Exogenous plant hormones and cyclotide expression in Viola uliginosa (Violaceae)

Ślązak, Błażej; Jacobsson, Erik; Kuta, Elżbieta; Göransson, Ulf

doi:10.1016/j.phytochem.2015.07.016

Cited by 32 publications

(57 citation statements)

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“…Cyclotides are synthesized and deposited in all parts of the plants producing them, but individual organs and tissues have their own distinct cyclotide distributions that differ in terms of quantity and diversity of sequences ( Trabi and Craik, 2004 ; Slazak et al, 2015 ). It is suggested that the cyclotide suites expressed in specific organs and tissues are shaped by the environment and the challenges it presents to the plant, such as pathogen or insect attacks ( Gilding et al, 2016 ; Slazak et al, 2016 ).…”

Section: Introductionmentioning

confidence: 99%

How Does the Sweet Violet (Viola odorata L.) Fight Pathogens and Pests – Cyclotides as a Comprehensive Plant Host Defense System

et al. 2018

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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 μM to 25 μM. Inhibition of phytopathogenic bacteria – Pseudomonas syringae pv. syringae, Dickeya dadantii and Pectobacterium atrosepticum – is also observed with MIC = 25–100 μM. 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.

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Section: Introductionmentioning

confidence: 99%

How Does the Sweet Violet (Viola odorata L.) Fight Pathogens and Pests – Cyclotides as a Comprehensive Plant Host Defense System

et al. 2018

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“…Notably there is often a certain level of mismatch observed between sequences obtained from transcriptome and proteome data . Firstly, putative mature cyclotide domains within nucleotide datasets are always assigned based on homology with already known sequences.…”

Section: Endless Peptides and Never‐ending Questionsmentioning

confidence: 99%

“…Importantly it has to be mentioned that the presence of peptides may differ within different samples of the same species. This can be due to tissue‐specific expression, seasonal changes in peptide expression or exposure to different environmental conditions that might affect expression patterns both at transcript and peptide levels . Hence samples used for combined proteome/nucleotide approaches should ideally originate from the same plant and the same tissue to reduce mismatching, although even this cannot rule out discrepancies between precursor and mature peptide sequences .…”

Section: Endless Peptides and Never‐ending Questionsmentioning

confidence: 99%

“…This can be due to tissue‐specific expression, seasonal changes in peptide expression or exposure to different environmental conditions that might affect expression patterns both at transcript and peptide levels . Hence samples used for combined proteome/nucleotide approaches should ideally originate from the same plant and the same tissue to reduce mismatching, although even this cannot rule out discrepancies between precursor and mature peptide sequences . Other possibilities that can cause a mismatch are sequencing or assembling errors for nucleotide derived data or the creation of peptide artefacts due to harsh experimental handling of samples.…”

Section: Endless Peptides and Never‐ending Questionsmentioning

confidence: 99%

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Unveiling the diversity of cyclotides by combining peptidome and transcriptome analysis

Koehbach

Clark

2016

Biopolymers

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Circular peptides have attracted much interest in recent drug development efforts, particularly due to their increased stability over linear counterparts. The family of plant cyclotides represents one of the largest classes of naturally-occurring backbone-cyclized peptides displaying exceptional sequence variability and plasticity around three knotted disulfide bonds. Accordingly, a multitude of pharmaceutically as well as agrochemically relevant bioactivities has been ascribed to them. Their abundance across various species within flowering plants is highlighted by estimated numbers of up to 150,000 different sequences present in single plant families and over 160 at the species level. However, this vast diversity impedes thorough sequence characterization by standard analytical methods using mass spectrometry and thus limits access to a wealth of potentially bioactive compounds that may represent novel lead molecules. Recently the ribosomal origin of cyclotides has been exploited as an alternative way to discover novel sequences. The analysis at nucleotide level allows not only the identification of peptides but also their parent precursor proteins. This combined approach opens access to the discovery of sequences that can provide novel structural templates for a variety of pharmaceutical as well as agrochemical applications. Here we review recent literature related to the discovery of cyclotides. Challenges and opportunities using classical mass spectrometry workflows and novel approaches such as in silico mining will be discussed. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 774-783, 2016.

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“…Although micropropagation via direct and indirect organogenesis was successful, 36-75% of regenerated plants (depending on experiment) were tetraploid, in spite of being derived from a diploid (2n = 20) tissue, due to somaclonal variation. Regenerated tetraploids producing a higher than diploids amount of cyclotides (plant defensive peptides) have rather pharmaceutical value and do not provide an appropriate material for introduction into the field due to their uncertain genetic stability (Slazak et al, 2015a(Slazak et al, , 2015b.…”

Section: Introductionmentioning

confidence: 99%

Low Genetic Diversity of Declining Viola uliginosa (Violaceae) at its Southern Range Limits in Poland

Paul

Cieślak

Ronikier

et al. 2016

Acta Biologica Cracoviensia S. Botanica

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Viola uliginosa (bog violet) is a declining species throughout its range due to -mostly anthropogenic -drying out of the wet habitats it occupies. Using AFLP markers, we aimed to estimate the genetic diversity in Polish populations, that may give an insight into the situation of plant populations facing rapid loss of natural habitats. Bog violet from several dispersed Polish populations is generally characterized by very low genetic diversity (H T = 0.048), even lower than several other endangered violets; therefore, we suggest that it should preserve at least EN rank in the red lists/red data books. The mean gene diversity within all populations (H S ) was much lower than gene diversity (G ST ) between populations (0.020 versus 0.583, respectively) which supports the prevalence of clonal propagation of the species (mainly by stolons) but may also point to some significance of autogamy in cleisto-and chasmogamous flowers. A high F ST value and the Mantel test for all populations revealed significant isolation by distance. Geographically neighboring pairs of populations formed genetic clusters supported by all (in the case of two closest populations) or most statistical analyses applied. Special attention should be paid to the locus classicus of the species in Rząska, consisting of a small number of individuals, forming a genetically distinct group, revealing very low gene diversity (H j = 0.009) and the longest genetic distance to the remaining populations. Our results can contribute to planning future protection measures for the species at this and other locations. Genetic structure of the studied populations suggests local affinities of populations but does not generally support hypothesized recent continuity of V. uliginosa range along the river valleys of southern Poland; this view may, however, be altered with widening of the scope of studied populations and chosen molecular markers.

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Exogenous plant hormones and cyclotide expression in Viola uliginosa (Violaceae)

Cited by 32 publications

References 49 publications

How Does the Sweet Violet (Viola odorata L.) Fight Pathogens and Pests – Cyclotides as a Comprehensive Plant Host Defense System

How Does the Sweet Violet (Viola odorata L.) Fight Pathogens and Pests – Cyclotides as a Comprehensive Plant Host Defense System

Unveiling the diversity of cyclotides by combining peptidome and transcriptome analysis

Low Genetic Diversity of Declining Viola uliginosa (Violaceae) at its Southern Range Limits in Poland

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