References of "Corbesier, Laurent"
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See detailGibberellins and the floral transition in Sinapis alba
Corbesier, Laurent; Kustermans, Gaëlle ULg; Périlleux, Claire ULg et al

in Physiologia Plantarum (2004), 122(1), 152-158

The putative role of gibberellins in the transition to flowering was investigated in Sinapis alba, a caulescent long-day (LD) plant. It was observed that: (1) physiological doses of exogenous gibberellins ... [more ▼]

The putative role of gibberellins in the transition to flowering was investigated in Sinapis alba, a caulescent long-day (LD) plant. It was observed that: (1) physiological doses of exogenous gibberellins (GA(1), GA(3), GA(9)) do not cause the floral shift of the meristem when applied to plants grown in short days but have some positive effect on the flowering response to a suboptimal LD; no inhibition was observed in any case; (2) GA-biosynthesis inhibitors (prohexadione-Ca and paclobutrazol) considerably inhibit stem growth but have some negative effect on flowering only when a suboptimal LD is given; and (3) the floral transition induced by one 22-h LD does not correlate with any detectable change in GA content of the apical bud, of the leaves, and of the phloem exudate reaching the apex. Taken together, these results suggest that GAs do not act as a major signal for photoperiodic flower induction in Sinapis. [less ▲]

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See detailA novel high efficiency, low maintenance, hydroponic system for synchronous growth and flowering of Arabidopsis thaliana.
Tocquin, Pierre ULg; Corbesier, Laurent; Havelange, Andrée ULg et al

in BMC Plant Biology (2003), 3(2), 302003

Background: Arabidopsis thaliana is now the model organism for genetic and molecular plant studies, but growing conditions may still impair the significance and reproducibility of the experimental ... [more ▼]

Background: Arabidopsis thaliana is now the model organism for genetic and molecular plant studies, but growing conditions may still impair the significance and reproducibility of the experimental strategies developed. Besides the use of phytotronic cabinets, controlling plant nutrition may be critical and could be achieved in hydroponics. The availability of such a system would also greatly facilitate studies dealing with root development. However, because of its small size and rosette growth habit, Arabidopsis is hardly grown in standard hydroponic devices and the systems described in the last years are still difficult to transpose at a large scale. Our aim was to design and optimize an up-scalable device that would be adaptable to any experimental conditions. Results: An hydroponic system was designed for Arabidopsis, which is based on two units: a seed-holder and a 1-L tank with its cover. The original agar-containing seed-holder allows the plants to grow from sowing to seed set, without transplanting step and with minimal waste. The optimum nitrate supply was determined for vegetative growth, and the flowering response to photoperiod and vernalization was characterized to show the feasibility and reproducibility of experiments extending over the whole life cycle. How this equipment allowed to overcome experimental problems is illustrated by the analysis of developmental effects of nitrate reductase deficiency in nia1nia2 mutants. Conclusion: The hydroponic device described in this paper allows to drive small and large scale cultures of homogeneously growing Arabidopsis plants. Its major advantages are its flexibility, easy handling, fast maintenance and low cost. It should be suitable for many experimental purposes. [less ▲]

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See detailCytokinin levels in leaves, leaf exudate and shoot apical meristem of Arabidopsis thaliana during floral transition
Corbesier, Laurent; Prinsen, Els; Jacqmard, Annie ULg et al

in Journal of Experimental Botany (2003), 54(392), 2511-2517

Understanding the complete picture of floral transition is still impaired by the fact that physiological studies mainly concern plant species whose genetics is poorly known, and vice versa. Arabidopsis ... [more ▼]

Understanding the complete picture of floral transition is still impaired by the fact that physiological studies mainly concern plant species whose genetics is poorly known, and vice versa. Arabidopsis thaliana has been successfully used to unravel signalling pathways by genetic and molecular approaches, but analyses are still required to determine the physiological signals involved in the control of floral transition. In this work, the putative role of cytokinins was investigated using vegetative plants of Arabidopsis (Columbia) induced to flower synchronously by a single 22 h long day. Cytokinins were analysed in leaf extracts, leaf phloem exudate and in the shoot apical meristem at different times during floral transition. It was found that, in both the leaf tissues and leaf exudate, isopentenyladenine forms of cytokinins increased from 16 h after the start of the long day. At 30 h, the shoot apical meristem of induced plants contained more isopentenyladenine and zeatin than vegetative controls. These cytokinin increases correlate well with the early events of floral transition. [less ▲]

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See detailC : N ratio increases in the phloem sap during floral transition of the long-day plants Sinapis alba and Arabidopsis thaliana
Corbesier, Laurent; Bernier, Georges ULg; Périlleux, Claire ULg

in Plant & Cell Physiology (2002), 43(6), 684-688

In plants of Sinapis alba and Arabidopsis thaliana, leaf exudate (phloem sap) was analysed during and after a single long day inducing flowering and in control short days. The amounts of carbohydrates and ... [more ▼]

In plants of Sinapis alba and Arabidopsis thaliana, leaf exudate (phloem sap) was analysed during and after a single long day inducing flowering and in control short days. The amounts of carbohydrates and amino acids were measured to estimate the organic C : N ratio. In both species, the C : N ratio of the phloem sap increased markedly and early during the inductive treatment, suggesting that an inequality in organic C and N supply to the apical meristem may be important at floral transition. [less ▲]

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See detailThe flowering process: On the track of controlling factors in Sinapis alba
Bernier, Georges ULg; Corbesier, Laurent; Périlleux, Claire ULg

in Russian Journal of Plant Physiology (2002), 49(4, JUL-AUG), 445-450

The major physiological theories of the control of the flowering process are first presented and their inferences tested in the long-day plant Sinapis alba. Then, the genetic analyses of the control of ... [more ▼]

The major physiological theories of the control of the flowering process are first presented and their inferences tested in the long-day plant Sinapis alba. Then, the genetic analyses of the control of flowering time in Arabidopsis thaliana are also summarized with a brief overview of the several pathways, each including several genes, identified. Clearly, both the experimental data of physiological experiments and the multiplicity of interacting genetic pathways best support the theory of the multifactorial control of flowering. This is further shown by the fact that a critical gene expressed in the shoot meristem at floral transition in S. alba, MADS A (orthologous to A. thaliana SOC1), can be upregulated by a single dose of a cytokinin or a gibberellin, without leading to flowering. This indicates that the floral shift requires upregulation of other genes by other factors. [less ▲]

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See detailN content of phloem and xylem exudates during the transition to flowering in Sinapis alba and Arabidopsis thaliana
Corbesier, Laurent; Havelange, Andrée ULg; Lejeune, Pierre et al

in Plant, Cell & Environment (2001), 24

The involvement of nitrogenous substances in the transition to flowering was investigated in Sinapis alba and Arabidopsis thaliana (Columbia). Both species grown in short days (SD) are induced to flower ... [more ▼]

The involvement of nitrogenous substances in the transition to flowering was investigated in Sinapis alba and Arabidopsis thaliana (Columbia). Both species grown in short days (SD) are induced to flower by one long day (LD). In S. alba, the phloem sap (leaf and apical exudates) and the xylem sap (root exudate) were analysed in LD versus SD. In A. thaliana, only the leaf exudate could be analysed but an alternative system for inducing flowering without day-length extension was used: the displaced SD (DSD). Significant results are: (i) in both species, the leaf exudate was enriched in Gln during the inductive LD, at a time compatible with export of the floral stimulus; (ii) in S. alba, the root export of amino acids decreased in LD, whereas the nitrate remained unchanged - thus the extra-Gln found in the leaf exudate should originate from the leaves; (iii) extra-Gln was also found very early in the apical exudate of S. alba in LD, together with more Glu; (iv) in A. thaliana induced by one DSD, the leaf export of Asn increased sharply, instead of Gln in LD. This agrees with Asn prevalence in C-limited plants. The putative role of amino acids in the transition to flowering is discussed. [less ▲]

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See detailChanges in amino acid content during floral induction in the leaf exudate collected form the long day plant Arabidopsis thaliana
Corbesier, Laurent; Lejeune, Pierre; Bernier, Georges et al

Poster (2000)

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See detailPhysiological analysis of the floral transition
Bernier, Georges ULg; Corbesier, Laurent; Périlleux, Claire ULg et al

in Cockshull, K. E.; Gray, D.; Seymour, G. B. (Eds.) et al Genetic and Environmental Manipulation of Horticultural Crops (1998)

This chapter summarizes the changes in contents of the phloem sap that were found at the time of floral induction in different photoperiodic species: Arabidopsis thaliana, Sinapis alba, Lolium temulentum ... [more ▼]

This chapter summarizes the changes in contents of the phloem sap that were found at the time of floral induction in different photoperiodic species: Arabidopsis thaliana, Sinapis alba, Lolium temulentum and Xanthium strumarium. Changes affecting contents in carbohydrates, cytokinins, amino acids, polyamines and inorganis ions are discussed in the context of 'florigen quest'. [less ▲]

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