References of "New Phytologist"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailPSI Mehler reaction is the main alternative photosynthetic electron pathway in Symbiodinium sp., symbiotic dinoflagellates of cnidarians
Roberty, Stéphane ULg; Bailleul, Benjamin ULg; Berne, Nicolas et al

in New Phytologist (in press)

• Photosynthetic organisms have evolved various photoprotective and regulatory mechanisms to cope with changing and high light intensities. The nature and relative amplitude of these mechanisms is matter ... [more ▼]

• Photosynthetic organisms have evolved various photoprotective and regulatory mechanisms to cope with changing and high light intensities. The nature and relative amplitude of these mechanisms is matter of debate in dinoflagellates that live in symbiosis with cnidarians. In this work, the amplitude of photosynthetic alternative electron flows to oxygen (chlororespiration, Mehler reaction, mitochondrial respiration) and PSI cyclic electron flow were investigated in Symbiodinium clades A1, B1 and F1. • Cultured Symbiodinium strains were maintained semi-continuously under identical environmental conditions. Joint measurements of oxygen evolution, fluorescence emission, and absorption changes at specific wavelengths were used to evaluate PSI and PSII electron transfer rates (ETR). • A light-dependent and O2-dependent ETR was observed in all strains. This ETR involved PSII and PSI and was insensitive to addition of mitochondrial and carbon fixation inhibitors. • These results demonstrate that photoreduction of oxygen downstream of PSI by the so-called Mehler reaction is the main alternative electron sink at the onset and steady state of photosynthesis in all strains. This mechanism in Symbiodinium sustains significant levels of photosynthetic electron flux under high light, thus acting as a photoprotective mechanism and increasing the ATP/NADPH ratio by the electron transfer chain. [less ▲]

Detailed reference viewed: 32 (8 ULg)
Full Text
Peer Reviewed
See detailThe anagenetic world of spore-producing land plants.
Patino Llorente, Jairo; Carine, M.A.; Fernández-Palacios, J.M. et al

in New Phytologist (2014), 201

Detailed reference viewed: 7 (0 ULg)
Full Text
Peer Reviewed
See detailThe anagenetic world of spore-producing land plants
Patino Llorente, Jairo ULg; Carine, M.A.; Fernández-Palacios, J.M. et al

in New Phytologist (2014), 201

Detailed reference viewed: 9 (0 ULg)
Full Text
Peer Reviewed
See detailThermal optimality of net ecosystem exchange of carbon dioxide and underlying mechanisms
Niu, Shuli; Fei, Shenfeng; Yuan, Wenping et al

in New Phytologist (2012), 194

• It is well established that individual organisms can acclimate and adapt to temperature to optimize their functioning. However, thermal optimization of ecosystems, as an assemblage of organisms, has not ... [more ▼]

• It is well established that individual organisms can acclimate and adapt to temperature to optimize their functioning. However, thermal optimization of ecosystems, as an assemblage of organisms, has not been examined at broad spatial and temporal scales. • Here, we compiled data from 169 globally distributed sites of eddy covariance and quantified the temperature response functions of net ecosystem exchange (NEE), an ecosystem- level property, to determine whether NEE shows thermal optimality and to explore the underlying mechanisms. • We found that the temperature response of NEE followed a peak curve, with the optimum temperature (corresponding to the maximum magnitude of NEE) being positively correlated with annual mean temperature over years and across sites. Shifts of the optimum temperature of NEE were mostly a result of temperature acclimation of gross primary productivity (upward shift of optimum temperature) rather than changes in the temperature sensitivity of ecosystem respiration. • Ecosystem-level thermal optimality is a newly revealed ecosystem property, presumably reflecting associated evolutionary adaptation of organisms within ecosystems, and has the potential to significantly regulate ecosystem–climate change feedbacks. The thermal optimality of NEE has implications for understanding fundamental properties of ecosystems in changing environments and benchmarking global models. [less ▲]

Detailed reference viewed: 11 (4 ULg)
Full Text
Peer Reviewed
See detailEvolution of sexual systems, dispersal strategies and habitat selection in the liverwort genus Radula
Devos, Nicolas ULg; Renner, Matt; Gradstein, Robbert et al

in New Phytologist (2011), 192(1), 225-236

Detailed reference viewed: 71 (21 ULg)
Full Text
Peer Reviewed
See detailEarly Middle Ordovician evidence for land plants in Argentina (eastern Gondwana)
Rubinstein, C. V.; Gerrienne, Philippe ULg; de la Puente, G. S. et al

in New Phytologist (2010), 188

Detailed reference viewed: 123 (17 ULg)
Full Text
Peer Reviewed
See detailMacroecological patterns of genetic structure and diversity in the aquatic moss Platyhypnidium riparioides
Hutsemekers, Virginie ULg; Hardy, O. J.; Mardulyn, P. et al

in New Phytologist (2010)

Detailed reference viewed: 67 (13 ULg)
Full Text
Peer Reviewed
See detailVernalization-induced repression of FLOWERING LOCUS C stimulates flowering in Sinapis alba and enhances plant responsiveness to photoperiod.
D'Aloia, Maria ULg; Tocquin, Pierre ULg; Périlleux, Claire ULg

in New Phytologist (2008), 178(4), 755-65

Of the Brassicaceae, Sinapis alba has been intensively studied as a physiological model of induction of flowering by a single long day (LD), while molecular-genetic analyses of Arabidopsis thaliana have ... [more ▼]

Of the Brassicaceae, Sinapis alba has been intensively studied as a physiological model of induction of flowering by a single long day (LD), while molecular-genetic analyses of Arabidopsis thaliana have disclosed complex interactions between pathways controlling flowering in response to different environmental cues, such as photoperiod and vernalization. The vernalization process in S. alba was therefore analysed here. The coding sequence of S. alba SaFLC, which is orthologous to the A. thaliana floral repressor FLOWERING LOCUS C, was isolated and the transcript levels quantified in different conditions. Two-week-old seedlings grown in noninductive short days (SDs) were vernalized for 1-6 wk. Down-regulation of SaFLC was already marked after 1 wk of cold but 2 wk was needed for a significant acceleration of flowering. Flower buds were initiated during vernalization. When vernalization was stopped after 1 wk, repression of SaFLC was not stable but a significant increase in plant responsiveness to 16-h LDs was observed when LDs followed immediately after the cold treatment. These results suggest that vernalization does not only work when plants experience long exposure to cold during the winter: shorter cold periods might stimulate flowering of LD plants if they occur when photoperiod is increasing, such as in spring. [less ▲]

Detailed reference viewed: 67 (34 ULg)
Full Text
Peer Reviewed
See detailLeaf carbohydrate controls over Arabidopsis growth and response to elevated CO2: an experimentally based model
Rasse, Daniel; Tocquin, Pierre ULg

in New Phytologist (2006), 172(3), 500-513

Transient starch production is thought to strongly control plant growth and response to elevated CO2. We tested this hypothesis with an experimentally based mechanistic model in Arabidopsis thaliana ... [more ▼]

Transient starch production is thought to strongly control plant growth and response to elevated CO2. We tested this hypothesis with an experimentally based mechanistic model in Arabidopsis thaliana. Experiments were conducted on wild-type (WT) A. thaliana, starch-excess (sex1) and starchless (pgm) mutants under ambient and elevated CO2 conditions to determine parameters and validate the model. The model correctly predicted that mutant growth is approx. 20% of that in WT, and the absolute response of both mutants to elevated CO2 is an order of magnitude lower than in WT. For sex1, direct starch unavailability explained the growth responses. For pgm, we demonstrated experimentally that maintenance respiration is proportional to leaf soluble sugar concentration, which gave the necessary feedback mechanism on modelled growth. Our study suggests that the effects of sugar-starch cycling on growth can be explained by simple allocation processes, and the maximum rate of leaf growth (sink capacity) exerts a strong control over the response to elevated CO2 of herbaceous plants such as A. thaliana. [less ▲]

Detailed reference viewed: 36 (6 ULg)
Full Text
Peer Reviewed
See detailDesign of a versatile device for measuring whole plant gas exchanges in Arabidopsis thaliana
Tocquin, Pierre ULg; Périlleux, Claire ULg

in New Phytologist (2004), 162(1), 223-229

Because of its small size and rosette growth habit, measuring gas exchanges in Arabidopsis thaliana is difficult with standard leaf cuvettes. Here, we designed a versatile system that is usable at the ... [more ▼]

Because of its small size and rosette growth habit, measuring gas exchanges in Arabidopsis thaliana is difficult with standard leaf cuvettes. Here, we designed a versatile system that is usable at the whole rosette level, as small as possible for fast and accurate measurements, but adaptable to plant size, and suitable for in situ measurements whatever the growing substrate of the plant. This cuvette is in two parts: the basic unit, which contains the sensors and is connected to the infra-red gas analyzer, and the clear chamber, where the rosette is enclosed. We made a set of three interchangeable chambers of different sizes to measure the rate of CO2 assimilation [A] of 26-, 33- and 40-d-old plants. The dependence of A to light irradiance and to intercellular CO2 concentration was recorded as typical response curves, which validate our device. Measurements were not only consistent in saturating conditions, but accurate CO2 exchange measurements in limiting conditions also reflected important physiological features related to plant ageing. [less ▲]

Detailed reference viewed: 23 (3 ULg)
Full Text
Peer Reviewed
See detailChlamydomonas reinhardtii as a eukaryotic photosynthetic model for studies of heavy metal homeostasis and tolerance
Hanikenne, Marc ULg

in New Phytologist (2003), 159(2), 331-340

The green alga Chlamydomonas reinhardtii is a useful model of a photosynthetic cell. This unicellular eukaryote has been intensively used for studies of a number of physiological processes such as ... [more ▼]

The green alga Chlamydomonas reinhardtii is a useful model of a photosynthetic cell. This unicellular eukaryote has been intensively used for studies of a number of physiological processes such as photosynthesis, respiration, nitrogen assimilation, flagella motility and basal body function. Its easy-to-manipulate and short life cycle make this organism a powerful tool for genetic analysis. Over the past 15 yr, a dramatically increased number of molecular technologies (including nuclear and organellar transformation systems, cosmid, yeast artificial chromosome (YAC) and bacterial artificial chromosome (BAC) libraries, reporter genes, RNA interference, DNA microarrays, etc.) have been applied to Chlamydomonas . Moreover, as parts of the Chlamydomonas genome project, molecular mapping, as well as whole genome and extended expressed sequence tag (EST) sequencing programs, are currently underway. These developments have allowed Chlamydomonas to become an extremely valuable model for molecular approaches to heavy metal homeostasis and tolerance in photosynthetic organisms. [less ▲]

Detailed reference viewed: 201 (3 ULg)
Full Text
Peer Reviewed
See detailEcological, morphological and allozymic differentiation between diploid and tetraploid knapweeds (Centaurea jacea) from a contact zone in the Belgian Ardennes
Hardy, O. J.; Vanderhoeven, SONIA ULg; De Loose, M. et al

in New Phytologist (2000), 146(2), 281-290

In the northeastern part of Belgium, the Centaurea jacea complex shows extensive morphological variation and is represented by a diploid (2n = 22) and a tetraploid (2n = 44) cytotype. Polysomic ... [more ▼]

In the northeastern part of Belgium, the Centaurea jacea complex shows extensive morphological variation and is represented by a diploid (2n = 22) and a tetraploid (2n = 44) cytotype. Polysomic inheritance of allozyme markers in the tetraploids, suggesting autopolyploidy, is here demonstrated for the first time. In order to test whether the tno cytotypes occupy distinct habitats and possess different gene pools, patterns of allozymic and morphological variation were investigated in relation to ploidy level and site characteristics in 26 populations from the Belgian Ardennes. The two cytotypes showed a parapatric distribution, the diploids occurring at higher elevations (mostly above 500 m) than the tetraploids (mostly below 500 m). Three mixed populations were found near the contact zone of the two cytotypes. Within the mixed populations no triploid plant and no evidence for gene flow between cytotypes were found, despite widely overlapping flowering periods. The two cytotypes can be distinguished on the basis of morphological traits and enzymatic gene pools. The congruence of morphological and allozymic variation with chromosome numbers suggests a secondary contact between the two cytotypes with limited gene flow between them. The origin and persistence of the parapatric distribution are discussed. [less ▲]

Detailed reference viewed: 14 (0 ULg)
Full Text
Peer Reviewed
See detailLeaf carbohydrate status in Lolium temulentum during the induction of flowering
Périlleux, Claire ULg; Bernier, Georges ULg

in New Phytologist (1997), 135(1), 59-66

Unifoliated plants of Lolium temulentum L. ev. Ceres, a qualitative long-day grass, were induced to flower by one 24-h long day (LD) or by one 8-h short day (SD) advanced by 1 2 h in the normal regime, so ... [more ▼]

Unifoliated plants of Lolium temulentum L. ev. Ceres, a qualitative long-day grass, were induced to flower by one 24-h long day (LD) or by one 8-h short day (SD) advanced by 1 2 h in the normal regime, so-called 'displaced short day' (DSD). Standard light for SD and DSD was a mixture of fluorescence and incandescence at 400 µmol m2 s-1 whereas the extension period of the 24-h LD was solely incandescence at 10-15 µmol m2 s-1. The DSD system was first characterized by the timings of floral induction, stimulus translocation and apical development. Carbohydrates in the blade tissues and in leaf exudate were analysed comparatively in vegetative and induced plants. Fructans were not detected in the leaf tissues whereas sucrose and starch were found to be present in similar amounts. In SD, their contents exhibited a diurnal fluctuation and were not in large excess. The common change observed during the two inductive treatments was that starch remained at a high level during the LD extension, even though the lighting was unsuitable for photosynthesis, and increased transiently in DSD. Sucrose was the major sugar contained in the leaf exudate. Its content increased when flowering was induced, but not at the same time in the two systems. In LD, sucrose exudation rose when plants were returned to standard light after the inductive cycle, i.e. after the LD stimulus had left the leaf blade. By contrast, during the DSD, sucrose was transported at the same time as the floral stimulus. Results are discussed together with the methods used to time stimulus translocation and their implications. [less ▲]

Detailed reference viewed: 34 (4 ULg)
Peer Reviewed
See detailAllozyme diversity and genetic structure in South - Western populations of Heather, Calluna vulgaris (L.) Hull
Mahy, Grégory ULg; Vekemans, Xavier; Jacquemart, Anne Laure et al

in New Phytologist (1997), 137

Detailed reference viewed: 10 (1 ULg)