scholarly journals Unravelling the role of alcohol copper radical oxidases in fungal plant pathogens

2021 ◽  
Author(s):  
Bastien Bissaro ◽  
Sayo Kodama ◽  
Hayat Hage ◽  
David Ribeaucourt ◽  
Mireille Haon ◽  
...  
Keyword(s):  
Plant Pathogens ◽  
Crop Protection ◽  
Redox Partner ◽  
Fungal Plant Pathogens ◽  
Plant Cuticles ◽  
Penetration Ability ◽  
Molecular Signals

Abstract Copper radical oxidases (CRO) form a class of enzymes with a longstanding history encompassing diverse substrate specificities. While the biological function of most CROs remains unknown, we observed that CROs active on aliphatic alcohols are found only in fungal plant pathogens. Here, we unveil the role of these CROs and the identity of their natural redox partner, a haem-iron peroxidase. Combining multiscale approaches, we report that Colletotrichum and Magnaporthe appressoria (specialized cells that puncture the plant cuticles) co-secrete this pair of metalloenzymes early during penetration. We show in vivo that mutant appressoria lacking either or both enzymes have impaired penetration ability and pathogenicity. We reveal in vitro a finely-tuned enzyme interplay is responsible for the oxidation of plant cuticular long-chain alcohols into aldehyde products, suggested to act as key molecular signals in the fungal infection machinery. Our results open new avenues to design oxidase-specific inhibitors as anti-penetrants for crop protection.

Regulation and Dynamics of Gene Expression During the Life Cycle of Fusarium graminearum

2020 ◽  
Vol 110 (8) ◽  
pp. 1368-1374
Author(s):  
Elizabeth K. Brauer ◽  
Rajagopal Subramaniam ◽  
Linda J. Harris
Keyword(s):  
Gene Expression ◽  
Fusarium Graminearum ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Transcriptional Profiling ◽  
Fungal Plant Pathogens ◽  
Essential Components ◽  
Host Infection

Fungal pathogens survive harsh environments and overcome physical, temporal, and chemical barriers to colonize their hosts and reproduce. Fusarium graminearum was one of the first fungal plant pathogens for which transcriptomic tools were developed, making analysis of gene expression a cornerstone approach in studying its biology. The analysis of gene expression in diverse in vitro conditions and during infection of different cereal crops has revealed subsets of both unique and shared transcriptionally regulated genes. Together with genetic studies, these approaches have enhanced our understanding of the development and infection cycle of this economically important pathogen. Here, we will outline recent advances in transcriptional profiling during sporogenesis, spore germination, vegetative growth, and host infection. Several transcriptional regulators have been identified as essential components in these responses and the role of select transcription factors will be highlighted. Finally, we describe some of the gaps in our understanding of F. graminearum biology and how expression analysis could help to address these gaps.

scholarly journals Role of Major Glucosinolates in the Defense of Kale Against Sclerotinia sclerotiorum and Xanthomonas campestris pv. campestris

2019 ◽  
Vol 109 (7) ◽  
pp. 1246-1256 ◽  
Author(s):  
Pari Madloo ◽  
Margarita Lema ◽  
Marta Francisco ◽  
Pilar Soengas
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Xanthomonas Campestris ◽  
Plant Pathogens ◽  
Infection Process ◽  
Wide Range ◽  
Bacteria And Fungi ◽  
Xanthomonas Campestris Pv Campestris

Glucosinolates (GSLs) are secondary metabolites present in Brassicaceae species implicated in their defense against plant pathogens. When a pathogen causes tissue damage, the enzyme myrosinase hydrolyzes GSLs into diverse products that exhibit antimicrobial activity against a wide range of bacteria and fungi in vitro. It was demonstrated that modulation of GSL content in vivo affects plant resistance to infection by pathogens in Arabidopsis. However, the roles of specific metabolites and how they interact with pathogens are poorly understood in Brassica crops. We previously developed a set of populations of Brassica oleracea var. acephala L. (kale) differing in content of three GSLs: the aliphatics sinigrin (2-propenyl [SIN]) and glucoiberin (3-methylsulphinylpropyl [GIB]) and the indolic glucobrassicin (3-indolylmethyl [GBS]). These populations can be used to study the effects of major GSLs in kale, with the advantage that genotypes within each selection have the same genetic background. This research aimed to explore the role of SIN, GIB, and GBS in the defense of kale against the necrotrophic fungus Sclerotinia sclerotiorum and the bacterium Xanthomonas campestris pv. campestris. Results showed that increasing the amount of a particular GSL did not always result in disease resistance. The effects of GSLs were apparently dependent on the pathogen and the type of GSL. Thus, the aliphatic SIN was inhibitory to infection by S. sclerotiorum and the indolic GBS was inhibitory to infection by X. campestris pv. campestris. Other factors, including the quantity and proportion of other metabolites modified during the pathogen infection process, could also modulate the degree of inhibition to the pathogen.

scholarly journals The role of silicon (Si) in increasing plant resistance against fungal diseases

2016 ◽  
Vol 9 (1) ◽  
pp. 1-15 ◽  
Author(s):  
N. Sakr
Keyword(s):  
Plant Resistance ◽  
Plant Pathogens ◽  
Pathogenic Fungi ◽  
Fungal Diseases ◽  
Inhibitory Effects ◽  
Fungal Plant Pathogens ◽  
Silicon Nutrition ◽  
The Relationship

Summary The use of silicon (Si) in agriculture has attracted a great deal of interest from researchers because of the numerous benefits of this element to plants. The use of silicon has decreased the intensity of several diseases in crops of great economic importance. In this study, the relationship between silicon nutrition and fungal disease development in plants was reviewed. The current review underlines the agricultural importance of silicon in crops, the potential for controlling fungal plant pathogens by silicon treatment, the different mechanisms of silicon-enhanced resistance, and the inhibitory effects of silicon on plant pathogenic fungi in vitro. By combining the data presented in this paper, a better comprehension of the relationship between silicon treatments, increasing plant resistance, and decreasing severity of fungal diseases could be achieved.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

Anti-obesity role of Aster glehni extract: in vivo and in vitro effects

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
HM Lee ◽  
TG Ahn ◽  
CW Kim ◽  
HJ An
Keyword(s):  
In Vitro Effects

A Molecular Approach to Immunoscintigraphy: A Study of the T-Antigen Conformation on the Surface of Tumors

1987 ◽  
Vol 26 (01) ◽  
pp. 1-6 ◽  
Author(s):  
S. Selvaraj ◽  
M. R. Suresh ◽  
G. McLean ◽  
D. Willans ◽  
C. Turner ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Cell ◽  
T Antigen ◽  
Human Carcinomas ◽  
Animal Tumor ◽  
Synthetic Antigens

The role of glycoconjugates in tumor cell differentiation has been well documented. We have examined the expression of the two anomers of the Thomsen-Friedenreich antigen on the surface of human, canine and murine tumor cell membranes both in vitro and in vivo. This has been accomplished through the synthesis of the disaccharide terminal residues in both a and ß configuration. Both entities were used to generate murine monoclonal antibodies which recognized the carbohydrate determinants. The determination of fine specificities of these antibodies was effected by means of cellular uptake, immunohistopathology and immunoscintigraphy. Examination of pathological specimens of human and canine tumor tissue indicated that the expressed antigen was in the β configuration. More than 89% of all human carcinomas tested expressed the antigen in the above anomeric form. The combination of synthetic antigens and monoclonal antibodies raised specifically against them provide us with invaluable tools for the study of tumor marker expression in humans and their respective animal tumor models.

THYROID STIMULATORS AND THYROID STIMULATION

1971 ◽  
Vol 66 (3) ◽  
pp. 558-576 ◽  
Author(s):  
Gerald Burke
Keyword(s):  
Regulatory System ◽  
Control Site ◽  
Thyroid Cell ◽  
Primary Control ◽  
Physico Chemical ◽  
Site Of Action ◽  
Long Acting

ABSTRACT A long-acting thyroid stimulator (LATS), distinct from pituitary thyrotrophin (TSH), is found in the serum of some patients with Graves' disease. Despite the marked physico-chemical and immunologic differences between the two stimulators, both in vivo and in vitro studies indicate that LATS and TSH act on the same thyroidal site(s) and that such stimulation does not require penetration of the thyroid cell. Although resorption of colloid and secretion of thyroid hormone are early responses to both TSH and LATS, available evidence reveals no basic metabolic pathway which must be activated by these hormones in order for iodination reactions to occur. Cyclic 3′, 5′-AMP appears to mediate TSH and LATS effects on iodination reactions but the role of this compound in activating thyroidal intermediary metabolism is less clear. Based on the evidence reviewed herein, it is suggested that the primary site of action of thyroid stimulators is at the cell membrane and that beyond the(se) primary control site(s), there exists a multifaceted regulatory system for thyroid hormonogenesis and cell growth.

THE ROLE OF POLYETHYLENIMINE IN ENHANCING PERFORMANCE OF GLUTAMATE BIOSENSORS

2018 ◽  
Vol 8 (3) ◽  
pp. 36-41
Author(s):  
Diep Do Thi Hong ◽  
Duong Le Phuoc ◽  
Hoai Nguyen Thi ◽  
Serra Pier Andrea ◽  
Rocchitta Gaia
Keyword(s):  
First Generation ◽  
Good Reproducibility ◽  
Complex Matrices ◽  
Long Term Stability ◽  
In Vitro Characterization ◽  
Glutamate Oxidase

Background: The first biosensor was constructed more than fifty years ago. It was composed of the biorecognition element and transducer. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples Glutamate is important biochemicals involved in energetic metabolism and neurotransmission. Therefore, biosensors requires the development a new approach exhibiting high sensibility, good reproducibility and longterm stability. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples. The aims of this work: To find out which concentration of polyethylenimine (PEI) exhibiting the most high sensibility, good reproducibility and long-term stability. Methods: We designed and developed glutamate biosensor using different concentration of PEI ranging from 0% to 5% at Day 1 and Day 8. Results: After Glutamate biosensors in-vitro characterization, several PEI concentrations, ranging from 0.5% to 1% seem to be the best in terms of VMAX, the KM; while PEI content ranging from 0.5% to 1% resulted stable, PEI 1% displayed an excellent stability. Conclusions: In the result, PEI 1% perfomed high sensibility, good stability and blocking interference. Furthermore, we expect to develop and characterize an implantable biosensor capable of detecting glutamate, glucose in vivo. Key words: Glutamate biosensors, PEi (Polyethylenimine) enhances glutamate oxidase, glutamate oxidase biosensors

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