Correlative analysis of Mycosphaerella graminicola pathogenicity and cell wall-degrading enzymes produced in vitro: the importance of xylanase and polygalacturonase

2007 ◽  
Vol 56 (1) ◽  
Author(s):  
M.-N. Douaiher ◽  
E. Nowak ◽  
R. Durand ◽  
P. Halama ◽  
Ph. Reignault
1990 ◽  
Vol 38 (3B) ◽  
pp. 407-422
Author(s):  
A. Steg ◽  
S.F. Spoelstra ◽  
J.M. van der Meer ◽  
V.A. Hindle

A total of 50 grass silages were tested in digestibility trials using Texel wethers. The feed silages were wilted of varying DM contents and treated with cell-wall degrading enzymes. The accuracy of feed evaluation was studied using laboratory analyses, including cell-wall analyses, incubation in vitro with rumen fluid and the enzymic procedure. A comparison was made between these results and the current and recently suggested procedures for prediction of digestibility of grass silage. (Abstract retrieved from CAB Abstracts by CABI’s permission)


2014 ◽  
Vol 1010-1012 ◽  
pp. 1161-1164
Author(s):  
Yan Qin Zhao ◽  
Yuan Hua Wu ◽  
Xiu Xiang Zhao ◽  
Meng Nan An ◽  
Jian Guang Chen ◽  
...  

Rhizoctonia solaniKühn is a causal pathogen responsible for many types of plant disease worldwide and a major soilborne fungal pathogen that severely impairs yield and quality of tobacco worldwide. Activities, pathogenicity of the cell wall-degrading enzymes produced by theRhizoctoniasolanifrom tobacco target spot disease both in liquid medium and in tobacco tissue were studied. The result showed thatR.solanifrom tobacco can produce pectinase and cellulase both in vitro and vivo, and the activity of PG and PMG was the highest in vitro. The activity of Cx and β-glucosidase was the highest in vivo, and enzyme production ability of strong pathogenicity strains is stronger than the weak pathogenicity strains in vitro.


1996 ◽  
Vol 74 (9) ◽  
pp. 1407-1415 ◽  
Author(s):  
Mohamed S. El-Abyad ◽  
Amira M. Abu-Taleb ◽  
Tarek Abdel-Mawgood

Pyradur applied to soil at 0.6–2.4 µg∙g−1 active ingredients suppressed infection of three sugarbeet cultivars by Rhizoctonia solani and Sclerotium rolfsii. In the absence of Pyradur, R. solani was more virulent than S. rolfsii against 'Raspoly' and 'TOP', whereas S. rolfsii was more virulent than R. solani against ‘Tribel’. Virulence was directly correlated with the activities of cell wall degrading enzymes produced by mese pathogens in vivo and on cell walls in vitro. Reduced virulence of R. solani and S. rolfsii under Pyradur stress was due to decreased inoculum potential of the two pathogens at the utilized concentrations of herbicide in situ and to reduced production of cell wall degrading enzymes in vitro and in host tissues. In addition, shifts in the pH of cell wall amended media, because of changes in the nature of metabolic products of the pathogens under Pyradur stress, suggest possible repression or stimulation of the activity of the enzymes involved in degradation in vivo, of which cellulase and polygalacturonase are favoured by acid conditions, and galactanase, mannase, and pectate lyase are favoured by alkaline conditions. Keywords: sugarbeet, Rhizoctonia solani, Sclerotium rolfsii, Pyradur, metolachlor, chloridazon, growth activities, pathogenicity, virulence, cell wall enzymes.


2021 ◽  
Author(s):  
Louise Emma Crozier ◽  
Jacqueline Marshall ◽  
Ashleigh Holmes ◽  
Kathryn Wright ◽  
Yannick Rossez ◽  
...  

Arabinose is a major plant aldopentose in the form of arabinans complexed in cell wall polysaccharides or glycoproteins (AGP), but comparatively rare as a monosaccharide. L-arabinose is an important bacterial metabolite, accessed by pectolytic microorganisms such as Pectobacterium atrosepticum via pectin and hemicellulose degrading enzymes. However, not all plant-associated microbes encode cell wall degrading enzymes, yet can metabolise L-arabinose, raising questions about their use of and access to the glycan in plants. Therefore, we examined L-arabinose metabolism in the food-borne pathogen Escherichia coli O157:H7 (isolate Sakai) during its colonisation of plants. L-arabinose metabolism (araBA) and transport (araF) genes were activated at 18 C in vitro by L-arabinose and expressed over prolonged periods in planta. Although deletion of araBAD did not impact the colonisation ability of E. coli O157:H7 (Sakai) on plants, araA was induced on exposure to spinach cell wall polysaccharides. Furthermore, debranched and arabinan oligosaccharides induced ara metabolism gene expression in vitro, and stimulated modest proliferation, while immobilised pectin did not. Thus, E. coli O157:H7 (Sakai) can utilise pectin/AGP-derived L-arabinose as a metabolite, but differs fundamentally in ara gene organisation, transport and regulation from the related pectinolytic species P. atrosepticum, reflective of distinct plant-associated lifestyles.


2021 ◽  
Author(s):  
Abhijeet Roy ◽  
Barsha Kalita ◽  
Aiswarya Jayaprakash ◽  
Annamalai Arunachalam ◽  
Lakshmi PTV

Abstract Fusarium oxysporum f. sp. lycopersici (Fol), a causal organism of Fusarium wilt in the tomato plant, secretes cell wall degrading enzymes, also known as carbohydrate-active enzymes (CAZymes). These are crucial during colonization and pathogenesis, as evidenced by several proteomic studies, revealing the importance of these CAZymes in virulence and pathogenicity. However, few of them have been done in-planta, exhibiting differences in the expression of these cell wall degrading enzymes compared to in-vitro studies. Therefore, to explore the CAZymes involved in pathogenesis while residing in the host plant, an in-planta (xylem sap) proteomics of a susceptible tomato variety affected with Fol was done. Most of these CAZymes belonged to the hydrolase and oxidoreductase families having no significant homology with tomato proteins. Nearly 90% of them were predicted to be soluble and extracellular. The core CAZymes families with interactional evidence identified were AA3, GH3, GH18, GH20, GH28, GH43, GH47, GH55 and CE8. Thus, apart from annotating some of the hypothetical proteins to be CAZymes, the study sheds light on CAZymes families that may have a role in the pathogenesis and survival of this fungus in the susceptible tomato plant.


2008 ◽  
Vol 48 (4) ◽  
pp. 437-451 ◽  
Author(s):  
Theerthagiri Anand ◽  
Ramanujam Bhaskaran ◽  
Thiruvengadam Gandhi Karthikeyan ◽  
Manikam Rajesh ◽  
Govindasamy Senthilraja

Production of Cell Wall Degrading Enzymes and Toxins byColletotrichum CapsiciandAlternaria AlternataCausing Fruit ROT of ChilliesThe virulent isolates ofColletotrichum capsiciandAlternaria alternataproduced more cellulolytic enzymesviz., C1and Cxin vitrothan the avirulent ones and the activity of these enzymes increased with the increase in age of culture. The virulent isolates ofC. capsiciandA. alternataproduced more pectinolytic enzymes (macerating enzymes, pectin methyl esterase and endo polygalacturonase) than the avirulent ones. All the pectinolytic enzymes were highly active in 10-day-old culture and the activities decreased with the increase of culture age. Whereas the activity of enzymes produced by avirulent isolate of pathogens did not decrease and these enzyme activities increased with the increase in the age of culture. These pathogens also produced nonspecific toxic metabolites in culture filtrate which reduced seed germination, root length, shoot length and vigour index of the seedlings of chilli, rice, mungbean, maize, cotton, groundnut, okra, egg plant, cucumber and tomato. The toxins of the pathogens reduced seed germination and caused mortality of chilli seedlings in pot culture. The toxins also produced phytotoxic symptoms in the treated ripe and green chilli fruits and leaves.


Sign in / Sign up

Export Citation Format

Share Document