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Laurence Hibrand-Saint Oyant

Bio: Laurence Hibrand-Saint Oyant is an academic researcher from University of Angers. The author has contributed to research in topics: Population & Quantitative trait locus. The author has an hindex of 5, co-authored 9 publications receiving 196 citations. Previous affiliations of Laurence Hibrand-Saint Oyant include Agrocampus Ouest & Institut national de la recherche agronomique.

Papers
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Journal ArticleDOI
03 Jul 2015-Science
TL;DR: Combining transcriptomic and genetic approaches, it is shown that the Nudix hydrolase RhNUDX1, localized in the cytoplasm, is part of a pathway for the biosynthesis of free monoterpene alcohols that contribute to fragrance in roses.
Abstract: The scent of roses (Rosa x hybrida) is composed of hundreds of volatile molecules. Monoterpenes represent up to 70% percent of the scent content in some cultivars, such as the Papa Meilland rose. Monoterpene biosynthesis in plants relies on plastid-localized terpene synthases. Combining transcriptomic and genetic approaches, we show that the Nudix hydrolase RhNUDX1, localized in the cytoplasm, is part of a pathway for the biosynthesis of free monoterpene alcohols that contribute to fragrance in roses. The RhNUDX1 protein shows geranyl diphosphate diphosphohydrolase activity in vitro and supports geraniol biosynthesis in planta.

154 citations

Journal ArticleDOI
TL;DR: It is concluded that RoKSN is a floral repressor and is also involved in the vegetative development of rose, which forms a complex with RoFD and could compete with RoFT for repression of flowering.
Abstract: FT/TFL1 family members have been known to be involved in the development and flowering in plants. In rose, RoKSN, a TFL1 homologue, is a key regulator of flowering, whose absence causes continuous flowering. Our objectives are to functionally validate RoKSN and to explore its mode of action in rose. We complemented Arabidopsis tfl1 mutants and ectopically expressed RoKSN in a continuous-flowering (CF) rose. Using different protein interaction techniques, we studied RoKSN interactions with RoFD and RoFT and possible competition. In Arabidopsis, RoKSN complemented the tfl1 mutant by rescuing late flowering and indeterminate growth. In CF roses, the ectopic expression of RoKSN led to the absence of flowering. Different branching patterns were observed and some transgenic plants had an increased number of leaflets per leaf. In these transgenic roses, floral activator transcripts decreased. Furthermore, RoKSN was able to interact both with RoFD and the floral activator, RoFT. Protein interaction experiments revealed that RoKSN and RoFT could compete with RoFD for repression and activation of blooming, respectively. We conclude that RoKSN is a floral repressor and is also involved in the vegetative development of rose. RoKSN forms a complex with RoFD and could compete with RoFT for repression of flowering.

68 citations

Journal ArticleDOI
TL;DR: High heritability estimates obtained for garden rose architecture indicated that architectural characteristics are feasible targets of rose breeding and candidate genes involved in gibberellin biosynthesis and auxin signalling can be good targets for future physiological studies.
Abstract: Understanding the genetic basis of plant architecture is limited for woody plants due to the challenges of assessing the inheritance of their complex architecture. We aimed to evaluate the genetic variability of plant form and stature in a garden rose population, analyse the inheritance of plant architecture and its linkage with flowering behaviour and identify the quantitative trait loci (QTLs) controlling garden rose architecture. A total of 98 F 1 hybrids were derived from the cross between two diploid roses, The Fairy (TF) and Rosa × wichurana (RW) that differed in stature and flowering behaviour. The TF exhibits continuous flowering (CF) and has erect stature. The RW is once flowering (OF) and prostrate in stature. Three clones per genotype were multiplied, and a total of 300 plants were cultivated in a field. Flowering behaviour, plant form, plant height, stem diameter and internode length were scored during each of 2 years. All architectural traits had significant genetic variances (29–61 % of their respective phenotypic variances), and their broad-sense heritability estimates were 0.76–0.92. The majority of CF progeny was erect, whereas the OF progeny was prostrate, suggesting a linkage between plant form and flowering behaviour. The QTL analysis identified eight major QTLs controlling architectural traits. Several candidate genes involved in gibberellin biosynthesis and auxin signalling were identified in the vicinity of the QTLs. High heritability estimates obtained for garden rose architecture indicated that architectural characteristics are feasible targets of rose breeding. Linkage of plant form and flowering behaviour, however, prevents independent selection of these traits. The candidate genes identified can be good targets for future physiological studies.

17 citations

Journal ArticleDOI
TL;DR: Year-specific QTLs were revealed, that explained the genotype × year interactions observed for the number of order 3 short axes (NbSA3) and AngLA2 from a genetic point of view and an effect of the genetic background on QTL detection.
Abstract: Plant shape, and thereby plant architecture, is a major component of the visual quality of ornamental plants We have been developing a new method for analyzing the entire plant architecture by 3D digitalization that allows an almost exhaustive description of rose bush architecture and generates a large number of variables, many of them inaccessible manually We carried out a QTL analysis using this original phenotyping method In order to evaluate a broader allelic variability as well as the effect of the genetic background on QTL detection, we used two connected, segregating, recurrent blooming populations The number of QTLs per variable varied from three for the number of determined axes (NbDetA) to seven for the branching angle of order 2 long axes (AngLA2), the two populations taken together Five new QTLs, located on the linkage groups (LGs) 2, 6, and 7, were detected for the branching angle of axes, and the QTL located on LG7 co-localized with RhBRC1, a branching repressor Branching and stem elongation QTLs also co-located with RhBRC1, suggesting its pleiotropic nature Year-specific QTLs were also revealed, that explained the genotype × year interactions observed for the number of order 3 short axes (NbSA3) and AngLA2 from a genetic point of view We also evidenced an effect of the genetic background on QTL detection This new knowledge should help to better reason the genetic improvement programs for rose bush architecture and, therefore, rose bush shape

14 citations

Journal ArticleDOI
TL;DR: The main tools developed in this paper could be use to tackle the general problem of QTL mapping of complex (sequences, 3D structure, graphs) phenotypic traits.

10 citations


Cited by
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28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
TL;DR: The rose whole-genome sequencing and assembly and resequencing of major genotypes that contributed to rose domestication and a model of interconnected regulation of scent and flower color are proposed, providing a foundation for understanding the mechanisms governing rose traits.
Abstract: Roses have high cultural and economic importance as ornamental plants and in the perfume industry. We report the rose whole-genome sequencing and assembly and resequencing of major genotypes that contributed to rose domestication. We generated a homozygous genotype from a heterozygous diploid modern rose progenitor, Rosa chinensis ‘Old Blush’. Using single-molecule real-time sequencing and a meta-assembly approach, we obtained one of the most comprehensive plant genomes to date. Diversity analyses highlighted the mosaic origin of ‘La France’, one of the first hybrids combining the growth vigor of European species and the recurrent blooming of Chinese species. Genomic segments of Chinese ancestry identified new candidate genes for recurrent blooming. Reconstructing regulatory and secondary metabolism pathways allowed us to propose a model of interconnected regulation of scent and flower color. This genome provides a foundation for understanding the mechanisms governing rose traits and should accelerate improvement in roses, Rosaceae and ornamentals.

292 citations

Journal ArticleDOI
TL;DR: The comprehensively survey the conserved and diverse functions of the FT/TFL1 gene family throughout the plant kingdom, summarize new findings regarding the unique evolution of FT in multiple species, and highlight recent work elucidating the molecular mechanisms of these proteins.

268 citations

Journal Article
30 Oct 1994-Genomics
TL;DR: In this paper, an empirical method based on the concept of permutation test is proposed for estimating threshold values that are tailored to the experimental data at hand, which is demonstrated using two real data sets derived from F(2) and recombinant inbred plant populations.

255 citations

Journal ArticleDOI
TL;DR: This work proposes several pathways involving not only the classical hormones auxin, cytokinins and strigolactones, but also other signals with a strong influence on shoot branching such as gibberellins, sugars or molecular actors of plant phase transition.
Abstract: Shoot branching patterns result from the spatio-temporal regulation of axillary bud outgrowth. Numerous endogenous, developmental and environmental factors are integrated at the bud and plant levels to determine numbers of growing shoots. Multiple pathways that converge to common integrators are most probably involved. We propose several pathways involving not only the classical hormones auxin, cytokinins and strigolactones, but also other signals with a strong influence on shoot branching such as gibberellins, sugars or molecular actors of plant phase transition. We also deal with recent findings about the molecular mechanisms and the pathway involved in the response to shade as an example of an environmental signal controlling branching. We propose the TEOSINTE BRANCHED1, CYCLOIDEA, PCF transcription factor TB1/BRC1 and the polar auxin transport stream in the stem as possible integrators of these pathways. We finally discuss how modeling can help to represent this highly dynamic system by articulating knowledges and hypothesis and calculating the phenotype properties they imply.

253 citations