High-resolution mapping of the barley Ryd3 locus controlling tolerance to BYDV
Lüpken, T. ; Stein, N. ; Perovic, D. ; Habekuss, A. ; Serfling, A. ; Krämer, I. ; Hähnel, U. ; Steuernagel, B. ; Scholz, U. ; Ariyadasa, R. ; Martis, M. ; Mayer, K. ; Niks, R.E. ; Collins, N.C. ; Friedt, W. ; Ordon, F. - \ 2014
Molecular Breeding 33 (2014)2. - ISSN 1380-3743 - p. 477 - 488.
yellow-dwarf-virus - hordeum-vulgare l. - recessive bymovirus resistance - leaf rust resistance - comparative genomics - consensus map - winter barley - linkage map - yd2 gene - sequence
Barley yellow dwarf disease (BYD) is transmitted by aphids and is caused by different strains of Barley yellow dwarf virus (BYDV) and Cereal yellow dwarf virus (CYDV). Economically it is one of the most important diseases of cereals worldwide. Besides chemical control of the vector, growing of tolerant/resistant cultivars is an effective way of protecting crops against BYD. The Ryd3 gene in barley (Hordeum vulgare L.) confers tolerance to BYDV-PAV and BYDV-MAV and the locus was previously mapped on the short arm of barley chromosome 6H near the centromere. We applied a strategy for high-resolution mapping and marker saturation at the Ryd3 locus by exploiting recent genomic tools available in barley. In a population of 3,210 F2 plants, 14 tightly linked markers were identified, including 10 that co-segregated with Ryd3. The centromeric region where Ryd3 is located suffers suppressed recombination or reduced recombination rate, suggesting potential problems in achieving (1) map-based cloning of Ryd3 and (2) marker selection of the resistance in breeding programmes without the introduction of undesirable traits via linkage drag.
System-Wide Hypersensitive Response-Associated Transcriptome and Metabolome Reprogramming in Tomato
Etalo, D.W. ; Stulemeijer, I.J.E. ; Esse, H.P. van; Vos, R.C.H. de; Bouwmeester, H.J. ; Joosten, M.H.A.J. - \ 2013
Plant Physiology 162 (2013)3. - ISSN 0032-0889 - p. 1599 - 1617.
programmed cell-death - pathogen pseudomonas-syringae - campestris pv. vesicatoria - glutathione s-transferases - amino-acid catabolism - leaf rust resistance - higher-plant cells - mass-spectrometry - cladosporium-fulvum - functional-analysis
The hypersensitive response (HR) is considered to be the hallmark of the resistance response of plants to pathogens. To study HR-associated transcriptome and metabolome reprogramming in tomato (Solanum lycopersicum), we used plants that express both a resistance gene to Cladosporium fulvum and the matching avirulence gene of this pathogen. In these plants, massive reprogramming occurred, and we found that the HR and associated processes are highly energy demanding. Ubiquitin-dependent protein degradation, hydrolysis of sugars, and lipid catabolism are used as alternative sources of amino acids, energy, and carbon skeletons, respectively. We observed strong accumulation of secondary metabolites, such as hydroxycinnamic acid amides. Coregulated expression of WRKY transcription factors and genes known to be involved in the HR, in addition to a strong enrichment of the W-box WRKY-binding motif in the promoter sequences of the coregulated genes, point to WRKYs as the most prominent orchestrators of the HR. Our study has revealed several novel HR-related genes, and reverse genetics tools will allow us to understand the role of each individual component in the HR.
The need to breed crop varieties suitable for organic farming, using wheat, tomato and broccoli as examples: A review
Lammerts Van Bueren, E. ; Jones, S.S. ; Tamm, L. ; Murphy, K.M. ; Myers, J.R. ; Leifert, C. ; Messmer, M.M. - \ 2011
NJAS Wageningen Journal of Life Sciences 58 (2011)3-4. - ISSN 1573-5214 - p. 193 - 205.
triticum-aestivum l. - quantitative trait loci - nitrogen use efficiency - arbuscular mycorrhizal fungi - fusarium head blight - leaf rust resistance - genetic-linkage map - near-isogenic lines - low-input systems - red spring wheat
It is estimated that more than 95% of organic production is based on crop varieties that were bred for the conventional high-input sector. Recent studies have shown that such varieties lack important traits required under organic and low-input production conditions. This is primarily due to selection in conventional breeding programmes being carried out in the background of high inorganic fertilizer and crop protection inputs. Also, some of the traits (e.g., semi-dwarf genes) that were introduced to address problems like lodging in cereals in high-input systems were shown to have negative side-effects (reduced resistance to diseases such as Septoria, lower protein content and poorer nutrient-use efficiency) on the performance of varieties under organic and low-input agronomic conditions. This review paper, using wheat, tomato and broccoli as examples, describes (1) the main traits required under low-input conditions, (2) current breeding programmes for organic, low-input agriculture, (3) currently available breeding and/or selection approaches, and (4) the benefits and potential negative side-effects of different breeding methodologies and their relative acceptability under organic farming principles
Isolate specificity of quantitative trait loci for partial resistance of barley to Puccinia hordei confirmed in mapping populations and near-isogenic lines
Marcel, T.C. ; Gorguet, B.J.M. ; Truong Ta, M. ; Kohutova, Z. ; Vels, S.A. ; Niks, R.E. - \ 2008
New Phytologist 177 (2008)3. - ISSN 0028-646X - p. 743 - 755.
leaf rust resistance - polygenic resistance - disease resistance - gene rph7 - qtls - identification - fungal - plants - cultivars - pathogens
¿ Partial resistance is considered race-nonspecific and durable, consistent with the concept of `horizontal¿ resistance. However, detailed observations of partial resistance to leaf rust (Puccinia hordei) in barley (Hordeum vulgare) revealed small cultivar × isolate interactions, suggesting a minor-gene-for-minor-gene interaction model, similar to so-called `vertical¿ resistance. ¿ Three consistent quantitative trait loci (QTLs), labelled Rphq2, Rphq3 and Rphq4, that were detected in the cross susceptible L94 × partially resistant Vada have been incorporated into the L94 background to obtain near-isogenic lines (NILs). Three isolates were used to map QTLs on seedlings of the L94 × Vada population and to evaluate the effect of each QTL on adult plants of the respective NILs under field conditions. ¿ Rphq2 had a strong effect in seedlings but almost no effect in adult plants, while Rphq3 was effective in seedlings and in adult plants against all three isolates. However, Rphq4 was effective in seedlings and in adult plants against two isolates but ineffective in both development stages against the third, demonstrating a clear and reproducible isolate-specific effect. The resistance governed by the three QTLs was not associated with a hypersensitive reaction. ¿ Those results confirm the minor-gene-for-minor-gene model suggesting specific interactions between QTLs for partial resistance and P. hordei isolates.