書評論文

Effect of chilling on gene expression in the leaves of two maize hybrids. The 7-day chilling treatment (10 °C day/4 °C night) was applied at about the 6-VL stage. Analyses were performed at the end of the chilling treatment for treated plants or 1 day after the beginning of the treatment for control plants in order to compare plants at the same developmental stage. a and b are biological replicates of Fig. 6. Data are means ± se of 3 technical replicates. Gene abbreviations: ICE1 (INDUCER OF CBF/DREB EXPRESSION 1), DREB1 (DROUGHT-RESPONSIVE ELEMENT BINDING), CDKA1 (CYCLIN DEPENDENT KINASE A 1), CYCA3 (CYCLIN A 3), KRP1 (CYCLIN-DEPENDENT KINASE INHIBITOR 1), EXPA4 (ALPHA EXPANSIN 4), EXPB2 (BETA EXPANSIN 2), GGR (GERANYLGERANYL REDUCTASE), CAB1 (CHLOROPHYLL A/B BINDING PROTEIN), psbS (CP22 PSII subunit), VDE (VIOLAXANTHIN DE-EPOXIDASE), PEPC (PHOSPHOENOLPYRUVATE CARBOXYLASE), PPDK (PYRUVATE, ORTHOPHOSPHATE DIKINASE) and rbcS (RUBISCO small subunit). (PDF 351 kb

Inflorescence development in tomato: linking gene function with a zigzag model

<p>Tomato is a major crop plant and several mutants have been selected for breeding but also for isolating important genes that regulate flowering and sympodial growth.</p> <p> </p> <p>We developed a kinetic model of the tomato inflorescence development. We exploited the model to explore the diversity of morphotypes that could be generated and matched them with existing mutant phenotypes. This approach, focused on the development of the primary inflorescence, allowed us to elaborate on the genetic regulation of the kinetic model of inflorescence development.</p

Heat can erase epigenetic marks of vernalization in <i>Arabidopsis</i>

<div><p>Vernalization establishes a memory of winter that must be maintained for weeks or months in order to promote flowering the following spring. The stability of the vernalized state varies among plant species and depends on the duration of cold exposure. In <i>Arabidopsis thaliana</i>, winter leads to epigenetic silencing of the floral repressor gene <i>FLOWERING LOCUS C</i> (<i>FLC</i>) and the duration of cold is measured through the dynamics of chromatin modifications during and after cold. The growing conditions encountered post-vernalization are thus critical for the maintenance of the vernalized state. We reported that high temperature leads to devernalization and, consistently, to <i>FLC</i> reactivation in <i>Arabidopsis</i> seedlings. Here we show that the repressive epigenetic mark H3K27me3 decreases at the <i>FLC</i> locus when vernalized seedlings are grown at 30°C, unless they were first exposed to a stabilizing period at 20°C. Ambient temperature thus controls the epigenetic memory of winter.</p></div

Plant image analysis tools: current trends and future challenges

<p>The past decade has seen the apparition of a tremendous amount of plant image analysis tools. This "Golden Age" was born from the conjuncture of two main factors. On the one hand, it was driven by an increasing demand from the plant science community for faithful and reproductible phenotyping data. On the other hand, it was empowered by a greater access to digital sensors and an increase in computer power. As a results, there are now more than 110 tools available for scientists, ranging from the dynamic analysis of cell components to the quantification of tree canopies.</p> <p>Here we propose to make an overview of existing plant image analysis software tools. Taking advantage of the ressources available online on the plant-image-analysis.org database [1], we will analyse the main trends in tool development and present the current limitations and gaps in the domain. In particular, we will highlight the importance of (i) increasing collaboration between plant image analysis groups and (2) the need for plant image validation dataset.</p> <p>[1] Lobet, Draye and Périlleux (2013) Plant Methods 9 (38)</p

Molecular analysis of root medium impact on Arabidopsis thaliana development

Poster presented at the Bioforum 2013 of BioLiège, Liège [Belgium]

Genetic Control of Flowering Time in Arabidopsis: a Comprehensive and Interactive Online Tool

Poster presented at the plant Organ Growth Symposium 2015, Ghent [Belgium]

Additional file 3: Figure S2. of Maize plants can enter a standby mode to cope with chilling stress

Effect of chilling on CO2 assimilation in two maize hybrids. The 7-day chilling treatment (10 °C day/4 °C night) was applied at about the 6-VL stage. Measurements were performed in the middle of 4th leaf blade at the end of the chilling treatment for treated plants or 1 day after the beginning of the treatment for control plants in order to compare plants at the same developmental stage. Ambient parameters were 25 °C, 380 μmol CO2 mol−1. (a) Irradiance response curves of CO2 assimilation. The irradiances used for the measurements were 2000, 1500, 1000, 800, 600, 400, 300, 150 and 0 μmol m−2 s−1 PAR. (b) Curve parameters. Initial slope was calculated between irradiance 0 and 150 μmol m−2 s−1 PAR; compensation point is the irradiance at which CO2 assimilation is 0. Data are means ± sd of 15–20 plants (5–10 individuals in 2 experiments). (PDF 349 kb

Additional file 2: Figure S1. of Maize plants can enter a standby mode to cope with chilling stress

Identification of constitutive genes for RT-qPCR analyses. Ten housekeeping genes (see Additional file 1: Table S1) were tested for constitutive expression in a mix of leaf tissues taken along the developmental gradient of leaf 5 (base, middle and tip) and at the tip of leaf 6 in control and chilled plants. 8–15 plants were pooled for RT-qPCR. A geNormPLUS analysis was performed for the calculation of the M value for each gene. The dotted line indicates the threshold below which the gene is regarded as ‘constitutive’ in this set of samples (geNorm M value < 0.5). Gene abbreviations: ACT1 (ACTIN 1), GPA1 (GLYCERALDEHYDE-3-PHOSPHATE DEHYDROGENASE), TUB (TUBULIN ALPHA 3 CHAIN), EF1A (ELONGATION FACTOR 1 ALPHA), MEP (MEMBRANE PROTEIN), FGP1 (FOLYLPOLYGLUTAMATE SYNTHASE), UBI (UBIQUITIN), LUG (LEUNIG), CUL (CULLIN) and UCE (UBIQUITIN CONJUGATING ENZYME E2). (PDF 311 kb

Inflorescence phenotype of tomato mutants.

<p>(A–C) Ailsa Craig WT; (D) and (E) <i>s</i> mutant; (F) and (G) <i>j</i> mutant; (H) and (I) <i>j∶s</i> double mutant; (J–L) <i>fa</i> mutant; (M–O) <i>s∶fa</i> double mutant; (P) and (Q) <i>j∶fa</i> double mutant. In microscopic pictures, colour bars show the clefts that occurred sequentially when new meristems were initiated to build-up the inflorescence. Red: 1^st; yellow: 2^nd; green: 3^rd; blue: 4^th; purple: 5^th. Dots of same colours show the corresponding branching in macroscopic inflorescence pictures. Pictures K and N zoom in J and M, respectively, to show clumps of IMLs in the inflorescences (arrows). Genotype abbreviations: AC, Ailsa Craig WT; <i>fa</i>, <i>falsiflora</i>; <i>j</i>, <i>jointless</i>; <i>s</i>, <i>compound inflorescence</i>. Annotations: AX, axillary meristem; F, flower; FM, flower meristem; IM, inflorescence meristem; IML, IM-like; L, leaf; SAM, shoot apical meristem; SYM, sympodial meristem; VM, vegetative meristem. Bars = 100 µm except in K and N where bars = 1 mm.</p

A cytokinin route to flowering in Arabidopsis

Poster presented at the workshop on Molecular Mechanisms controlling flower development, Maratea [Italy] in 2011