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Slazak, Blazej
Publications (3 of 3) Show all publications
Slazak, B., Kapusta, M., Strömstedt, A. A., Slomka, A., Krychowiak, M., Shariatgorji, M., . . . Göransson, U. (2018). How Does the Sweet Violet (Viola odorata L.) Fight Pathogens and Pests - Cyclotides as a Comprehensive Plant Host Defense System. Frontiers in Plant Science, 9, Article ID 1296.
Open this publication in new window or tab >>How Does the Sweet Violet (Viola odorata L.) Fight Pathogens and Pests - Cyclotides as a Comprehensive Plant Host Defense System
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2018 (English)In: Frontiers in Plant Science, ISSN 1664-462X, E-ISSN 1664-462X, Vol. 9, article id 1296Article in journal (Refereed) Published
Abstract [en]

Cyclotides are cyclic plant polypeptides of 27-37 amino acid residues. They have been extensively studied in bioengineering and drug development contexts. However, less is known about the relevance of cyclotides for the plants producing them. The anti-insect larvae effects of kB1 and antibacterial activity of cyO2 suggest that cyclotides are a part of plant host defense. The sweet violet (Viola odorata L.) produces a wide array of cyclotides, including kB1 (kalata B1) and cyO2 (cycloviolacin O2), with distinct presumed biological roles. Here, we evaluate V. odorata cyclotides' potency against plant pathogens and their mode of action using bioassays, liposome experiments and immunogold labeling for transmission electron microscopy (TEM). We explore the link between the biological activity and distribution in plant generative, vegetative tissues and seeds, depicted by immunohistochemistry and matrix assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI). Cyclotides cyO2, cyO3, cyO13, and cyO19 are shown to have potent activity against model fungal plant pathogens (Fusarium oxysporum, F. graminearum, F. culmorum, Mycosphaerella fragariae, Botrytis cinerea) and fungi isolated from violets (Colletotrichum utrechtense and Alternaria alternata), with minimal inhibitory concentrations (MICs) ranging from 0.8 to 25 mu M. Inhibition of phytopathogenic bacteria - Pseudomonas syringae pv. syringae, Dickeya dadantii and Pectobacterium atrosepticum - is also observed with MIC = 25-100 mu M. A membrane-disrupting antifungal mode of action is shown. Finding cyO2 inside the fungal spore cells in TEM images may indicate that other, intracellular targets may be involved in the mechanism of toxicity. Fungi can not break down cyclotides in the course of days. varv A (kalata S) and kB1 show little potency against pathogenic fungi when compared with the tested cycloviolacins. cyO2, cyO3, cyO19 and kB1 are differentially distributed and found in tissues vulnerable to pathogen (epidermis, rizodermis, vascular bundles, protodermis, procambium, ovary walls, outer integuments) and pest ( ground tissues of leaf and petiole) attacks, respectively, indicating a link between the cyclotides' sites of accumulation and biological role. Cyclotides emerge as a comprehensive defense system in V. odorata, in which different types of peptides have specific targets that determine their distribution in plant tissues.

Place, publisher, year, edition, pages
cyclotides, plant host defense, Violaceae, antimicrobial peptide, antifungal defense, MALDI-MSI, immunohistochemistry
National Category
urn:nbn:se:uu:diva-365299 (URN)10.3389/fpls.2018.01296 (DOI)000444243600001 ()30254654 (PubMedID)
Swedish Research Council, 621-2007-5167Swedish Research Council, 621-2014-6215Swedish Foundation for Strategic Research , RIF14-0078Science for Life Laboratory - a national resource center for high-throughput molecular bioscience
Available from: 2018-11-13 Created: 2018-11-13 Last updated: 2018-11-13Bibliographically approved
Göransson, U., Gunasekera, S., Malik, S., Park, S., Slazak, B., Jacobsson, E., . . . Strömstedt, A. A. (2016). Peptide biodiscovery from plants and animals: structure to function. Paper presented at 9th Joint Meeting of AFERP, ASP, GA, JSP, PSE and SIF, JUL 24-27, 2016, Copenhagen, DENMARK. Planta Medica, 82
Open this publication in new window or tab >>Peptide biodiscovery from plants and animals: structure to function
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2016 (English)In: Planta Medica, ISSN 0032-0943, E-ISSN 1439-0221, Vol. 82Article in journal, Meeting abstract (Other academic) Published
Peptide biodiscovery, cyclotides, sponge peptides, cacti
National Category
Basic Medicine
urn:nbn:se:uu:diva-346852 (URN)10.1055/s-0036-1596156 (DOI)000411789300953 ()
9th Joint Meeting of AFERP, ASP, GA, JSP, PSE and SIF, JUL 24-27, 2016, Copenhagen, DENMARK
Available from: 2018-03-27 Created: 2018-03-27 Last updated: 2018-03-27Bibliographically approved
Göransson, U., Malik, S. & Slazak, B. (2015). Cyclotides in the Violaceae. In: Craik, David J. (Ed.), Plant Cyclotides: (pp. 15-49). Academic Press, 76
Open this publication in new window or tab >>Cyclotides in the Violaceae
2015 (English)In: Plant Cyclotides / [ed] Craik, David J., Academic Press , 2015, Vol. 76, p. 15-49Chapter in book (Other academic)
Abstract [en]

Abstract It has been 20 years since the cyclic cystine-knotted compounds, called cyclotides, tied our knot with the violets. This chapter, above all, is a lucid summary of the twists, turns, knots, and rings in the relationship that followed. The chapter begins by giving an account of how a little known scientific article facilitated the discovery of cyclotides in Violaceae, how it captured our imagination, and how it was realized that the discovery of a series of cyclotides was within a touching distance. The processes of extraction, isolation, and characterization as well as chemical synthesis of cyclotides used in our laboratory have been described, and in doing so, the solvents, materials, conditions, instrumentation, and techniques involved have been pointed out. An introduction to Violaceae and a description of these plants in diverse cultural settings for various therapeutic purposes is provided. A section follows it on the discovery of cycloviolacin O2 from Viola odorata as a potent antimicrobial peptide, and how its interaction with bacteria in terms of mechanism of action and resistance development was investigated. It is followed by a reflection on how the recent innovations in biotechnology and bioinformatics have helped out along the way: the use of novel strategies for cyclization and the use of transcriptomics data in the discovery of new cyclotides. Finally, the question about biological role of cyclotides in Violaceae has been asked, and an attempt to answer this question has been presented.

Place, publisher, year, edition, pages
Academic Press, 2015
Advances in Botanical Research ; 76
Cyclotides, Discovery, Pharmacognosy, Traditional medicine, Violaceae
National Category
Research subject
urn:nbn:se:uu:diva-278985 (URN)10.1016/bs.abr.2015.09.001 (DOI)000376190900003 ()9780128007976 (ISBN)9780128000304 (ISBN)
Available from: 2016-02-27 Created: 2016-02-27 Last updated: 2018-06-04Bibliographically approved

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