References of "Kwasiborski, Anthony"
     in
Bookmark and Share    
Full Text
See detailBiocontrol proteomics:Implication of the pentoses phosphates pathway in the antagonist effect of Pichia anomala against Botrytis cinerea on apple
Kwasiborski, Anthony ULg; Renaut, Jenny; Lepoivre, Philippe ULg et al

Poster (2011, September 21)

The growing interest of the consumers for the wholesome food and the protection of the environment as well as the development of resistant pathogens to pesticides, stimulate the interest of growers to ... [more ▼]

The growing interest of the consumers for the wholesome food and the protection of the environment as well as the development of resistant pathogens to pesticides, stimulate the interest of growers to apply biological control methods. Pichia anomala strain K was previously identified as an efficient biocontrol agent of the main apple pathogens, Botrytis cinerea and Penicillum expansum. Further study demonstrated the complexicity of the mode of action of P. anomala against B. cinerea. A cDNA-AFLP and gene disruption study revealed implication of exo-β-1,3-glucanases in the mode of action of P. anomala strain Kh6 (a haploid form of P. anomala strain K displaying the same biocontrol properties). However, these studies suggested also implication of other factors. The present study aims to increase our knowledge of the mode of action of P. anomala strain Kh6 against B. cinerea using an in situ approach allowing the triple interaction, host/pathogen/antagonist and the proteomic tool allowing to study the ultime expression of the genome without a priori. One 50mm wound per apple were covered by a membrane and inoculated by a P. anomala suspension then by B. cinerea or not. Samples were collected during the exponential and stationary phase to identify the early and later responses to the presence of B. cinerea. After extraction, proteins were separated on 2-D gels. Spots influenced by the presence of B. cinerea in exponential and stationary phases were identified by MALDI-ToF. One hundred five and sixty spots of proteins were influenced by the presence of B. cinerea in exponential and stationary phases respectively. In exponential phase, P. anomala Kh6 in absence of B. cinerea uses mainly the glycolysis pathway, whereas in presence of pathogen, it orientates its energetic metabolism to the oxidative phosphorylation and sets up the pentose phosphate pathway. Thanks to this new orientation, P. anomala Kh6 probably obtains energy and nucleic acids allowing to colonize the wound as fast as in absence of B. cinerea and prevents the use of nutrients by the pathogen. In stationary phase, no differences in the P. anomala Kh6 energetic metabolism, in absence and in presence of B. cinerea were observed. During that phase, P. anomala Kh6 seems to use the alcoholic fermentation in order to face the nutrients impoverishment of the substrate. [less ▲]

Detailed reference viewed: 37 (1 ULg)
Full Text
See detailBiocontrol proteomics:Implication of the pentoses phosphates pathway in the antagonist effect of Pichia anomala against Botrytis cinerea on apple.
Kwasiborski, Anthony ULg; renaut, Jenny; Delaplace, Pierre ULg et al

Conference (2011, August 31)

Pichia anomala strain K was previously identified as an efficient biocontrol agent of the apple pathogen, Botrytis cinerea. Further study demonstrated the complexicity of the mode of action of P. anomala ... [more ▼]

Pichia anomala strain K was previously identified as an efficient biocontrol agent of the apple pathogen, Botrytis cinerea. Further study demonstrated the complexicity of the mode of action of P. anomala against B. cinerea. A molecular study revealed implication of exo-β-1,3-glucanases in the mode of action of P. anomala but suggested implication of other factors. The present study aims to increase our knowledge of the mode of action of P. anomala strain Kh6 against B. cinerea using an in situ approach allowing interactions between organisms, and the proteomic tool allowing to study the ultime expression of the genome. One wound per apple were covered by a membrane and inoculated by P. anomala then by B. cinerea or not. Samples were collected at different incubation times to identify the responses of P. anomala to the presence of B. cinerea. After extraction, proteins were separated on 2-D gels. Spots influenced were identified by MALDI-ToF. In exponential phase, P. anomala Kh6 orientates its energetic metabolism from the glycolysis to the oxidative phosphorylation and sets up the pentose phosphate pathway. Thanks to this new pathway, P. anomala probably obtains energy and nucleic acids allowing to colonize the wound as fast as in absence of B. cinerea. In stationary phase, no differences in the P. anomala energetic metabolism, in absence and in presence of B. cinerea were observed. During that phase, P. anomala seems to use the alcoholic fermentation in order to face the nutrients impoverishment of the substrate. [less ▲]

Detailed reference viewed: 60 (3 ULg)
Full Text
See detailIn situ proteome study of Pichia anomala strain K, an antagonist of the apple pathogen Botrytis cinerea
Kwasiborski, Anthony ULg; Renaut, Jenny; Delaplace, Pierre ULg et al

Conference (2011, May 24)

Postharvest fungal pathogens, mainly Botrytis cinerea, Penicillum expansum and Gloeosporium spp., annually cause 5-20% losses of fruit. Control measures against these diseases include chemical fungicide ... [more ▼]

Postharvest fungal pathogens, mainly Botrytis cinerea, Penicillum expansum and Gloeosporium spp., annually cause 5-20% losses of fruit. Control measures against these diseases include chemical fungicide applications, but the development of resistant fungal explains the growing interest for biological control. Pichia anomala strain K was previously identified as an efficient antagonist of pathogens on apples. Indeed, the percentage of protection of P.anomala against B.cinerea reached from 90 to 100% on apple wounds according to the experimental conditions. Microbiological, biochemical and molecular approaches demonstrated the implication of exo-β-1,3-glucanases in the mechanism of action of P.anomala. However, study of these mechanisms could be improved by observations under natural infection conditions in order to take into account the tripartite interactions host/antagonist/pathogen. The proteomic tool allowed an overview of process implicated in the antagonism against B.cinerea in such conditions. One 50mm wound per apple were covered by a membrane and inoculated by a P.anomala suspension then by B.cinerea or not. Samples were collected during the exponential and stationary phase to identify the early and later responses to the presence of B.cinerea. After extraction, proteins were separated on 2DE gels. Spots influenced by the presence of B.cinerea in exponential and stationary phases were identified by MALDI-ToF. One hundred five and sixty spots of proteins were influenced by the presence of B.cinerea in exponential and stationary phase respectively. In exponential phase, influenced proteins were implicated in the different steps of the proteins biosynthesis: amino acid synthesis, translation or mRNA maturation and in energy synthesis. On the other hand, in stationary phase, influenced proteins were mainly implicated in energy metabolic pathway: glycolysis, alcoholic fermentation or gluconeogenesis. The presence of B.cinerea seemed to induce a slowdown in the metabolism of P.anomala without influenced its growth. Further studies have to be realized to understand the complexity of these modes of action. [less ▲]

Detailed reference viewed: 40 (1 ULg)
Full Text
See detailEvaluation of two protein extraction protocols for Pichia anomala proteome analysis.
Bajji, Mohammed; Delaplace, Pierre ULg; Mauro, Sergio et al

Poster (2009, May 19)

Pichia anomala (strain Kh6) was isolated from the surface of apple fruits and selected for its high and reliable biocontrol activity against Botrytis cinerea and Penicillium expansum. Its main modes of ... [more ▼]

Pichia anomala (strain Kh6) was isolated from the surface of apple fruits and selected for its high and reliable biocontrol activity against Botrytis cinerea and Penicillium expansum. Its main modes of action have until now been studied using essentially microbiological and molecular approaches. The study continues now using the proteomic approach and considering the in situ P. anomala/B. cinerea/apple interaction. Two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) is one of the most powerful tools used for proteomic analysis. It combines two sequential separation steps, the first dimension via isoelectric focusing (IEF) and the second one by SDS PAGE. Although recent advances in 2-D PAGE, the extraction of the whole proteome and the removal of interfering contaminants still limit its application. Sample preparation constitutes indeed a critical influential step for IEF which in turn affects 2-D gel quality. The objective of the present work was thus to develop an effective protein extraction protocol designed for 2-D PAGE analysis of the proteome of P. anomala strain Kh6. As a starting point, two contrasting protein extraction protocols were chosen to be evaluated in terms of protein yield and one-dimensional (1-D) SDS PAGE and 2-D PAGE gel patterns. The first protocol uses a urea/thiourea-based lysis buffer whereas the second protocol utilizes a hot SDS-based lysis buffer with an additional precipitation step. The comparison model used consisted of apples treated with strain Kh6 alone (K) and apples first treated with Kh6 and then inoculated with B. cinerea conidia (KB). Growth kinetics of strain Kh6 on wounded apples was determined and found to be not affected by the presence of B. cinerea conidia. Proteins were extracted from yeast pellets collected at both the exponential and stationary phases of strain Kh6 growth on apples. The evaluation of both extraction protocols indicates that more proteins were extracted with the SDS protocol and, according to 1-D assays, higher molecular weight proteins were obtained with the ‘urea/thiourea’ protocol and, regardless of the protocol used, more bands were obtained during the exponential phase. 2-D assays are currently underway and the corresponding results will be presented. [less ▲]

Detailed reference viewed: 53 (1 ULg)