References of "Périlleux, Claire"
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See detailSearching for interactions at the membrane interface that confer antagonistic activities on floral regulators FT and TFL1
Pottier, Mathieu ULiege; Orman-Ligeza, Beata; Redouté, Gaëlle et al

Poster (2019, July)

In plants, the switch from leaf- to flower-producing meristems is controlled by the FLOWERING LOCUS T (FT) and TERMINAL FLOWER 1 (TFL1) proteins. FT is a major component of the so-called "florigen", a ... [more ▼]

In plants, the switch from leaf- to flower-producing meristems is controlled by the FLOWERING LOCUS T (FT) and TERMINAL FLOWER 1 (TFL1) proteins. FT is a major component of the so-called "florigen", a systemic signal that moves from leaves to shoot meristems and triggers the floral transition. By contrast, TFL1 is expressed in the shoot meristems and represses flowering, antagonising FT. Despite their opposite functions, FT and TFL1 are both members of the same family, showing homology to PHOSPHATIDYLETHANOLAMINE BINDING PROTEINs (PEBPs). They are unable to bind phosphatidylethanolamines though, but bind phosphatidylcholines that are major phospholipids of plant membranes and whose concentration impacts flowering time (Nakamura et al., 2014). The mechanisms by which FT and TFL1 regulate floral transition have been focused on their ability to complex with the transcription factor FD, which itself regulates floral identity genes. However, the loss of FD function does not abolish flowering and hence other interactors remain to be identified. We are therefore investigating in further detail the ability of Arabidopsis FT and TFL1 proteins to interact with membrane lipids and proteins. Langmuir method and molecular dynamics are currently being undertaken to characterize FT and TFL1 interactions with different phospholipids and to simulate their behaviors in contact with membranes, respectively. In parallel, FT and TFL1 protein interactomes are being investigated. We are performing in vitro pulldown assays using His-FT and His-TFL1 as baits and solubilized membranes proteins from cauliflower meristem as preys, taking advantage of the conservation of flowering genes among Brassicaceae. In parallel, complementation of Arabidopsis ft and tfl1 mutants with FT-GS and TFL1-GS constructs allowed us to perform in vivo co-purification analyses. This work will provide us with a better understanding of FT and TFL1 actions and highlight missing checkpoints of the floral transition. [less ▲]

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See detailPeut-on inventer de nouvelles plantes ?
Périlleux, Claire ULiege; Dommes, Jacques ULiege

Conference given outside the academic context (2019)

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See detailArchitectural and developmental changes due to overexpression of the JOINTLESS gene in tomato
Huerga Fernandez, Samuel ULiege; Orman-Ligeza, Beata; Périlleux, Claire ULiege

Poster (2019, June)

Inflorescence architecture shows huge variation among flowering plants, especially in the amount of flowers and branching degree. In tomato, the formation of the inflorescence follows a sympodial pattern ... [more ▼]

Inflorescence architecture shows huge variation among flowering plants, especially in the amount of flowers and branching degree. In tomato, the formation of the inflorescence follows a sympodial pattern : the shoot apical meristem (SAM) acquires a floral meristem (FM) fate and forms the first flower while a lateral inflorescence meristem (IM) is initiated, which itself matures into a FM when a second IM is initiated, and so on. This sympodial mode of inflorescence development is regulated by a complex genetic network, which remains to be elucidated. Tomato is also used as a model in the study of abscission, an important process by which plants can isolate and drop different parts such as non fertilized flowers, damaged organs or ripe fruits. The lack of fruit abscission zone – the “jointless” phenotype – is associated with the j and j-2 mutations, which impair the function of two MADS-box genes: JOINTLESS (J) and SlMBP21. We are interested in understanding the functions of J, because j knock-out mutation does not only alter the abscission zone but causes inflorescence reversion to leaf production after the initiation of few flowers. Our goal is therefore to identify the targets of J by different molecular approaches. [less ▲]

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See detailThe PEBP family of genes in chicory and their role in flowering time and root development
Roumeliotis, Efstathios ULiege; Saintmard, Nicolas; Dauchot, Nicolas et al

Poster (2019, April 25)

The PHOSPHATIDYLETHANOLAMINE-BINDING PROTEIN (PEBP) gene family is present in all eukaryotic kingdoms. In plants, three separate subfamilies have been identified, all of which have diversified functions ... [more ▼]

The PHOSPHATIDYLETHANOLAMINE-BINDING PROTEIN (PEBP) gene family is present in all eukaryotic kingdoms. In plants, three separate subfamilies have been identified, all of which have diversified functions. In Arabidopsis thaliana, the PEBP family members have been assigned roles as promoting or repressing flowering, controlling inflorescence meristem determinacy and axillary bud growth. Members of the PEBP family have also been identified to play a role in tuber initiation in potato but not much is known about the role of PEBPs in root development, especially for species that form storage roots. Root chicory (Cichorium intybus var. sativum) is a biennial crop used for nutrition, animal feed and as coffee substitute and is one of the most important sources of inulin, a type of polysaccharides that is gaining great importance in the food and medical industry. Chicory root extracts have been found to have hepatoprotective, anti-bacterial, anti- inflammatory, anti-microbial, nematicidal and anti-cancer effects. With the use of bioinformatic tools, the sequences of chicory FLOWERING LOCUS T (CiFT) and TERMINAL FLOWER1 (CiTFL1-1 to 4) like genes were identified and the coding sequences were overexpressed in null A. thaliana mutants (ft-10 or tfl1). Independent transgenic lines for each gene were phenotyped for flowering time and root development. In addition, the expression pattern of these genes was analyzed in chicory in various tissues during early stages of plant development and initiation of root storage. Transformation of chicory is being performed using an Agrobacterium rhizogenes in vitro transformation protocol. The results of this project will help us elucidate the role for the PEBPs in flowering and root development in chicory. [less ▲]

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See detailTurning meristems into fortresses
Périlleux, Claire ULiege; Bouché, Frédéric ULiege; Randoux, Marie et al

in Trends in Plant Science (2019), 24(5), 431-442

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See detailThe xerobranching response represses lateral root formation when roots are not in contact with water.
Orman-Ligeza, Beata; Morris, Emily C.; Parizot, Boris et al

in Current Biology (2018), 28

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See detailRooting the flowering process
Périlleux, Claire ULiege

Scientific conference (2018, September 28)

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See detailRooting the flowering process
Périlleux, Claire ULiege

Conference (2018, September 21)

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See detailOverexpression of the tomato JOINTLESS gene alters flowering
Huerga Fernandez, Samuel ULiege; Orman-Ligeza, Beata; Goossens, Chiara ULiege et al

Poster (2018, May 17)

Abscission is an important mechanism that allows plants to separate unfertilized flowers, ripe fruits or damage organs from the plant. In tomato, jointless (j) and jointless-2 (j-2) mutations leads a lack ... [more ▼]

Abscission is an important mechanism that allows plants to separate unfertilized flowers, ripe fruits or damage organs from the plant. In tomato, jointless (j) and jointless-2 (j-2) mutations leads a lack of abscission zone (AZ) in the flower pedicel, which will avoid falling of ripe fruits and prevent loss of yield. Both J and J-2 are genes encoding MADS-box transcription factors (Mao et al. 2000; Gomez-Roldan et al., 2017) that can interact with other MADS-box proteins, like MACROCALYX (MC), forming a multimeric complex able to regulate the AZ formation (Liu et al. 2014). In addition to the AZ formation, J also plays a role in flowering architecture and meristem fate. This last role is consistent with the functions of the closets homologs of J in Arabidopsis, SHORT VEGETATIVE PHASE (SVP) and AGAMOUS LIKE 24 (AGL24) (Gregis et al. 2006). Mutation of J leads to a faster flower maturation and a reversion to the vegetative state of the inflorescence meristems, which originates leafy inflorescences (Périlleux et al. 2014). Nevertheless, J is not the only one that regulates at the same time AZ formation and meristem functions. Other transcription factors such as the tomato homolog of WUSHEL (LeWUS), GOBLET (GOB), LATERAL SUPPRESSOR (Ls) and Blind (Bl) are involved in those pathways (Nakano et al. 2012; Nakano et al. 2013). We have generated transgenic plants that overexpress J (35S:J) showing changes in the inflorescence architecture and AZ development, but also having interesting phenotypes in axillary development and leaf complexity. These results suggest that J takes part in different pathways and regulate several downstream genes. Our goal is to identify and study the targets of the J transcription factor in order to understand its functions in the tomato plant. [less ▲]

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See detailRooting the Flowering Process (Part I) and Inflorescence Development in Tomato (Part II)
Périlleux, Claire ULiege

Scientific conference (2018, February 09)

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See detailLes mystères de la floraison
Périlleux, Claire ULiege

Conference given outside the academic context (2017)

Detailed reference viewed: 17 (3 ULiège)
See detailFlowering roots: Insensitive Root Growth 1 contributes to photoperiod-induced root responses in Arabidopsis.
Orman-Ligeza, Beata ULiege; Detry, Nathalie ULiege; Tocquin, Pierre ULiege et al

Poster (2017, September)

The capacity to perceive and respond to seasonal changes of day length is essential for flowering plants. Under favourable photoperiod, a mobile stimulus synthesized in leaves moves to the shoot apex and ... [more ▼]

The capacity to perceive and respond to seasonal changes of day length is essential for flowering plants. Under favourable photoperiod, a mobile stimulus synthesized in leaves moves to the shoot apex and triggers the expression of genes required for the transition to flower initiation. Although transition from vegetative to reproductive state also encompasses a transcriptional response in roots, the internal signalling pathways and how root system architecture adjusts to this changing status remain elusive. Here we show in Arabidopsis that root growth rate increases upon a transfer to flowering-inductive long days while remaining constant under short days. To elucidate genetic components of this response, we performed a meta-analysis of available root-growth and flowering-related arrays and selected genes with overlapping transcriptional profiles for further analyses. Loss of function in a member of the basic leucine zipper transcription factor gene family, hereafter named Insensitive Root Growth-1 (IRG1), was found to suppress photoperiod-response of root growth with no defect in flowering time. We show that sucrose, but neither glucose nor mannitol in the growth medium under long days, is needed to trigger this response. In addition, extending the photoperiod with non-photosynthetic far red light had no effect on root growth of irg-1 mutant, alike wild type Col-0. The expression level of IRG1 in the roots remains low during the daytime and peaks late at night, suggesting that this gene is regulated by the clock’s evening loop. Taken together, our results suggest that IRG1 may be involved in sucrose-mediated stimulation of root growth during the night phase in Arabidopsis. The functional characterisation of IRG1 is currently underway. [less ▲]

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See detailTowards understanding the function of JOINTLESS gene in tomato inflorescence
Huerga Fernandez, Samuel ULiege; Gómez Roldán, Maria Victoria; Orman-Ligeza, Beata ULiege et al

Poster (2017, September)

The lack of fruit abscission is a trait of great agronomical value. In tomato, the jointless phenotype, referring to the lack of abscission zone (AZ) in the flower pedicel, has been obtained by two ... [more ▼]

The lack of fruit abscission is a trait of great agronomical value. In tomato, the jointless phenotype, referring to the lack of abscission zone (AZ) in the flower pedicel, has been obtained by two independent mutations, named jointless (j) and jointless-2 (j-2). The corresponding genes encode MADS-box transcription factors, as shown in 2000 for J (Mao et al. 2000) and very recently for J-2, known as SlMBP21 (Gomez-Roldan et al., 2017). Similar to the quartet model of MADS-box protein complexes regulating floral organ formation, J and J-2 interact with MADS-box partners, among which MACROCRALYX (MC), to regulate AZ formation (Liu et al. 2014). In addition to - or in connection with - AZ formation, J acts during the building of the inflorescence to regulate meristem fate. Indeed j mutants produce leafy inflorescences characterized by faster flower maturation and resumption of vegetative meristems (Périlleux et al. 2014). For these traits, j is epistatic to j-2. The involvement of J in the regulation of meristem fate is consistent with the roles of its closest homologs in Arabidopsis, AGAMOUS LIKE 24 (AGL24) and SHORT VEGETATIVE PHASE (SVP). Our goal is to identify J targets in order to unravel its multiple functions in the tomato inflorescence. [less ▲]

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See detailNatural and induced loss of function mutations in SlMBP21 MADS-box gene led to jointless-2 phenotype in tomato
Gomez Roldan, Maria Victoria; Périlleux, Claire ULiege; Morin, Halima et al

in Scientific Reports (2017), 7

Abscission is the mechanism by which plants disconnect unfertilized flowers, ripe fruits, senescent or diseased organs from the plant. In tomato, pedicel abscission is an important agronomic factor that ... [more ▼]

Abscission is the mechanism by which plants disconnect unfertilized flowers, ripe fruits, senescent or diseased organs from the plant. In tomato, pedicel abscission is an important agronomic factor that controls yield and post-harvest fruit quality. Two non-allelic mutations, jointless (j) and jointless-2 (j-2), controlling pedicel abscission zone formation have been documented but only j-2 has been extensively used in breeding. J was shown to encode a MADS-box protein. Using a combination of physical mapping and gene expression analysis we identified a positional candidate, Solyc12g038510, associated with j-2 phenotype. Targeted knockout of Solyc12g038510, using CRISPR/Cas9 system, validated our hypothesis. Solyc12g038510 encodes the MADS-box protein SlMBP21. Molecular analysis of j-2 natural variation revealed two independent loss-of-function mutants. The first results of an insertion of a Rider retrotransposable element. The second results of a stop codon mutation that leads to a truncated protein form. To bring new insights into the role of J and J-2 in abscission zone formation, we phenotyped the single and the double mutants and the engineered alleles. We showed that J is epistatic to J-2 and that the branched inflorescences and the leafy sepals observed in accessions harboring j-2 alleles are likely the consequences of linkage drags. [less ▲]

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See detailLes mystères de la floraison
Périlleux, Claire ULiege

Conference given outside the academic context (2017)

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See detailUsing a Structural Root System Model to Evaluate and Improve the Accuracy of Root Image Analysis Pipelines
Lobet, Guillaume; Koevoets, Iko; Noll, Manuel ULiege et al

in Frontiers in Plant Science (2017), 8

Root system analysis is a complex task, often performed with fully automated image analysis pipelines. However, the outcome is rarely verified by ground-truth data, which might lead to underestimated ... [more ▼]

Root system analysis is a complex task, often performed with fully automated image analysis pipelines. However, the outcome is rarely verified by ground-truth data, which might lead to underestimated biases. We have used a root model, ArchiSimple, to create a large and diverse library of ground-truth root system images (10,000). For each image, three levels of noise were created. This library was used to evaluate the accuracy and usefulness of several image descriptors classically used in root image analysis softwares. Our analysis highlighted that the accuracy of the different traits is strongly dependent on the quality of the images and the type, size and complexity of the root systems analysed. Our study also demonstrated that machine learning algorithms can be trained on a synthetic library to improve the estimation of several root system traits. Overall, our analysis is a call to caution when using automatic root image analysis tools. If a thorough calibration is not performed on the dataset of interest, unexpected errors might arise, especially for large and complex root images. To facilitate such calibration, both the image library and the different codes used in the study have been made available to the community. [less ▲]

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See detailInflorescence development in tomato
Périlleux, Claire ULiege

Scientific conference (2016, December 02)

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See detailMaize plants can enter a standby mode to cope with chilling stress
Riva-Roveda, Laetitia ULiege; Escale, Brigitte; Giauffret, Catherine et al

in BMC Plant Biology (2016), 16

Background European Flint maize inbred lines are used as a source of adaptation to cold in most breeding programs in Northern Europe. A deep understanding of their adaptation strategy could thus provide ... [more ▼]

Background European Flint maize inbred lines are used as a source of adaptation to cold in most breeding programs in Northern Europe. A deep understanding of their adaptation strategy could thus provide valuable clues for further improvement, which is required in the current context of climate change. We therefore compared six inbreds and two derived Flint x Dent hybrids for their response to one-week at low temperature (10°C day/7 or 4°C night) during steady-state vegetative growth. Results Leaf growth was arrested during chilling treatment but recovered fast upon return to warm temperature, so that no negative effect on shoot biomass was measured. Gene expression analyses of the emerging leaf in the hybrids suggest that plants maintained a ‘ready-to-grow’ state during chilling since cell cycle genes were not differentially expressed in the division zone and genes coding for expansins were on the opposite up-regulated in the elongation zone. In photosynthetic tissues, a strong reduction in PSII efficiency was measured. Chilling repressed chlorophyll biosynthesis; we detected accumulation of the precursor geranylgeranyl chlorophyll a and down-regulation of GERANYLGERANYL REDUCTASE (GGR) in mature leaf tissues. Excess light energy was mostly dissipated through fluorescence and constitutive thermal dissipation processes, rather than by light-regulated thermal dissipation. Consistently, only weak clues of xanthophyll cycle activation were found. CO2 assimilation was reduced by chilling, as well as the expression levels of genes encoding phosphoenolpyruvate carboxylase (PEPC), pyruvate orthophosphate dikinase (PPDK), and the small subunit of Rubisco. Accumulation of sugars was correlated with a strong decrease of the specific leaf area (SLA). Conclusions Altogether, our study reveals good tolerance of the photosynthetic machinery of Northern European maize to chilling and suggests that growth arrest might be their strategy for fast recovery after a mild stress. [less ▲]

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See detailUsing a structural root system model for an in-depth assessment of root image analysis pipeline
Lobet, Guillaume ULiege; Koevoets, Iko; Tocquin, Pierre ULiege et al

E-print/Working paper (2016)

Root system analysis is a complex task, often performed using fully automated image analysis pipelines. However, these pipelines are usually evaluated with a limited number of ground-truth root images ... [more ▼]

Root system analysis is a complex task, often performed using fully automated image analysis pipelines. However, these pipelines are usually evaluated with a limited number of ground-truth root images, most likely of limited size and complexity. We have used a root model, ArchiSimple to create a large and diverse library of ground-truth root system images (10.000). This library was used to evaluate the accuracy and usefulness of several image descriptors classicaly used in root image analysis pipelines. Our analysis highlighted that the accuracy of the different metrics is strongly linked to the type of root system analyzed (e.g. dicot or monocot) as well as their size and complexity. Metrics that have been shown to be accurate for small dicot root systems might fail for large dicots root systems or small monocot root systems. Our study also demonstrated that the usefulness of the different metrics when trying to discriminate genotypes or experimental conditions may vary. Overall, our analysis is a call to caution when automatically analyzing root images. If a thorough calibration is not performed on the dataset of interest, unexpected errors might arise, especially for large and complex root images. To facilitate such calibration, both the image library and the different codes used in the study have been made available to the community. [less ▲]

Detailed reference viewed: 53 (4 ULiège)