scholarly journals Mode of action of a fatty acid-based natural product to control Botrytis cinerea in grapes

2014 ◽  
Vol 116 (4) ◽  
pp. 967-979 ◽  
Author(s):  
C. Calvo-Garrido ◽  
P.A.G. Elmer ◽  
F.J. Parry ◽  
I. Viñas ◽  
J. Usall ◽  
...  
Plants ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 141
Author(s):  
Helena Santos ◽  
Catarina Augusto ◽  
Pedro Reis ◽  
Cecília Rego ◽  
Ana Cristina Figueiredo ◽  
...  

The aroma of grapes is cultivar dependent and is influenced by terroir, vineyard practices, and abiotic and biotic stresses. Trincadeira is a non-aromatic variety associated with low phenolic content and high sugar and organic acid levels. This cultivar, widely used in Portuguese wines, presents high susceptibility to Botrytis cinerea. This work aimed to characterise the volatile profile of Trincadeira grapes and how it changes under infection with B. cinerea. Thirty-six volatile organic compounds were identified, from different functional groups, namely alcohols, ester acetates, fatty acid esters, fatty acids, aldehydes, and products of the lipoxygenase pathway. Both free and glycosidic volatile organic compounds were analysed by Gas Chromatography and Gas Chromatography coupled to Mass Spectrometry for component quantification and identification, respectively. A multivariance analysis showed a clear discrimination between healthy and infected grapes with 2-trans-hexenal and isoamyl-acetate among the compounds identified as negative and positive markers of infection, respectively. Ester acetates such as 2-phenylethyl acetate, isoamyl acetate, and 2-methylbutyl acetate were present in higher contents in infected samples, whereas the contents of several fatty acid esters, such as ethyl decanoate and ethyl dodecanoate, decreased. These data were integrated with quantitative PCR data regarding genes involved in volatile metabolism and showed up-regulation of a gene coding for Hydroperoxide Lyase 2 in infected grapes. Altogether, these changes in volatile metabolism indicate an impact on the grape quality and may be related to defence against B. cinerea. The presence/absence of specific compounds might be used as infection biomarkers in the assessment of Trincadeira grapes’ quality.


Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 147-147 ◽  
Author(s):  
G. W. Moorman ◽  
A.-S. Walker ◽  
S. May

Greenhouse-grown Heuchera plants, treated with fenhexamid (Decree, SePRO, Carmel, IN; FRAC group 17 hydroxyanilide), with active gray mold were submitted to the Penn State Plant Disease Clinic in December 2010 from a commercial operation in north-central Pennsylvania. Genetic and phenotypic analyses identified the isolate as Botrytis cinerea Pers. (teleomorph Botryotinia fuckeliana (de Bary) Whetzel), HydR3 phenotype (2) and not B. pseudocinerea (previously Botrytis group I) (4), naturally resistant to fenhexamid (phenotype HydR1) (1). While 0.2 μg of fenhexamid per ml or less is required to slow mycelial growth and germ tube elongation of sensitive isolates by 50% (EC50), the radial growth EC50 of the Heuchera isolate was approximately 2,000 μg of fenhexamid per ml in culture. Five cucumber seedlings receiving 25 μl of 0.1 M dextrose containing the label rate of Decree (1,800 μg/ml) on the growing tip were inoculated with colonized agar in the drop. Five check plants received 25 μl of 0.1 M dextrose. B. cinerea from silica gel storage since 1988 was also tested. This experiment was repeated three times. The 1988 isolate killed all fungicide-free but no fenhexamid-treated plants. The Heuchera isolate killed all fungicide-free and fenhexamid-treated plants within 4 days. To our knowledge, this is the first report of B. cinerea from a greenhouse in North America with fenhexamid resistance. Resistance occurs in U.S. fields (3). The Heuchera isolate's HydR3 resistance phenotype (2) has been detected in Germany, Japan, and France and has mutations affecting the 3-keto reductase protein, encoded by the erg27 gene, the specific target of fenhexamid and involved in Botrytis sterol biosynthesis. The Decree label states that it is to be used only twice on a crop before switching to a different mode of action. Greenhouses have resident Botrytis populations that are likely to be exposed to any fungicide applied in the structure. Growers should consider using fenhexamid only twice in a particular greenhouse, rather than on a particular crop, before switching to a different mode of action. References: (1) P. Leroux et al. Crop Prot. 18:687, 1999.(2) P. Leroux et al. Pest Manag. Sci. 58:876, 2002. (3) Z. Ma and T. J. Michailides. Plant Dis. 89:1083, 2005. (4) A.-S. Walker et al. Phytopathology 101:1433, 2011.


1963 ◽  
Vol 18 (1) ◽  
pp. 67-79 ◽  
Author(s):  
Wolfgang Heinen ◽  
Ingeborg V. D. Brand

1. Three fatty acid oxidizing enzymes, stearic and oleic acid oxidase as well as lipoxidase have been shown to be present in leaves of Gasteria verricuosa.2. By following the activity of these enzymes after injury we considered that they are involved in cutin synthesis which takes place at the wounded top of the leaf.3. Comparing the activity near the wounded part and the untreated inner sphere of the leaf lead to the conclusion that two of the oxidases (stearic and oleic oxidase) serve as substrate donors for lipoxydase by converting stearic into oleic and the latter into linoleic acid.4. Since the level of polyenic acids in leaves is high in comparison to saturated fatty acids, the activity of stearic and oleic oxidase only increases in the late phase of cutin synthesis, while lipoxydase is highly activated at the top directly after wounding and in the inner part of the leaf 3 - 4 weeks after cutin synthesis has started. At the same time pectinase shows its highest activity, suggesting that the formation of the pectic layer is secondary to the formation of cutin.5. Simultaneously to the enzymatic assays, cutin formation was followed by macro- and microscopic studies.6. The mode of action of lipoxydase and the interrelationship of the oxidizing enzymes in the formation of cutin are discussed and a formula for the structure of Gasteria cutin is given.7. According to the data presented here and the results obtained from literature, a possible scheme for cutin synthesis is given.


Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4147 ◽  
Author(s):  
Jens M. J. Nolsøe ◽  
Marius Aursnes ◽  
Yngve H. Stenstrøm ◽  
Trond V. Hansen

Recently, the identity of the marine hydrindane natural product (−)-mucosin was revised to the trans-fused structure 6, thereby providing a biogenetic puzzle that remains to be solved. We are now disseminating some of our insights with regard to the possible machinery delivering the established architecture. Aspects with regard to various modes of cyclization in terms of concerted versus stepwise processes are held up against the enzymatic apparatus known to be working on arachidonic acid (8). To provide a contrast to the tentative polyunsaturated fatty acid biogenesis, the structural pattern featured in (−)-mucosin (6) is compared to some marine hydrinane natural products of professed polyketide descent. Our appraisal points to a different origin and strengthens the hypothesis of a polyunsaturated fatty acids (PUFA) as the progenitor of (−)-mucosin (6).


Tetrahedron ◽  
2008 ◽  
Vol 64 (7) ◽  
pp. 1242-1249 ◽  
Author(s):  
Anna C. Giddens ◽  
Lone Nielsen ◽  
Helena I. Boshoff ◽  
Deniz Tasdemir ◽  
Remo Perozzo ◽  
...  

1962 ◽  
Vol 203 (4) ◽  
pp. 685-686 ◽  
Author(s):  
Shigetaka Ichikawa ◽  
Jiro Yamada

The minimum effective doses of oxytocin and arachidonic acid to produce contractions of pregnant and estrous rat uteri were determined. The pregnant rat uteri were significantly less sensitive to oxytocin and more sensitive to arachidonic acid than the estrous uteri. This mode of action of arachidonic acid on the uterine musculature indicates that the fatty acid may serve as an oxytocic substance for parturition.


2020 ◽  
Vol 86 (24) ◽  
Author(s):  
Zhibo Li ◽  
Reinder H. de Vries ◽  
Parichita Chakraborty ◽  
Chunxu Song ◽  
Xinghong Zhao ◽  
...  

ABSTRACT Nonribosomal peptides (NRPs) are a class of secondary metabolites usually produced by microorganisms. They are of paramount importance in different applications, including biocontrol and pharmacy. Brevibacillus spp. are a rich source of NRPs yet have received little attention. In this study, we characterize four novel bogorol variants (bogorols I to L, cationic linear lipopeptides) and four succilins (succilins I to L, containing a succinyl group that is attached to the Orn3/Lys3 in bogorols I to L) from the biocontrol strain Brevibacillus laterosporus MG64. Further investigation revealed that the bogorol family of peptides employs an adenylation pathway for lipoinitiation, different from the usual pattern, which is based on an external ligase and coenzyme A. Moreover, the formation of valinol was proven to be mediated by a terminal reductase domain and a reductase encoded by the bogI gene. Furthermore, succinylation, which is a novel type of modification in the family of bogorols, was discovered. Its occurrence requires a high concentration of the substrate (bogorols), but its responsible enzyme remains unknown. Bogorols display potent activity against both Gram-positive and Gram-negative bacteria. Investigation of their mode of action reveals that bogorols form pores in the cell membrane of both Gram-positive and Gram-negative bacteria. The combination of bogorols and relacidines, another class of NRPs produced by B. laterosporus MG64, displays a synergistic effect on different pathogens, suggesting the great potential of both peptides as well as their producer B. laterosporus MG64 for broad applications. Our study provides a further understanding of the bogorol family of peptides as well as their applications. IMPORTANCE NRPs form a class of secondary metabolites with biocontrol and pharmaceutical potential. This work describes the identification of novel bogorol variants and succinylated bogorols (namely, succilins) and further investigates their biosynthetic pathway and mode of action. Adenylation domain-mediated lipoinitiation of bogorols represents a novel pathway by which NRPs incorporate fatty acid tails. This pathway provides the possibility to engineer the lipid tail of NRPs without identifying a fatty acid coenzyme ligase, which is usually not present in the biosynthetic gene cluster. The terminal reductase domain (TD) and BogI-mediated valinol formation and their effect on the biological activity of bogorols are revealed. Succinylation, which is rarely reported in NRPs, was discovered in the bogorol family of peptides. We demonstrate that bogorols combat bacterial pathogens by forming pores in the cell membrane. We also report the synergistic effect of two natural products (relacidine B and bogorol K) produced by the same strain, which is relevant for competition for a niche.


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