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Hugueney, P.

Publications and source records attributed to Hugueney, P..

8 recordsLinked to original sources

Genetic analysis of grapevine wood composition identifies glycosyltransferases involved in the biosynthesis of stilbene glycosides

Although wood extractives may play important roles in defense against pathogens, few studies have explored the genetic determinism of their accumulation. In this work, we have used a non-targeted metabolomic approach to perform a genetic analysis of grapevine (Vitis vinifera) wood extractive composition in a progeny from a cross between Riesling and Gewurztraminer. Metabolic quantitative trait loci (mQTL) analyses of cane and trunk wood extractives revealed a number of mQTLs. Analysis of one of these mQTL has led to the identification of a cluster of six UDP glycosyltransferase (UGT) genes linked to the accumulation of resveratrol-glucoside (piceid) in both canes and trunks. Detailed biochemical and structural characterization of these six UGTs highlighted a surprising functional diversity among this small gene family, as well as one UGT gene as a key determinant of the constitutive accumulation of piceid in lignified grapevine tissues. Molecular evolution analyses showed that the UGTs in this gene cluster were globally under strong purifying selection, suggesting important biological roles of the corresponding proteins. Moreover, the functional characterization showed that distinct UGT genes were involved in the biosynthesis of cis- and trans- isomers of piceid, suggesting that these isomers may play different biological roles in grapevine.

plant biology↗

Comparative assessment of genomic, phenomic, and metabolomic prediction models in biparental grapevine breeding populations

Accelerating grapevine breeding for disease resistance and climate adaptation remains constrained by long generation cycles. We benchmarked genomic (SNP), phenomic (NIRS), and metabolomic (untargeted LC-MS) prediction for 24 agronomic traits in a biparental population phenotyped over three years. Seven statistical frameworks and four tissue x timepoint combinations (wood; vineyard leaves at budbreak and flowering; greenhouse leaves at flowering) were evaluated, together with feature-wise BLUPs across samples. Cross-year and cross-population analyses with two additional populations assessed temporal robustness and transferability. Genomic prediction was most accurate (up to r = 0.83), metabolomic prediction was intermediate (up to r = 0.59), and phenomic prediction was lowest (up to r = 0.39) despite its lower acquisition cost. Metabolite features were more heritable than NIR wavelengths, for which most unexplained variation remained residual under the fitted model. Multi-omics integration produced limited overall gains. These results support genomic selection as the primary approach, with metabolomic or phenomic screening considered only for traits and sampling designs that show reproducible predictive signal.

genomics↗

Metabolic biomarker-based phenotyping unveils quantitative effects of plant resistance and pathogen aggressiveness in the grapevine (Vitis spp.) - downy mildew (Plasmopara viticola) pathosystem.

Grapevine resistance to downy mildew has been primarily associated with major "Resistance to Plasmopara viticola" (Rpv) loci, which are extensively used in breeding programs. Resistant varieties represent an effective solution to mitigate the environmental impact of fungicide application in viticulture, but P. viticola strains able to overcome major Rpv have become a main threat to their cultivation. Pyramiding resistance loci in the same variety enhances plant resistance, but interactions involving stacked and defeated Rpv and different P. viticola strains are poorly documented. Investigation of these interactions may uncover new information for the development of efficient breeding strategies, the optimal exploitation of Rpv, and the building of durable resistance. In the present study, a grapevine offspring carrying single and pyramided Rpv1, Rpv3.1 and Rpv10 was phenotyped in laboratory conditions for the resistance to P. viticola using a naive strain and a strain virulent towards Rpv10. By using a high-resolution phenotyping strategy based on P. viticola metabolic biomarkers, we demonstrated that the efficacy of Rpv combinations and aggressiveness of P. viticola strains can be quantified in the early phase of infection and were often related to sporulation outcome. Furthermore, we described how a limited residual effect of a defeated Rpv may become significant in pyramiding. In conclusion, in addition to providing the keys to streamlining resistance utilization in grapevine, our research presents a distinctive case study that provides valuables information for breeding new resistant varieties, thanks to an innovative "omic"-based phenotyping approach, which may be adapted to other plant pathosystems.

plant biology↗

Breeding for durable resistance in crops: defeated loci may act as Trojan horses compromising the effectiveness of major resistance genes.

Resistance breeding offers invaluable perspectives for environment-friendly crop protection, but its success may be limited by the breakdown of plant resistance by pathogen strains. This threat is particularly acute for perennial crops, which may be cultivated for several decades. With the increasing use of new varieties carrying multiple major resistance loci, grapevine (Vitis spp.) represents a distinctive model to investigate the broad agreement that combining several resistance genes (pyramiding) enhances both resistance efficacy and durability. To this end, grapevine progenies segregating for four resistance loci against Plasmopara viticola (Rpvs) were used to evaluate the efficiency of single and pyramided major loci when confronted to naive and Rpv-breaking pathogen strains. In the context of polygenic resistance, both undefeated and defeated Rpvs provided significant quantitative effects. However, interactions between pyramided Rpvs were either beneficial, neutral or detrimental to the level of resistance, depending on the loci combination and pathogen strain. In particular, the fact that the presence of defeated resistance loci may compromise the resistance provided by functional major loci has important implications for crops resistance breeding. Thorough phenotypic investigations of pyramiding breeding schemes emerge as a critical step for the effective and durable management of genetic resistances and plant diseases.

plant biology↗

The single-berry metabolomic clock paradigm reveals new stages and metabolic switches during grapevine berry development

O_LIAsynchronous development of berries causes metabolic chimerism in usual samples. We thus revisited the developmental changes in the metabolome of the Vitis vinifera single berries from anthesis to over-ripening. C_LIO_LIA dataset of 9,256 ions obtained by non-targeted ultra-performance liquid chromatography coupled to high-resolution mass spectrometry was submitted to an analysis workflow combining classification and dimension reduction tools, to reveal the dynamics of metabolite composition without phenological a priori. C_LIO_LIThis approach led to a metabolome-based definition of developmental stages, as well as the clustering of metabolites into 12 specific kinetic patterns. The single berry intrinsic metabolomic clock alleviates constitutive asynchronicity biases in the usual combination of phenological scales and observer clock. Such increase in temporal resolution enabled the identification of metabolite clusters annunciative of the onset of ripening since the herbaceous plateau. In particular, these clusters included transient lipidic changes and the start of ABA accumulation. We also highlighted a cluster of stilbenes that accumulate after sugar loading stops, during fruit shriveling. C_LIO_LIThis non-targeted approach enables a more precise and unbiased characterization of grapevine berry development through the metabolomic clock paradigm. The discovery of new metabolic milestones of berry development paves the way towards an unbiased assessment of berry physiological stages. C_LI

plant biology↗

An improved reference of the grapevine genome supports reasserting the origin of the PN40024 highly-homozygous genotype

The genome sequence assembly of the diploid and highly homozygous V. vinifera genotype PN40024 serves as the reference for many grapevine studies. Despite several improvements of the PN40024 genome assembly, its current version PN12X.v2 is quite fragmented and only represents the haploid state of the genome with mixed haplotypes. In fact, despite the PN40024 genome is nearly homozygous, it still contains various heterozygous regions. Taking the opportunity of the improvements that long-read sequencing technologies offer to fully discriminate haplotype sequences and considering that several Vitis sp. genomes have recently been assembled with these approaches, an improved version of the reference, called PN40024.v4, was generated. Through incorporating long genomic sequencing reads to the assembly, the continuity of the 12X.v2 scaffolds was highly increased. The number of scaffolds decreased from 2,059 to 640 and the number of N bases was reduced by 88%. Additionally, the full alternative haplotype sequence was built for the first time, the chromosome anchoring was improved and the amount of unplaced scaffolds were reduced by half. To obtain a high-quality gene annotation that outperforms previous versions, a liftover approach was complemented with an optimized annotation workflow for Vitis. Integration of the gene reference catalogue and its manual curation have also assisted in improving the annotation, while defining the most reliable estimation to date of 35,230 genes. Finally, we demonstrate that PN40024 resulted from selfings of cv. Helfensteiner (cross of cv. Pinot noir and Schiava grossa) instead of a single Pinot noir. These advances will help maintaining the PN40024 genome as a gold-standard reference also contributing in the eventual elaboration of the grapevine pangenome.

genomics↗

Metabolic consequences of various fruit-based diets in a generalist insect species

Most phytophagous insect species exhibit a limited diet breadth and specialize on few or a single host plant. In contrast, some species display a remarkably large diet breadth, with host plants spanning several families and many species. It is unclear, however, whether this phylogenetic generalism is supported by a generic metabolic use of common host chemical compounds ( metabolic generalism) or alternatively by distinct uses of diet-specific compounds ( multi-host metabolic specialism)? Here, we simultaneously investigated the metabolomes of fruit diets and of individuals of a generalist phytophagous species, Drosophila suzukii, that developed on them. The direct comparison of metabolomes of diets and consumers enabled us to disentangle the metabolic fate of common and rarer dietary compounds. We showed that the consumption of biochemically dissimilar diets resulted in a canalized, generic response from generalist individuals, consistent with the metabolic generalism hypothesis. We also showed that many diet-specific metabolites, such as related to the particular color, odor or taste of diets, were not metabolized, and rather accumulated in consumer individuals, even when probably detrimental to fitness. As a result, while individuals were mostly similar across diets, the detection of their particular diet was straightforward. Our study thus supports the view that dietary generalism may emerge from a passive, opportunistic use of various resources, contrary to more widespread views of an active role of adaptation in this process. Such a passive stance towards dietary chemicals, probably costly in the short term, might favor the later evolution of new diet specializations.

ecology↗

The wild grape genome sequence provides insights into the transition from dioecy to hermaphroditism during grape domestication

Grapevine has a major economical and cultural importance since antiquity. A key step in domestication was the transition from separate sexes (dioecy) in wild Vitis vinifera ssp. sylvestris (V. sylvestris) to hermaphroditism in cultivated Vitis vinifera ssp. vinifera. While the grapevine sex locus is known to be small, its precise boundaries, gene content and the sex-determining genes are unknown. Here we obtained a high-quality de novo reference genome for V. sylvestris and whole-genome resequencing data of a cross. Studying SNP segregation patterns, gene content and expression in wild and cultivated accessions allowed us to build a model for sex determination in grapevine. In this model, up- and down-regulation of a cytokinin regulator is sufficient to cause female sterility and reversal to hermaphroditism, respectively. This study highlights the importance of neo-functionalization of Y alleles in sex determination and provides a resource for studying genetic diversity in V. sylvestris and the genomic processes of grapevine domestication.

plant biology↗