The ACROPOLIS project: Its aims, achievements, and way forward
Klaveren, J.D. van; Kennedy, M.C. ; Moretto, A. ; Verbeke, W. ; Voet, H. van der - \ 2015
Food and Chemical Toxicology 79 (2015). - ISSN 0278-6915 - p. 1 - 4.
dopaminergic pc12 cells - azole fungicides - insecticides
Molecular characterization and functional analyses of ZtWor1, a transcriptional regulator of the fungal wheat pathogen Zymoseptoria tritici
Mirzadi Gohari, A. ; Mehrabi, R. ; Robert, O. ; Ince, I.A. ; Boeren, J.A. ; Schuster, M. ; Steinberg, G. ; Wit, P.J.G.M. de; Kema, G.H.J. - \ 2014
Molecular Plant Pathology 15 (2014)4. - ISSN 1464-6722 - p. 394 - 405.
phytopathogen mycosphaerella-graminicola - candida-albicans - sample preparation - septoria-tritici - azole fungicides - master regulator - gene - protein - resistance - cultivars
Zymoseptoria tritici causes the major fungal wheat disease septoria tritici blotch, and is increasingly being used as a model for transmission and population genetics, as well as host–pathogen interactions. Here, we study the biological function of ZtWor1, the orthologue of Wor1 in the fungal human pathogen Candida albicans, as a representative of a superfamily of regulatory proteins involved in dimorphic switching. In Z.¿tritici, this gene is pivotal for pathogenesis, as ZtWor1 mutants were nonpathogenic and complementation restored the wild-type phenotypes. In¿planta expression analyses showed that ZtWor1 is up-regulated during the initiation of colonization and fructification, and regulates candidate effector genes, including one that was discovered after comparative proteome analysis of the Z.¿tritici wild-type strain and the ZtWor1 mutant, which was particularly expressed in¿planta. Cell fusion and anastomosis occur frequently in ZtWor1 mutants, reminiscent of mutants of MgGpb1, the ß-subunit of the heterotrimeric G protein. Comparative expression of ZtWor1 in knock-out strains of MgGpb1 and MgTpk2, the catalytic subunit of protein kinase A, suggests that ZtWor1 is downstream of the cyclic adenosine monophosphate (cAMP) pathway that is crucial for pathogenesis in many fungal plant pathogens
Association mapping and meta-analysis: two complementary approaches for the detection of reliable Septoria tritici blotch quantitative resistance in bread wheat (Triticum aestivum L.)
Goudemand, E. ; Laurent, V. ; Duchalais, L. ; Tabib Ghaffary, M.S. ; Kema, G.H.J. ; Lonnet, P. ; Margalé, E. ; Robert, O. - \ 2013
Molecular Breeding 32 (2013)3. - ISSN 1380-3743 - p. 563 - 584.
genome-wide association - mycosphaerella-graminicola - winter-wheat - trait loci - dwarfing genes - plant height - population-structure - azole fungicides - qtl metaanalysis - hexaploid wheat
Septoria tritici blotch (STB), caused by the ascomycete Mycosphaerella graminicola, is one of the most ubiquitous and important diseases of bread wheat worldwide. The aim of this study was to identify markers linked to loci conferring resistance to STB from seven biparental populations. Linkage analysis, meta-analysis and association mapping were combined to identify robust quantitative trait loci (QTLs) for resistance. Linkage analysis led to the detection of 115 QTLs for resistance to STB and 66 QTLs linked to plant height and/or earliness. Meta-analysis clustered these 115 QTLs into 27 Meta-QTLs (MQTLs) of pathogen resistance, of which 14 were found to be linked to plant height and/or earliness. Both the relationship between dwarfing and susceptibility to STB and the significant negative correlation between earliness and STB symptoms were confirmed. Eleven loci were linked to STB resistance by association mapping using a general linear model and/or a mixed linear model, of which eight co-located with STB MQTLs and two co-located with individual QTLs. Associated markers located in MQTL regions enhanced the relevance of the results and validated the potential of an association mapping approach. With several biparental populations, meta-analysis is the most relevant form of genetic analysis study, but association mapping can be used as a validation method. Regions linked to resistance in both methods should be relevant for use in breeding programs for improving resistance to STB in wheat varieties. The main interest in comparing both approaches is to detect robust loci that will be functional in many genetic backgrounds rather than just in one or a few specific backgrounds
Genetic analysis of resistance to septoria tritici blotch in the French winter wheat cultivars Balance and Apache
Tabib Ghaffary, M.S. ; Robert, O. ; Laurent, V. ; Lonnet, P. ; Margalé, E. ; Lee, T.A.J. van der; Visser, R.G.F. ; Kema, G.H.J. - \ 2011
Theoretical and Applied Genetics 123 (2011)5. - ISSN 0040-5752 - p. 741 - 754.
mycosphaerella graminicola pathosystem - quantitative trait loci - fusarium head blight - azole fungicides - hydrogen-peroxide - host cultivars - chromosome 2d - plant height - spring wheat - linkage maps
The ascomycete Mycosphaerella graminicola is the causal agent of septoria tritici blotch (STB), one of the most destructive foliar diseases of bread and durum wheat globally, particularly in temperate humid areas. A screening of the French bread wheat cultivars Apache and Balance with 30 M. graminicola isolates revealed a pattern of resistant responses that suggested the presence of new genes for STB resistance. Quantitative trait loci (QTL) analysis of a doubled haploid (DH) population with five M. graminicola isolates in the seedling stage identified four QTLs on chromosomes 3AS, 1BS, 6DS and 7DS, and occasionally on 7DL. The QTL on chromosome 6DS flanked by SSR markers Xgpw5176 and Xgpw3087 is a novel QTL that now can be designated as Stb18. The QTLs on chromosomes 3AS and 1BS most likely represent Stb6 and Stb11, respectively, and the QTLs on chromosome 7DS are most probably identical with Stb4 and Stb5. However, the QTL identified on chromosome 7DL is expected to be a new Stb gene that still needs further characterization. Multiple isolates were used and show that not all isolates identify all QTLs, which clearly demonstrates the specificity in the M. graminicola-wheat pathosystem. QTL analyses were performed with various disease parameters. The development of asexual fructifications (pycnidia) in the characteristic necrotic blotches of STB, designated as parameter P, identified the maximum number of QTLs. All other parameters identified fewer but not different QTLs. The segregation of multiple QTLs in the Apache/Balance DH population enabled the identification of DH lines with single QTLs and multiple QTL combinations. Analyses of the marker data of these DH lines clearly demonstrated the positive effect of pyramiding QTLs to broaden resistance spectra as well as epistatic and additive interactions between these QTLs. Phenotyping of the Apache/Balance DH population in the field confirmed the presence of the QTLs that were identified in the seedling stage, but Stb18 was inconsistently expressed and might be particularly effective in young plants. In contrast, an additional QTL for STB resistance was identified on chromosome 2DS that is exclusively and consistently expressed in mature plants over locations and time, but it was also strongly related with earliness, tallness as well as resistance to Fusarium head blight. Although to date no Stb gene has been reported on chromosome 2D, the data provide evidence that this QTL is only indirectly related to STB resistance. This study shows that detailed genetic analysis of contemporary commercial bread wheat cultivars can unveil novel Stb genes that can be readily applied in marker-assisted breeding programs