Search results for "Chitin"

Co-Infections by Fusarium circinatum and Phytophthora spp. on Pinus radiata: Complex Phenotypic and Molecular Interactions

2021

13 Pág. Instituto de Ciencias Forestales (ICIFOR)

Molecular Topology QSAR Strategy for Crop Protection: New Natural Fungicides with Chitin Inhibitory Activity

2020

Nowadays, crop protection is a major concern and how to proceed is a delicate point of contention. New products must be safe and ecofriendly in accordance with the actual legislation. In this context, we present a quantitative structure-activity relationship strategy based on molecular topology as a tool for generating natural products as potential fungicides following a mechanism of action based on the synthesis of chitin inhibition (chitinase inhibition). Two discriminant equations using statistical linear discriminant analysis were used to identify three potential candidates (1-methylxanthine, hematommic acid, and antheraxanthin). The equations showed accuracy and specificity levels abov…

VALUTAZIONE DELLA TOLLERANZA ALLO STRESS SALINO DI DUE SPECIE DA TAPPETO ERBOSO TRATTATE CON APPLICAZIONI FOGLIARI DI GLICINBETAINA ( OSMOREGOLATORE …

2011

Response of yeast cells to high glucose involves molecular and physiological differences when compared to other osmostress conditions.

2015

Yeast cells can be affected by several causes of osmotic stress, such as high salt, sorbitol or glucose concentrations. The last condition is particularly interesting during natural processes where this microorganism participates. Response to osmostress requires the HOG (High Osmolarity Glycerol) pathway and several transcription factors, including Hot1, which plays a key role in high glucose concentrations. In this work, we describe how the yeast response to osmotic stress shows differences in accordance with the stress agent responsible for it. Compared with other conditions, under high glucose stress, delocalization of MAPK (Mitogen-Activated Protein Kinase) Hog1 is slower, induction of …

Initial steps of wall protoplast regeneration in Candida albicans

1997

Summary Cell wall regeneration of individual Candida albicans yeast and mycelial protoplasts was studied with confocal and electron microscopy using polyclonal antibodies and leetins. Quantitative measurements of the fluorescence emitted by individual protoplasts during the process of regeneration indicate that chitin is the first polymer to be laid down, whereas β(1,3)- and β(1,6)glucan are incorporated at a later stage. Mannoproteins were found on the surface of fresh protoplasts and those newly synthesized were then deposited with time. During the first steps of wall regeneration, the proteins that interacted covalently with chitin or glucan were different, but the same species were foun…

Loss of virulence in Ustilago maydis by Umchs6 gene disruption

2003

A gene encoding a sixth chitin synthase (Umchs6, sequence GenBank accession No. AF030554) from the plant pathogenic hemibasidiomycete Ustilago maydis (DC.) Cda. was isolated and characterized. The predicted protein is 1103 amino acids in length with a calculated molecular mass of 123.5 kDa. a2b2 null mutants were obtained by substitution of a central fragment of the Umchs6 gene with the hygromycin resistance cassette, and a1b1 null mutants were obtained by genetic recombination in plants of an a2b2Δch6 and a wild-type a1b1 strain. The mutation had no effect on the dimorphic transition in vitro or on mating, and growth rate of the mutants was only slightly reduced. On the other hand, they di…

Paenibacillus larvae Chitin-Degrading Protein PlCBP49 Is a Key Virulence Factor in American Foulbrood of Honey Bees

2014

Paenibacillus larvae, the etiological agent of the globally occurring epizootic American Foulbrood (AFB) of honey bees, causes intestinal infections in honey bee larvae which develop into systemic infections inevitably leading to larval death. Massive brood mortality might eventually lead to collapse of the entire colony. Molecular mechanisms of host-microbe interactions in this system and of differences in virulence between P. larvae genotypes are poorly understood. Recently, it was demonstrated that the degradation of the peritrophic matrix lining the midgut epithelium is a key step in pathogenesis of P. larvae infections. Here, we present the isolation and identification of PlCBP49, a mo…

Regeneration of the cell wall in protoplasts of Candida albicans. A cytochemical study using wheat germ agglutinin and concanavalin A.

1988

To assess the dynamics of synthesis of the wall by regenerating Candida albicans protoplasts deposition of chitin and mannoproteins were investigated ultrastructurally using wheat germ agglutinin conjugated with either horseradish peroxidase or colloidal gold, and Concanavalin A coupled to ferritin respectively. Freshly prepared protoplasts lacked wheat germ agglutinin receptor sites but after 1-2 h of regeneration, they were detected. After 4-5 h of regeneration, the cell wall showed a discrete structure which was only labelled with wheat germ agglutinin in thin sections. At this stage of regeneration the outermost layer of the wall was labelled with clusters of Concanavalin A-ferritin par…

Influence of bentonite fining on protein composition in wine

2017

Abstract Bentonite is the only fining agent which can stabilize wine and prevent protein haze formation after bottling. Currently many approaches are used to find an alternative because of bentonite's negative influence on color and aroma compounds. Nevertheless, the interaction of bentonite with wine proteins is not fully understood. Therefore, we analyzed the influence of a NaCa-combined bentonite on the protein content and composition of different wines showing a partial selectivity on protein adsorption. For example, glycosylated proteins were not removed by bentonite in notable amounts. Performing mass spectrometry we were able to demonstrate that 96% of class IV chitinase was adsorbed…

The shell matrix and microstructure of the Ram's Horn squid: Molecular and structural characterization.

2020

20 pages; International audience; Molluscs are one of the most diversified phyla among metazoans. Most of them produce an external calcified shell, resulting from the secretory activity of a specialized epithelium of the calcifying mantle. This biomineralization process is controlled by a set of extracellular macromolecules, the organic matrix. In spite of several studies, these components are mainly known for bivalves and gastropods. In the present study, we investigated the physical and biochemical properties of the internal planispiral shell of the Ram's Horn squid Spirula spirula. Scanning Electron Microscope investigations of the shell reveal a complex microstructural organization. The…