffee- und Chinasäure. Der einfachste Vertreter ist die Chlorogensäure (5-Caffeoylchinasäure, 5-CQA), die in vielen Pflanzenteilen enthalten ist. Chlorogensäure und ihre Derivate besitzen ebenfalls antioxidative Eigenschaften. Zusätzlich wirken sie auf Enzyme, die an entzündlichen- oder allergischen Reaktion teilnehmen, inhibierend. Während Verarbeitungs- und Lagerungsprozessen können phenolische Komponenten pflanzlicher Lebensmittel mit den Aminosäuren der Proteine in Lebensmitteln reagieren. Solche Reaktionen können die physikalisch-chemischen Eigenschaften von Proteinen verändern und deren ernährungsphysiologische Wertigkeit vermindern. Proteine weisen verschiedene reaktive Seitengruppen (Sulfhydryl-, Hydroxyl-, Aminogruppen) auf, mit denen sie über kovalente und nicht-kovalente Wechselwirkungen mit Phenolen Verbindungen eingehen können. Zu den nicht-kovalenten Verbindungen gehören u. a. Wasserstoffbrückenbindungen, hydrophobe Wechselwirkungen und Ionenbindungen. Phenole (z.B. Chlorogensäuren) können bei Anwesenheit von Sauerstoff enzymatisch bzw. nichtenzymatisch oxidiert werden. Die Reaktionsprodukte (Chinone) bilden anschließend mit reaktiven Thiol- bzw. Aminogruppen von Proteinen Addukte. Die Erfassung dieser verschiedenen Facetten von Interaktionen stellt somit die primäre Forschungsaufgabe im Rahmen dieser Arbeit. Die primäre Aufgabe der vorliegenden Arbeit besteht demzufolge in der Etablierung der Analysen- und der Charakterisierungsmöglichkeiten solcher Wechselwirkungen (Bindung) pflanzlicher Verbindungen bzw. deren Reaktionsprodukten mit Proteinen u.a. über massenspektrometrische Methoden. Da die Wechselwirkung mit Proteinen auch zu Veränderungen der Proteinstruktur führt, können deren funktionelle Eigenschaften auch verändert sein. Dies soll anhand der Messung von isolierten Proteinen die an der Wechselwirkung beteiligt sind, nachgewiesen werden. Anschließend sollen über Docking-Untersuchungen die entsprechenden Bindungsstellen näher charakterisiert werden. Durch die vorliegenden Ergebnisse wurden mögliche Reaktionen von phenolischen Verbindungen mit Proteinen, näher charakterisiert. Es wurde festgestellt, dass die Apfelsorte Braeburn über die höchste PPO- Enzymaktivität beim gleichzeitigen niedrigen CQA Gehalt im Vergleich zu den anderen untersuchten Sorten verfügt. Die PPO/Tyrosinase modulierte Reaktionen zwischen CQA und Lysine wurden in Abhängigkeit der vorherrschenden Bedingungen optimiert und die Reaktionsprodukte analysiert. In dem zweiten Teil wurden solche Reaktionsmöglichkeiten in den Grünen Kaffeebohnen lokalisierte und modelliert. Dazu wurden die sortenabhängige CQA-Zusammensetzung ermittelt und die möglichen Reaktionen mit den Hauptspeicherproteinen des Kaffees dargestellt. Im letzten Teil wurden dann diese Reaktionen mit Molkenproteinen simuliert und Einflüsse auf die Struktur und die funktionellen Eigenschaften erfasst. Die Ergebnisse belegen eine umfangreiche und sehr heterogene Adduktbildung mit den Aminoseitenketten des Lysins und Cysteins. Ein Katalog der unterschiedlichen Reaktionsprodukte wurde erstellt und am Protein modelliert. Die entsprechende Veränderung an die Proteinstruktur wurde experimentell belegt und der Einfluss wurde in den technofunktionelle Eigenschaften (wie die Löslichkeit, Emulgierbarkeit usw.) wiederspiegelt. Ein Anstieg des antioxidativen Potentials der Proteine wurde erreicht und diese so modifizierten Proteine wurden weiter zur Stabilisierung und Produktentwicklung getestet. Die ersten Ergebnisse eröffnen Nutzungsmöglichkeiten der modifizierten Proteine zur Verkapselung von bioaktiven Sekundären Pflanzenstoffen.
9
Johansson, Monika. "The role of nucleoside diphosphate kinase in plant mitochondria /." Uppsala : Dept. of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, 2006. http://epsilon.slu.se/200674.pdf.
Full text
10
Mahe, Laetitia. "Import of chimeric proteins into plant mitochondria." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33804.
Full textAbstract:
Cytoplasmic male sterility (CMS) in plants is associated with mitochondrial dysfunction. We have proposed in this study that the mitochondrial-encoded chimeric peptide thought to be responsible for cytoplasmic male sterility in Polima system could function as a dominant male sterility inducer when expressed in the nucleus and targeted to the mitochondria. Transgenic plants expressing such mitochondrial targeting constructs exhibited reduction of pollen production that was characterized in fertile Westar (nap ) and restored fertile Westar (pol) plants by homeotic transformation of floral organs and in male-sterile Westar (pol) plants by a reduction in pollen production with shortening of the stamens. Genetic and molecular analysis has shown that the phenotypic changes were correlated with the effective genetic transmission of the inserted transgene through female gametes. Most significantly, we have found that differences in floral morphology induced by transgene expression between pol CMS and fertile Westar plants might be related to differences in transcriptional activity of the APETALA3 MADS box gene. We suggest that the alterations in floral morphology that accompany CMS in several plant species might be due to effects of mitochondria on transcriptional activity of floral organ identity genes.
Books on the topic "Plant proteins"
1
Lord, Mike, and Martin R. Hartley. Toxic plant proteins. Heidelberg: Springer, 2010.
Find full text
2
R, Shewry P., and Gutteridge S, eds. Plant protein engineering. Cambridge, Eng: Cambridge University Press, 1992.
Find full text
3
Lord, J. Michael, and Martin R. Hartley, eds. Toxic Plant Proteins. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-12176-0.
Full text
4
Carbonell, Alberto, ed. Plant Argonaute Proteins. New York, NY: Springer New York, 2017. http://dx.doi.org/10.1007/978-1-4939-7165-7.
Full text
5
Christine, Finnie, ed. Plant proteomics. Oxford, UK: Blackwell Pub., 2006.
Find full text
6
Jozef, Šamaj, and Thelen Jay J, eds. Plant proteomics. Berlin: Springer, 2007.
Find full text
7
Shewry, Peter R. Seed Proteins. Dordrecht: Springer Netherlands, 1999.
Find full text
8
Guéguen, Jacques, and Yves Popineau, eds. Plant Proteins from European Crops. Berlin, Heidelberg: Springer Berlin Heidelberg, 1998. http://dx.doi.org/10.1007/978-3-662-03720-1.
Full text
9
M, Kreis, and Walker J. C, eds. Plant protein kinases. San Diego: Academic Press, 2000.
Find full text
10
K, Datta S., and Muthukrishnan Subbaratnam, eds. Pathogenesis-related proteins in plants. Boca Raton: CRC Press, 1999.
Find full textBook chapters on the topic "Plant proteins"
1
Riley, William W. "Plant Proteins." In Alternative Proteins, 17–47. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9780429299834-2.
Full text
2
Vaclavik, Vickie A., Marcia H. Pimentel, and Marjorie M. Devine. "Plant Proteins." In Dimensions of Food, 127–38. Boston, MA: Springer US, 1998. http://dx.doi.org/10.1007/978-1-4615-6859-9_11.
Full text
3
Egbert, William Russell, and C. Tony Payne. "Plant Proteins." In Ingredients in Meat Products, 111–29. New York, NY: Springer New York, 2009. http://dx.doi.org/10.1007/978-0-387-71327-4_5.
Full text
4
Leshem, Ya’Acov Y. "Membrane proteins." In Plant Membranes, 65–102. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-017-2683-2_5.
Full text
5
Buntru, Matthias, Simon Vogel, Ricarda Finnern, and Stefan Schillberg. "Plant-Based Cell-Free Transcription and Translation of Recombinant Proteins." In Recombinant Proteins in Plants, 113–24. New York, NY: Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2241-4_8.
Full textAbstract:
AbstractPlant cell-free lysates contain all the cellular components of the protein biosynthesis machinery, providing an alternative to intact plant cells, tissues, and whole plants for the production of recombinant proteins. Cell-free lysates achieve rapid protein production (within hours or days) and allow the synthesis of proteins that are cytotoxic or unstable in living cells. The open nature of cell-free lysates and their homogeneous and reproducible performance is ideal for protein production, especially for screening applications, allowing the direct addition of nucleic acid templates encoding proteins of interest, as well as other components such as enzyme substrates, chaperones, artificial amino acids, or labeling molecules. Here we describe procedures for the production of recombinant proteins in the ALiCE (Almost Living Cell-free Expression) system, a lysate derived from tobacco cell suspension cultures that can be used to manufacture protein products for molecular and biochemical analysis as well as applications in the pharmaceutical industry.
6
Fischer, Rainer, Richard M. Twyman, Jürgen Drossard, Stephan Hellwig, and Stefan Schillberg. "Plant Cells." In Production of Recombinant Proteins, 253–72. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2005. http://dx.doi.org/10.1002/3527603670.ch12.
Full text
7
Yun, Dae-Jin, Ray A. Bressan, and Paul M. Hasegawa. "Plant Antifungal Proteins." In Plant Breeding Reviews, 39–88. Oxford, UK: John Wiley & Sons, Inc., 2010. http://dx.doi.org/10.1002/9780470650073.ch3.
Full text
8
Wisniewski, Michael, Ian R. Willick, John G. Duman, David Livingston, and Samuel S. Newton. "Plant Antifreeze Proteins." In Antifreeze Proteins Volume 1, 189–226. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-41929-5_7.
Full text
9
Peumans, Willy J., and Els J. M. Van Damme. "Evolution of Plant Ribosome-Inactivating Proteins." In Toxic Plant Proteins, 1–26. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-12176-0_1.
Full text
10
Frigerio, Lorenzo, and Lynne M. Roberts. "The Synthesis of Ricinus communis Lectins." In Toxic Plant Proteins, 191–205. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-12176-0_10.
Full textConference papers on the topic "Plant proteins"
1
Lamsal, Buddhi, and Bibek Byanju. "Processing opportunities and challenges for plant-based proteins." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/cjmp7212.
Full textAbstract:
With demand for nutritious and functional protein-rich ingredients rising, there are opportunities to acquire protein from new/ emerging sources, as well as from coproducts of agro-food industry. Some of these sources include plants/ seeds and oilseeds, microalgae, fungi, cell/ microbial, and insect protein; however, each of these may have their own unique challenges in terms of extraction, nutritional profile, bioactivity, techno-functional properties, safety, allergenicity as well as in food and feed applications. Some of the challenges for plant/seed proteins are that they have relatively lower extraction yields and relatively inferior functional/ nutritional aspects, including off-flavor and digestibility. Protein quality in defatted meals is also impacted by harsh oil removal process, which is further exacerbated by the downstream protein extraction and isolation conditions (pH, ionic strength, temperature etc.) resulting in protein denaturation, aggregation, and potential loss of functionality. Also, plant proteins have other issues such as off-flavors, astringency/ taste, allergenicity, and antinutritional factors that reduce mineral bioavailability and protein absorption. Various food processing techniques can be used to reduce/ remove these aspects of protein ingredients; fermentation, germination, heating, enzymatic, or acidic treatment, membrane separation etc. have been employed to improve protein purity and quality. The choice of processing technology, even for oil removal from oilseed, impacts protein extraction and quality. For example, protein recovered from meal/ fibers of aqueous oil extraction were of better quality than from desolventized meals. Emerging physical and biochemical processes, such as high-power sonication, extrusion, high-pressure processing, microwave, pulsed electric field, enzymatic pretreatment (pectinase, proteinase, carbohydrase), and fermentation are reported to increase protein extraction efficiency, removing/ reducing allergenicity, and modify functional characteristics. This presentation will discuss such processing challenges and opportunities for plant-based proteins for extraction and downstream isolation, as well as their impact on important functional characteristics.
2
Munch, Katharina, Claire Berton-Carabin, Karin Schroen, and Simeon Stoyanov. "Plant protein-stabilized emulsions: Implications of protein and non-protein components for lipid oxidation." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/zznf4565.
Full textAbstract:
The use of plant proteins to stabilize oil-in-water (O/W) emulsions has been an increasing trend lately. The complexity of the available plant protein ingredients, along with the proteins’ physicochemical properties, require advanced processing that typically leads to substantial concentrations of non-protein components in the final isolates or concentrates. It is known that those components, such as polyphenols, phytic acid or phospholipids, can have a strong influence on the oxidative stability of emulsions. Thus, to understand the oxidative stability of plant protein-stabilized emulsions, the influence of the non-protein components also needs to be considered. Many food emulsions, such as mayonnaise or infant formula, are stabilized by not only proteins, but also phospholipids. Such an interfacial protein-phospholipid combination can also be found in oleosomes, natural lipid droplets which show a high oxidative stability. This stability has been attributed to their interfacial architecture in which oleosins and phospholipids form a tight physical barrier against pro-oxidant species. However, while the antioxidant properties of proteins are widely reported, the contribution of phospholipids to lipid oxidation in plant protein-based emulsions remains underexplored.
In this work, we investigated how mixed interfacial plant proteins and phospholipids may be rationally used to control the oxidative stability of O/W emulsions. The interfacial composition was modulated by varying the ratio between pea proteins and sunflower phosphatidylcholine (PC) while keeping the total concentration of pea proteins constant. Increasing the phospholipid-to-protein ratio led to a monotonic decrease in the concentration of proteins and an increase of phospholipids at the interface, while the oxidative stability of those O/W emulsions changed in a non-monotonic pattern. The results were put in perspective by embedding them in a context of reviewing the potential implications of typical components in plant protein ingredients on lipid oxidation.
3
Lozovskaya, V. S. "THE USE OF ALTERNATIVE PROTEIN SOURCES IN THE FOOD INDUSTRY: PROSPECTS FOR PLANT AND CELLULAR PROTEINS." In STATE AND DEVELOPMENT PROSPECTS OF AGRIBUSINESS. ООО «ДГТУ-Принт» Адрес полиграфического предприятия: 344003, г. Ростов-на-Дону, пл. Гагарина,1., 2024. http://dx.doi.org/10.23947/interagro.2024.279-282.
Full textAbstract:
The discussion of the use of alternative protein sources in the food industry, including plant and cellular proteins, is a significant topic in the modern context. The use of alternative protein sources in the food industry is relevant in light of the increased interest in plant and cellular proteins. These sources represent promising alternatives to animal proteins in the food industry. Vegetable proteins can be obtained from various plants such as beans, peas, soybeans, nuts and cereals, which allows you to diversify and enrich food products. Cellular proteins produced using cell culture technologies also represent a promising source of protein for the food industry. The prospects for the use of plant and cellular proteins include improving the environmental sustainability of food production, reducing dependence on animal protein sources, as well as enriching the nutritional value of products.
4
Tirtom, Sena, and Aslı Akpınar. "Dairy Protein vs. Plant Protein and Their Consumer Perception." In 7th International Students Science Congress. Izmir International guest Students Association, 2023. http://dx.doi.org/10.52460/issc.2023.026.
Full textAbstract:
Proteins are crucial macronutrient for human health. Animal, dairy, and some plant proteins are considered high-quality proteins that provide health and metabolic benefits based on the digestible levels of essential amino acids they contain. Animal protein is rich in many essential amino acids, but excessive animal protein intake greatly increases fat intake. Therefore, due to the improvement in people's living standards and increase in protein intake, the animal protein supply is not sufficient to meet the increasing demand of people. Technologically, milk proteins are the most important component of milk due to their unique properties that allow milk to be converted into a wide range of products such as cheese or yoghurt quite easily. It is widely accepted that dairy products are excellent sources of highly digestible essential amino acids. Nowadays, plant protein is preferred because has advantages such as it is an abundant source, cheap, easy to obtain, preferred by special consumer groups such as vegan/vegetarian, does not contain cholesterol and preventing diseases. In the last decades, the increasing interest of both producers and consumers in plant proteins and the decrease in animal protein intake and inclination to plant protein intake with the innovations in the markets emphasize the importance of these alternative sources. In this review, information is given about the importance of milk proteins and plant proteins and the role they play in consumer preference is mentioned.
5
Luo, Fei, Ondrej Halgas, Pratish Gawand, and Sagar Lahiri. "Animal-free protein production using precision fermentation." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/ntka8679.
Full textAbstract:
The $1.4 trillion animal industry could not sustainably scale further to feed the next billion population, as it is resource intensive, and heavy in greenhouse gas emission. The recent plant-based food movement has provided solution for more sustainable protein sources. However, the plant-based food sector faces challenges in reaching parity in texture, sensory experience (mouthfeel) and nutritional value as animal products, limiting their potential of reaching beyond the vegan and flexitarian consumers. The technical challenge behind this problem is that proteins from plants have intrinsically different amino acid compositions and structures from animal proteins, making it challenging to emulate the properties of animal products using plant-proteins alone. There is a clear and underserved need for novel protein ingredients that can complement plant-based protein ingredients to achieve parity of animal products. Fermentation is considered the third pillar of alternative protein revolution. At Liven, we focus our efforts on developing precision fermentation technology to produce functional protein ingredients that are natural replica of animal proteins. Using engineering biology, we transforms microorganisms with genes that are responsible for producing animal proteins such as collagen and gelatin. The transformed microorganisms are cultivated in fermenters to produce proteins from plant-based raw-materials. Since the protein produced are have identical amino acid sequences and structure as proteins that would be derived from animals, they provide the desired texture and sensory characteristics currently missing in plant-based formulations. For instance, our animal-free gelatin provides the functionality of thermally reversible gel. As our protein ingredients provides functionality and nutrition value of animal proteins, these ingredients could complement plant-based protein ingredients to deliver alt-protein food formulations more accurately emulate animal products, expand the market acceptance of alt-protein foods to mass consumers.
6
Corredig, Milena. "Processing plant proteins colloidal structures." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/cyqr3105.
Full textAbstract:
Food systems need to be designed to better fit within planetary boundaries. It is not only important to find more sustainable protein sources, but also to create fully circular, robust supply chains. But this is only the beginning: new formulations will need to fit common dietary expectations. The utilization of plant-based protein ingredients present significant challenges in relation to their nutritional and technological functionalities. Today these proteins do not measure up when used as ingredients in conventional processes. Plant protein streams contain polydisperse colloids, and detailed studies of their behaviour during processing is only at their infancy. To predict their structure-function, their physical and chemical changes need to be followed at various length scales. Furthermore, for each food matrix, depending on the final product needs, it will be required to find the appropriate level of refinement and processing history, to reach the right balance between sustainability and processing/nutritional functionality. This is currently a significant knowledge gap. This talk will outline how processing dynamics at the molecular and supramolecular level, affect the interactions occurring with the various components in mixed matrices, and will aim to inspire researchers to find new processing and formulation approaches that will better fit plant-based ingredients utilization, and with this accelerate progress towards a shift to more sustainable diets.
7
Chen, Lingyun. "Structural design of plant protein gel networks for food applications." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/wnsz2802.
Full textAbstract:
Gelation is one of the most important functional properties of proteins as it provides texture and structure in foods. Gelatin, egg white and whey proteins are widely used as gelling agents in the food industry. Plant proteins are considered inferior to animal proteins in gelling properties. With the recent surge in demand led by sustainability and health considerations, plant-based food products have taken a center stage in food product innovation. This trend has spurred academic and industrial interest to explore the opportunity of developing gelling ingredients from diversified plant protein sources, replacing animal protein based gels. This presentation will introduce the recent research efforts in our group to develop gelling properties from emerging sources of plant proteins (e.g. pea, lentil and oat). The structural design approaches (e.g. pH-shifting, protein aggregates to build gel network) and novel technologies (e.g. cold plasma, high pressure) that have potential to increase gel performances from plant proteins will be highlighted. The gel rheological properties and mechanical strength as impacted by the protein composition, conformation and aggregation will be discussed. The food application of plant protein based gels will be illustrated.
8
Kew, Ben, Anwesha Sarkar, Evan Liamas, and Jatin Sharma. "Modifying plant proteins as microgels for fat replacement applications." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/vqyk1732.
Full textAbstract:
With obesity being an increasing health concern, replacements of calorie-dense fat in diet is a necessity. Proteinaceous microgels have recently been found to have ultra-lubricating properties and are hypothesised to act as excellent fat replacers. However, such microgels have not been applied to more sustainable plant protein which is often associated with generating high friction in between oral contact surfaces and consequently generate astringency issues. The aim of this study was to design novel ultra-lubricating microgels using plant proteins and compare lubrication performance of various volume fractions (10-70 vol%) to that of a fat emulsion. An array of characterisation techniques combining oral tribology using 3D biomimetic tongue surface , rheology, dynamic light scattering (DLS), atomic force microscopy (AFM) and quartz crystal microbalance with dissipation (QCM-D) were used to characterise these newly designed microgels and their surface properties. Potato protein microgels at 5 and 10 wt% protein (PoPM5, PoPM10), pea protein microgel at 15 wt% protein (PePM15) and combined alternative protein microgel at 12.5 wt% (Po5:Pe7.5) were prepared at pH 7.0 by thermally crosslinking the proteins at 80°C for 30 minutes to form gels, followed by shearing. AFM and DLS revealed that microgels were sub-micron sized ranging in diameter from 85 to 232 nm with low polydispersity (‰¤ 0.25) . The microgels were relatively soft with storage modulus varying from 0.35 to 6.5 kPa. Irrespective of the type of proteins used, the microgel dispersions presented excellent lubrication performance especially owing to their adsorption properties as well as high effective viscosities. Strikingly, PePM15 microgels had similar friction coefficient values to that of the 20 wt% oil-in-water emulsion when introduced between 3D biomimetic tongue-like surface. Thus, we demonstrate for the first time that these sustainable protein microgels allow better incorporation of alternative protein in low calorie food without any negative mouthfeel consequences.
9
Zhou, Hualu, Giang Vu, and David J. McClements. "Rubisco Proteins as Plant-based Alternatives to Egg White Proteins: Characterization of Thermal Gelation Properties." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/vamx3998.
Full textAbstract:
RuBisCO proteins can be isolated from abundant and sustainable plant sources, such as duckweed (e.g., Lemnoideae). These plant-based globular proteins are capable of irreversibly unfolding and forming gels when heated, which means they may be able to mimic some of the functional attributes exhibited by animal globular proteins. In this study, we examined the ability of RuBisCo proteins to mimic the initial rheology and thermal gelation properties of egg white, which the aim of developing plant-based egg analogs. The impact of protein concentration (10-15% w/w), pH (7 to 9), and calcium concentration (0 to 50 mM CaCl2) on the properties of the egg white analogs was examined. The appearance (colorimetry), thermal denaturation (differential scanning calorimetry), thermal gelation (dynamic shear rheology), and texture profiles (compression testing) were measured. RuBisCO-based egg white analogs could be successfully produced at 10% protein content and pH 8 in the absence of salt. These RuBisCO protein solutions had similar apparent viscosity-shear rate profiles, shear modulus-temperature profiles, gelling temperatures, and final gel strengths as egg white. However, there were some differences. RuBisCO protein gels were slightly darker than egg white, which was attributed to the presence of some phenolic impurities. RuBisCo protein exhibited a single thermal transition temperature (~ 66 ℃) whereas egg white exhibited two (~66 and ~81 ℃). RuBisCo protein gels were more brittle but less chewy and resilient than egg white gels. This study provides valuable insights into the potential of RuBisCo protein for formulating plant-based egg white analogs, which may help improve the sustainability of the modern food supply.
10
Henning, Kellen. "Using the BioID Approach to Identify Proteins Interacting with the P0 Protein from Turnip Yellows Virus." In ASPB PLANT BIOLOGY 2020. USA: ASPB, 2020. http://dx.doi.org/10.46678/pb.20.1053038.
Full textReports on the topic "Plant proteins"
1
Galili, Gad, and Alan Bennett. Role of Molecular Chaperone in Wheat Storage Protein Assembly. United States Department of Agriculture, April 1995. http://dx.doi.org/10.32747/1995.7604926.bard.
Full textAbstract:
Following sequestration into the ER, wheat gliadins assemble into complexes that initiate the formation of protein bodies. In the present work we have characterized the DNA sequence and regulation of expression of a plant BiP and also studied its interaction with wheat storage proteins as well as its role in the maturation of these storage proteins. In the Israeli lab, immunoprecipitation studies were made using anti BiP and anti storage proteins sera, both in wheat and in transgenic tobacco plants expressing a wheat gliadin storage proteins. In both cases, we could show that BiP interacts with the gliadin storage proteins. In addition, we could show that BiP also played an important role in the initial assembly of the gliadins. In the American lab, the complexity, structure and properties of tomato BiP was characterized at the molecular and biochemical levels. In addition, tomato BiP was also overexpressed in bacteria and the overexpressed protein was found to be active. The cooperative findings of the Israeli and American labs clearly improves our understanding of the structure and expression of a plant BiP as well as its role in the maturation of storage proteins in plants seeds. In addition, it will serve as a foundation for future studies of the mechanisms of BiP function in in vitro studies using purified storage proteins and purified recombinant active BiP.
2
Christopher, David A., and Avihai Danon. Plant Adaptation to Light Stress: Genetic Regulatory Mechanisms. United States Department of Agriculture, May 2004. http://dx.doi.org/10.32747/2004.7586534.bard.
Full textAbstract:
Original Objectives: 1. Purify and biochemically characterize RB60 orthologs in higher plant chloroplasts; 2. Clone the gene(s) encoding plant RB60 orthologs and determine their structure and expression; 3. Manipulate the expression of RB60; 4. Assay the effects of altered RB60 expression on thylakoid biogenesis and photosynthetic function in plants exposed to different light conditions. In addition, we also examined the gene structure and expression of RB60 orthologs in the non-vascular plant, Physcomitrella patens and cloned the poly(A)-binding protein orthologue (43 kDa RB47-like protein). This protein is believed to a partner that interacts with RB60 to bind to the psbA5' UTR. Thus, to obtain a comprehensive view of RB60 function requires analysis of its biochemical partners such as RB43. Background & Achievements: High levels of sunlight reduce photosynthesis in plants by damaging the photo system II reaction center (PSII) subunits, such as D1 (encoded by the chloroplast tpsbAgene). When the rate of D1 synthesis is less than the rate of photo damage, photo inhibition occurs and plant growth is decreased. Plants use light-activated translation and enhanced psbAmRNA stability to maintain D1 synthesis and replace the photo damaged 01. Despite the importance to photosynthetic capacity, these mechanisms are poorly understood in plants. One intriguing model derived from the algal chloroplast system, Chlamydomonas, implicates the role of three proteins (RB60, RB47, RB38) that bind to the psbAmRNA 5' untranslated leader (5' UTR) in the light to activate translation or enhance mRNA stability. RB60 is the key enzyme, protein D1sulfide isomerase (Pill), that regulates the psbA-RN :Binding proteins (RB's) by way of light-mediated redox potentials generated by the photosystems. However, proteins with these functions have not been described from higher plants. We provided compelling evidence for the existence of RB60, RB47 and RB38 orthologs in the vascular plant, Arabidopsis. Using gel mobility shift, Rnase protection and UV-crosslinking assays, we have shown that a dithiol redox mechanism which resembles a Pill (RB60) activity regulates the interaction of 43- and 30-kDa proteins with a thermolabile stem-loop in the 5' UTR of the psbAmRNA from Arabidopsis. We discovered, in Arabidopsis, the PD1 gene family consists of II members that differ in polypeptide length from 361 to 566 amino acids, presence of signal peptides, KDEL motifs, and the number and positions of thioredoxin domains. PD1's catalyze the reversible formation an disomerization of disulfide bonds necessary for the proper folding, assembly, activity, and secretion of numerous enzymes and structural proteins. PD1's have also evolved novel cellular redox functions, as single enzymes and as subunits of protein complexes in organelles. We provide evidence that at least one Pill is localized to the chloroplast. We have used PDI-specific polyclonal and monoclonal antisera to characterize the PD1 (55 kDa) in the chloroplast that is unevenly distributed between the stroma and pellet (containing membranes, DNA, polysomes, starch), being three-fold more abundant in the pellet phase. PD1-55 levels increase with light intensity and it assembles into a high molecular weight complex of ~230 kDa as determined on native blue gels. In vitro translation of all 11 different Pill's followed by microsomal membrane processing reactions were used to differentiate among PD1's localized in the endoplasmic reticulum or other organelles. These results will provide.1e insights into redox regulatory mechanisms involved in adaptation of the photosynthetic apparatus to light stress. Elucidating the genetic mechanisms and factors regulating chloroplast photosynthetic genes is important for developing strategies to improve photosynthetic efficiency, crop productivity and adaptation to high light environments.
3
Ohad, Nir, and Robert Fischer. Regulation of plant development by polycomb group proteins. United States Department of Agriculture, January 2008. http://dx.doi.org/10.32747/2008.7695858.bard.
Full textAbstract:
Our genetic and molecular studies have indicated that FIE a WD-repeat Polycomb group (PcG) protein takes part in multi-component protein complexes. We have shown that FIE PcG protein represses inappropriate programs of development during the reproductive and vegetative phases of the Arabidopsis life cycle. Moreover, we have shown that FIE represses the expression of key regulatory genes that promote flowering (AG and LFY), embryogenesis (LEC1), and shoot formation (KNAT1). These results suggest that the FIE PcG protein participates in the formation of distinct PcG complexes that repress inappropriate gene expression at different stages of plant development. PcG complexes modulate chromatin compactness by modifying histones and thereby regulate gene expression and imprinting. The main goals of our original project were to elucidate the biological functions of PcG proteins, and to understand the molecular mechanisms used by FIE PcG complexes to repress the expression of its gene targets. Our results show that the PcG complex acts within the central cell of the female gametophyte to maintain silencing of MEA paternal allele. Further more we uncovered a novel example of self-imprinting mechanism by the PgG complex. Based on results obtained in the cures of our research program we extended our proposed goals and elucidated the role of DME in regulating plant gene imprinting. We discovered that in addition to MEA,DME also imprints two other genes, FWA and FIS2. Activation of FWA and FIS2 coincides with a reduction in 5-methylcytosine in their respective promoters. Since endosperm is a terminally differentiated tissue, the methylation status in the FWA and FIS2 promoters does not need to be reestablished in the following generation. We proposed a “One-Way Control” model to highlight differences between plant and animal genomic imprinting. Thus we conclude that DEMETER is a master regulator of plant gene imprinting. Future studies of DME function will elucidate its role in processes and disease where DNA methylation has a key regulatory role both in plants and animals. Such information will provide valuable insight into developing novel strategies to control and improve agricultural traits and overcome particular human diseases.
4
Chamovitz, Daniel A., and Zhenbiao Yang. Chemical Genetics of the COP9 Signalosome: Identification of Novel Regulators of Plant Development. United States Department of Agriculture, January 2011. http://dx.doi.org/10.32747/2011.7699844.bard.
Full textAbstract:
This was an exploratory one-year study to identify chemical regulators of the COP9 signalosome. Chemical Genetics uses small molecules to modify or disrupt the function of specific genes/proteins. This is in contrast to classical genetics, in which mutations disrupt the function of genes. The underlying concept is that the functions of most proteins can be altered by the binding of a chemical, which can be found by screening large libraries for compounds that specifically affect a biological, molecular or biochemical process. In addition to screens for chemicals which inhibit specific biological processes, chemical genetics can also be employed to find inhibitors of specific protein-protein interactions. Small molecules altering protein-protein interactions are valuable tools in probing protein-protein interactions. In this project, we aimed to identify chemicals that disrupt the COP9 signalosome. The CSN is an evolutionarily conserved eight-subunit protein complex whose most studied role is regulation of E3 ubiquitinligase activity. Mutants in subunits of the CSN undergo photomorphogenesis in darkness and accumulate high levels of pigments in both dark- and light-grown seedlings, and are defective in a wide range of important developmental and environmental-response pathways. Our working hypothesis was that specific molecules will interact with the CSN7 protein such that binding to its various interacting proteins will be inhibited. Such a molecule would inhibit either CSN assembly, or binding of CSN-interacting proteins, and thus specifically inhibit CSN function. We used an advanced chemical genetic screen for small-molecule-inhibitors of CSN7 protein-protein interactions. In our pilot study, following the screening of ~1200 unique compounds, we isolated four chemicals which reproducibly interfere with CSN7 binding to either CSN8 or CSN6.
5
Barakat, Dr Shima, Dr Samuel Short, Dr Bernhard Strauss, and Dr Pantea Lotfian. https://www.food.gov.uk/research/research-projects/alternative-proteins-for-human-consumption. Food Standards Agency, June 2022. http://dx.doi.org/10.46756/sci.fsa.wdu243.
Full textAbstract:
The UK is seeing growing interest in alternative protein sources to traditional animal-based proteins such as beef, lamb, pork, poultry, fish, eggs, and dairy. There is already an extensive market in alternative protein materials, however, technological advances combined with the pressure for more sustainable sources of protein has led to an acceleration of innovation and product development and the introduction of a large amount of new alternative protein ingredients and products to the market. These have the potential to dramatically impact on the UK food system. This report is a combination of desk research, based on thorough review of the academic and non-academic literature and of the alternative proteins start-up scene, and presents an analysis of the emerging market for alternative proteins, the potential implications and the potential policy responses that the FSA might need to consider. Four main categories of alternative proteins are presented and reviewed in this report: Plant-based meat substitutes Novel protein sources Proteins and biomass biosynthesised by microorganisms Cultured meat
6
Ohad, Nir, and Robert Fischer. Regulation of Fertilization-Independent Endosperm Development by Polycomb Proteins. United States Department of Agriculture, January 2004. http://dx.doi.org/10.32747/2004.7695869.bard.
Full textAbstract:
Arabidopsis mutants that we have isolated, encode for fertilization-independent endosperm (fie), fertilization-independent seed2 (fis2) and medea (mea) genes, act in the female gametophyte and allow endosperm to develop without fertilization when mutated. We cloned the FIE and MEA genes and showed that they encode WD and SET domain polycomb (Pc G) proteins, respectively. Homologous proteins of FIE and MEA in other organisms are known to regulate gene transcription by modulating chromatin structure. Based on our results, we proposed a model whereby both FIE and MEA interact to suppress transcription of regulatory genes. These genes are transcribed only at proper developmental stages, as in the central cell of the female gametophyte after fertilization, thus activating endosperm development. To test our model, the following questions were addressed: What is the Composition and Function of the Polycomb Complex? Molecular, biochemical, genetic and genomic approaches were offered to identify members of the complex, analyze their interactions, and understand their function. What is the Temporal and Spatial Pattern of Polycomb Proteins Accumulation? The use of transgenic plants expressing tagged FIE and MEA polypeptides as well as specific antibodies were proposed to localize the endogenous polycomb complex. How is Polycomb Protein Activity Controlled? To understand the molecular mechanism controlling the accumulation of FIE protein, transgenic plants as well as molecular approaches were proposed to determine whether FIE is regulated at the translational or posttranslational levels. The objectives of our research program have been accomplished and the results obtained exceeded our expectation. Our results reveal that fie and mea mutations cause parent-of-origin effects on seed development by distinct mechanisms (Publication 1). Moreover our data show that FIE has additional functions besides controlling the development of the female gametophyte. Using transgenic lines in which FIE was not expressed or the protein level was reduced during different developmental stages enabled us for the first time to explore FIE function during sporophyte development (Publication 2 and 3). Our results are consistent with the hypothesis that FIE, a single copy gene in the Arabidopsis genome, represses multiple developmental pathways (i.e., endosperm, embryogenesis, shot formation and flowering). Furthermore, we identified FIE target genes, including key transcription factors known to promote flowering (AG and LFY) as well as shoot and leaf formation (KNAT1) (Publication 2 and 3), thus demonstrating that in plants, as in mammals and insects, PcG proteins control expression of homeobox genes. Using the Yeast two hybrid system and pull-down assays we demonstrated that FIE protein interact with MEA via the N-terminal region (Publication 1). Moreover, CURLY LEAF protein, an additional member of the SET domain family interacts with FIE as well. The overlapping expression patterns of FIE, with ether MEA or CLF and their common mutant phenotypes, demonstrate the versatility of FIE function. FIE association with different SET domain polycomb proteins, results in differential regulation of gene expression throughout the plant life cycle (Publication 3). In vitro interaction assays we have recently performed demonstrated that FIE interacts with the cell cycle regulatory component Retinobalsoma protein (pRb) (Publication 4). These results illuminate the potential mechanism by which FIE may restrain embryo sac central cell division, at least partly, through interaction with, and suppression of pRb-regulated genes. The results of this program generated new information about the initiation of reproductive development and expanded our understanding of how PcG proteins regulate developmental programs along the plant life cycle. The tools and information obtained in this program will lead to novel strategies which will allow to mange crop plants and to increase crop production.
7
Ostersetzer-Biran, Oren, and Alice Barkan. Nuclear Encoded RNA Splicing Factors in Plant Mitochondria. United States Department of Agriculture, February 2009. http://dx.doi.org/10.32747/2009.7592111.bard.
Full textAbstract:
Mitochondria are the site of respiration and numerous other metabolic processes required for plant growth and development. Increased demands for metabolic energy are observed during different stages in the plants life cycle, but are particularly ample during germination and reproductive organ development. These activities are dependent upon the tight regulation of the expression and accumulation of various organellar proteins. Plant mitochondria contain their own genomes (mtDNA), which encode for a small number of genes required in organellar genome expression and respiration. Yet, the vast majority of the organellar proteins are encoded by nuclear genes, thus necessitating complex mechanisms to coordinate the expression and accumulation of proteins encoded by the two remote genomes. Many organellar genes are interrupted by intervening sequences (introns), which are removed from the primary presequences via splicing. According to conserved features of their sequences these introns are all classified as “group-II”. Their splicing is necessary for organellar activity and is dependent upon nuclear-encoded RNA-binding cofactors. However, to-date, only a tiny fraction of the proteins expected to be involved in these activities have been identified. Accordingly, this project aimed to identify nuclear-encoded proteins required for mitochondrial RNA splicing in plants, and to analyze their specific roles in the splicing of group-II intron RNAs. In non-plant systems, group-II intron splicing is mediated by proteins encoded within the introns themselves, known as maturases, which act specifically in the splicing of the introns in which they are encoded. Only one mitochondrial intron in plants has retained its maturaseORF (matR), but its roles in organellar intron splicing are unknown. Clues to other proteins required for organellar intron splicing are scarce, but these are likely encoded in the nucleus as there are no other obvious candidates among the remaining ORFs within the mtDNA. Through genetic screens in maize, the Barkan lab identified numerous nuclear genes that are required for the splicing of many of the introns within the plastid genome. Several of these genes are related to one another (i.e. crs1, caf1, caf2, and cfm2) in that they share a previously uncharacterized domain of archaeal origin, the CRM domain. The Arabidopsis genome contains 16 CRM-related genes, which contain between one and four repeats of the domain. Several of these are predicted to the mitochondria and are thus postulated to act in the splicing of group-II introns in the organelle(s) to which they are localized. In addition, plant genomes also harbor several genes that are closely related to group-II intron-encoded maturases (nMats), which exist in the nucleus as 'self-standing' ORFs, out of the context of their cognate "host" group-II introns and are predicted to reside within the mitochondria. The similarity with known group-II intron splicing factors identified in other systems and their predicted localization to mitochondria in plants suggest that nuclear-encoded CRM and nMat related proteins may function in the splicing of mitochondrial-encoded introns. In this proposal we proposed to (i) establish the intracellular locations of several CRM and nMat proteins; (ii) to test whether mutations in their genes impairs the splicing of mitochondrial introns; and to (iii) determine whether these proteins are bound to the mitochondrial introns in vivo.
8
Avni, Adi, and Gitta L. Coaker. Proteomic investigation of a tomato receptor like protein recognizing fungal pathogens. United States Department of Agriculture, January 2015. http://dx.doi.org/10.32747/2015.7600030.bard.
Full textAbstract:
Maximizing food production with minimal negative effects on the environment remains a long-term challenge for sustainable food production. Microbial pathogens cause devastating diseases, minimizing crop losses by controlling plant diseases can contribute significantly to this goal. All plants possess an innate immune system that is activated after recognition of microbial-derived molecules. The fungal protein Eix induces defense responses in tomato and tobacco. Plants recognize Eix through a leucine-rich-repeat receptor- like-protein (LRR-RLP) termed LeEix. Despite the knowledge obtained from studies on tomato, relatively little is known about signaling initiated by RLP-type immune receptors. The focus of this grant proposal is to generate a foundational understanding of how the tomato xylanase receptor LeEix2 signals to confer defense responses. LeEix2 recognition results in pattern triggered immunity (PTI). The grant has two main aims: (1) Isolate the LeEix2 protein complex in an active and resting state; (2) Examine the biological function of the identified proteins in relation to LeEix2 signaling upon perception of the xylanase elicitor Eix. We used two separate approaches to isolate receptor interacting proteins. Transgenic tomato plants expressing LeEix2 fused to the GFP tag were used to identify complex components at a resting and activated state. LeEix2 complexes were purified by mass spectrometry and associated proteins identified by mass spectrometry. We identified novel proteins that interact with LeEix receptor by proteomics analysis. We identified two dynamin related proteins (DRPs), a coiled coil – nucleotide binding site leucine rich repeat (SlNRC4a) protein. In the second approach we used the split ubiquitin yeast two hybrid (Y2H) screen system to identified receptor-like protein kinase At5g24010-like (SlRLK-like) (Solyc01g094920.2.1) as an interactor of LeEIX2. We examined the role of SlNRC4a in plant immunity. Co-immunoprecipitation demonstrates that SlNRC4a is able to associate with different PRRs. Physiological assays with specific elicitors revealed that SlNRC4a generally alters PRR-mediated responses. SlNRC4a overexpression enhances defense responses while silencing SlNRC4 reduces plant immunity. We propose that SlNRC4a acts as a non-canonical positive regulator of immunity mediated by diverse PRRs. Thus, SlNRC4a could link both intracellular and extracellular immune perception. SlDRP2A localizes at the plasma membrane. Overexpression of SlDRP2A increases the sub-population of LeEIX2 inVHAa1 endosomes, and enhances LeEIX2- and FLS2-mediated defense. The effect of SlDRP2A on induction of plant immunity highlights the importance of endomembrane components and endocytosis in signal propagation during plant immune . The interaction of LeEIX2 with SlRLK-like was verified using co- immunoprecipitation and a bimolecular fluorescence complementation assay. The defence responses induced by EIX were markedly reduced when SlRLK-like was over-expressed, and mutation of slrlk-likeusing CRISPR/Cas9 increased EIX- induced ethylene production and SlACSgene expression in tomato. Co-expression of SlRLK-like with different RLPs and RLKs led to their degradation, apparently through an endoplasmic reticulum-associated degradation process. We provided new knowledge and expertise relevant to expression of specific be exploited to enhance immunity in crops enabling the development of novel environmentally friendly disease control strategies.
9
Coplin, David, Isaac Barash, and Shulamit Manulis. Role of Proteins Secreted by the Hrp-Pathways of Erwinia stewartii and E. herbicola pv. gypsophilae in Eliciting Water-Soaking Symptoms and Initiating Galls. United States Department of Agriculture, June 2001. http://dx.doi.org/10.32747/2001.7580675.bard.
Full textAbstract:
Many bacterial pathogens of plants can inject pathogenicity proteins into host cells using a specialized type III secretion system encoded by hrpgenes. This system deliver effector proteins, into plant cells that function in both susceptible and resistant interactions. We have found that the virulence of Erwinia stewartii(Es; syn. Pantoea stewartii) and Erwinia herbicola pv. gypsophilae (Ehg, syn. Pantoea agglomerans), which cause Stewart's wilt of corn and galls on Gypsophila, respectively, depends on hrpgenes. The major objectives of this project were: To increase expression of hrpgenes in order to identify secreted proteins; to identify genes for proteins secreted by the type-III systems and determine if they are required for pathogenicity; and to determine if the secreted proteins can function within eukaryotic cells. We found that transcription of the hrp and effector genes in Es and Ehg is controlled by at least four genes that constitute a regulatory cascade. Environmental and/or physiological signaling appears to be mediated by the HrpX/HrpY two component system, with HrpX functioning as a sensor-kinase and HrpY as a response regulator. HrpYupregulateshrpS, which encodes a transcriptional enhancer. HrpS then activates hrpL, which encodes an alternate sigma factor that recognizes "hrp boxes". All of the regulatory genes are essential for pathogenicity, except HrpX, which appears only to be required for induction of the HR in tobacco by Es. In elucidating this regulatory pathway in both species, we made a number of significant new discoveries. HrpX is unusual for a sensor-kinase because it is cytoplasmic and contains PAS domains, which may sense the redox state of the bacterium. In Es, a novel methyl-accepting protein may function upstream of hrpY and repress hrp gene expression in planta. The esaIR quorum sensing system in Es represses hrp gene expression in Es in response to cell-density. We have discovered six new type III effector proteins in these species, one of which (DspE in Ehg and WtsE in Es) is common to both pathogens. In addition, Es wtsG, which is a homolog of an avrPpiB from P. syringae pv. pisi, and an Ehg ORF, which is a homolog of P. syringae pv. phaseolicola AvrPphD, were both demonstrated to encode virulence proteins. Two plasmidborne, Ehg Hop proteins, HsvG and PthG, are required for infection of gypsophilia, but interestingly, PthG also acts as an Avr elicitor in beets. Using a calmodulin-dependent adenylate cyclase (cyaA) reporter gene, we were successful in demonstrating that an HsvG-CyaA fusion protein can be transferred into human HeLa cells by the type-III system of enteropathogenic E. coli. This is a highly significant accomplishment because it is the first direct demonstration that an effector protein from a plant pathogenic bacterium is capable of being translocated into a eukaryotic cell by a type-III secretion system. Ehg is considered a limiting factor in Gypsophila production in Israel and Stewart’s Wilt is a serious disease in the Eastern and North Central USA, especially on sweet corn in epidemic years. We believe that our basic research on the characterization of type III virulence effectors should enable future identification of their receptors in plant cells. This may lead to novel approaches for genetically engineering resistant plants by modifying their receptors or inactivating effectors and thus blocking the induction of the susceptible response. Alternatively, hrp gene regulation might also provide a target for plant produced compounds that interfere with recognition of the host by the pathogen. Such strategies would be broadly applicable to a wide range of serious bacterial diseases on many crops throughout the USA and Israel.
10
Coplin, David L., Shulamit Manulis, and Isaac Barash. roles Hrp-dependent effector proteins and hrp gene regulation as determinants of virulence and host-specificity in Erwinia stewartii and E. herbicola pvs. gypsophilae and betae. United States Department of Agriculture, June 2005. http://dx.doi.org/10.32747/2005.7587216.bard.
Full textAbstract:
Gram-negative plant pathogenic bacteria employ specialized type-III secretion systems (TTSS) to deliver an arsenal of pathogenicity proteins directly into host cells. These secretion systems are encoded by hrp genes (for hypersensitive response and pathogenicity) and the effector proteins by so-called dsp or avr genes. The functions of effectors are to enable bacterial multiplication by damaging host cells and/or by blocking host defenses. We characterized essential hrp gene clusters in the Stewart's Wilt of maize pathogen, Pantoea stewartii subsp. stewartii (Pnss; formerly Erwinia stewartii) and the gall-forming bacterium, Pantoea agglomerans (formerly Erwinia herbicola) pvs. gypsophilae (Pag) and betae (Pab). We proposed that the virulence and host specificity of these pathogens is a function of a) the perception of specific host signals resulting in bacterial hrp gene expression and b) the action of specialized signal proteins (i.e. Hrp effectors) delivered into the plant cell. The specific objectives of the proposal were: 1) How is the expression of the hrp and effector genes regulated in response to host cell contact and the apoplastic environment? 2) What additional effector proteins are involved in pathogenicity? 3) Do the presently known Pantoea effector proteins enter host cells? 4) What host proteins interact with these effectors? We characterized the components of the hrp regulatory cascade (HrpXY ->7 HrpS ->7 HrpL ->7 hrp promoters), showed that they are conserved in both Pnss and Fag, and discovered that the regulation of the hrpS promoter (hrpSp) may be a key point in integrating apoplastic signals. We also analyzed the promoters recognized by HrpL and demonstrated the relationship between their composition and efficiency. Moreover, we showed that promoter strength can influence disease expression. In Pnss, we found that the HrpXY two-component signal system may sense the metabolic status of the bacterium and is required for full hrp gene expression in planta. In both species, acyl-homoserine lactone-mediated quorum sensing may also regulate epiphytic fitness and/or pathogenicity. A common Hrp effector protein, DspE/WtsE, is conserved and required for virulence of both species. When introduced into corn cells, Pnss WtsE protein caused water-soaked lesions. In other plants, it either caused cell death or acted as an Avr determinant. Using a yeast- two-hybrid system, WtsE was shown to interact with a number of maize signal transduction proteins that are likely to have roles in either programmed cell death or disease resistance. In Pag and Pab, we have characterized the effector proteins HsvG, HsvB and PthG. HsvG and HsvB are homologous proteins that determine host specificity of Pag and Pab on gypsophila and beet, respectively. Both possess a transcriptional activation domain that functions in yeast. PthG was found to act as an Avr determinant on multiple beet species, but was required for virulence on gypsophila. In addition, we demonstrated that PthG acts within the host cell. Additional effector genes have been characterized on the pathogenicity plasmid, pPATHₚₐg, in Pag. A screen for HrpL- regulated genes in Pnsspointed up 18 candidate effector proteins and four of these were required for full virulence. It is now well established that the virulence of Gram-negative plant pathogenic bacteria is governed by Hrp-dependent effector proteins. However; the mode of action of many effectors is still unresolved. This BARD supported research will significantly contribute to the understanding of how Hrp effectors operate in Pantoea spp. and how they control host specificity and affect symptom production. This may lead to novel approaches for genetically engineering plants resistant to a wide range of bacterial pathogens by inactivating the Hrp effectors with "plantabodies" or modifying their receptors, thereby blocking the induction of the susceptible response. Alternatively, innovative technologies could be used to interfere with the Hrp regulatory cascade by blocking a critical step or mimicking plant or quorum sensing signals.