A5026488882- Photosynthetic Processes and Mechanisms
- Horticultural and Viticultural Research
- Light effects on plants
- Plant responses to elevated CO2
- Plant Water Relations and Carbon Dynamics
- Phytochemicals and Antioxidant Activities
- Plant Stress Responses and Tolerance
- Photoreceptor and optogenetics research
- Remote Sensing in Agriculture
- Fermentation and Sensory Analysis
- Plant and animal studies
- Plant Pathogens and Fungal Diseases
- Plant Gene Expression Analysis
- Leaf Properties and Growth Measurement
- Spectroscopy and Chemometric Analyses
- Spectroscopy and Quantum Chemical Studies
- Algal biology and biofuel production
- Marine and coastal ecosystems
- Remote Sensing and LiDAR Applications
- Antioxidant Activity and Oxidative Stress
- Plant biochemistry and biosynthesis
- Powdery Mildew Fungal Diseases
- Cynara cardunculus studies
- Biocrusts and Microbial Ecology
- Crop Yield and Soil Fertility
Centre National de la Recherche Scientifique
2011-2020
Écologie, Systématique et Évolution
2011-2020
Université Paris-Sud
2010-2019
AgroParisTech
2009-2019
Université Paris-Saclay
1992-2019
Nello Carrara Institute of Applied Physics
2005-2007
Université Paris Cité
1993-2006
Ecologie & Evolution
2006
Estación Experimental de Aula Dei
2005
University of Florence
2005
We have characterized a new commercial chlorophyll (Chl) and flavonoid (Flav) meter called Dualex 4 Scientific (Dx4). compared this device to two other Chl meters, the SPAD-502 CCM-200. In addition, Dx4 was leaf-clip 3 that measures only epidermal Flav. is factory-calibrated provide linear response increasing leaf content in units of µg cm(-2), as opposed both CCM-200 non-linear content. Our comparative calibration by extraction confirmed these responses. It seems derives from use 710 nm...
Abstract In this study a method was designed to assess non‐destructively the type of UV‐screening compounds present in leaf epidermis. The is based on recording and calculation ratio UV‐excitation spectra chlorophyll fluorescence (FER) from adaxial abaxial sides bifacial leaves, or older younger segments monocotyledonous leaves. logarithm (logFER) matched absorption spectrum UV‐absorbers leaf, as confirmed by its overlap with methanolic extract isolated By using logFER approach, it possible...
Dualex (dual excitation) is a field-portable instrument, hereby described, for the assessment of polyphenolic compounds in leaves from measurement UV absorbance leaf epidermis by double excitation chlorophyll fluorescence. The instrument takes advantage feedback loop that equalizes fluorescence level induced reference red light to UV-light-induced level. This allows quick attached even under field conditions. use light-emitting diodes and leaf-clip configuration makes user-friendly with...
A new, commercial, fluorescence-based optical sensor for plant constituent assessment was recently introduced. This sensor, called the Multiplex® (FORCE-A, Orsay, France), used to monitor grape maturation by specifically monitoring anthocyanin accumulation. We derived empirical content calibration curves Champagne red cultivars, and we also propose a general model influence of proportion berries, skin berry size on indices. The both samples in laboratory intact clusters vineyard. found that...
Crop nitrogen status is a major issue for crop yield and quality. It usually assessed by destructive leaf or petiole tissue analysis. A quantitative nondestructive optical estimation of N sufficiency would be great leap forward toward precision management. We therefore calibrated three indices against content: chlorophyll (Chl), epidermal flavonols, the balance index (NBI), which ratio former two indices. NBI was best estimator content measured Dumas Kjeldahl method with root-mean-square...
ABSTRACT Chlorophyll (Chl) and epidermal polyphenol (EPhen) contents were estimated in vivo using two optical leaf‐clips, SPAD‐502 Dualex, respectively. The area‐based measurements transformed into mass‐based data by taking account the leaf dry mass per area (LMA). Measurements performed on forest trees saplings grown under controlled conditions. While LMA increased with irradiance along a vertical transect beech canopy or different increasing levels, EPhen (EPhen m ) increased, whereas Chl...
The resistance of maize plants to cold stress has been associated with the appearance a new chlorophyll a/b binding protein in thylakoid membrane following chilling treatment light. cold-induced isolated, characterized by amino acid sequencing, and pulse labeled radioactive precursors, showing that it is product post-translational modification phosphorylation minor CP29 rather than cold-regulated gene or an unprocessed precursor. We show here kinase activity displays unique characteristics...
The effect of leaf temperature (T), between 23 and 4°C, on the chlorophyll (Chl) fluorescence spectral shape was investigated under moderate (200 μE m−2 s−1) low (30–35 light intensities in Phaseolus vulgaris Pisum sativum. With decreasing temperature, an increase yield at both 685 735 nm observed. A marked change occurred longer emission band resulting a decrease Chl ratio, F685/F735, with reducing T. Our analysis suggests that this is due to temperature-induced state 1–state 2 transition...
Interactions between photosynthesis, mitochondrial respiration (mitorespiration), and chlororespiration have been investigated in the green alga Chlamydomonas reinhardtii using flash illumination a bare platinum electrode. Depending on physiological status of algae, was found to induce either fast (t(1/2) approximately 300 ms) or slow 3 s) transient inhibition oxygen uptake. Based effects mitorespiratory inhibitors myxothiazol salicyl hydroxamic acid (SHAM), propyl gallate, an inhibitor...
Anthocyanins (Anths) in grape (Vitis vinifera L.) berries harvested at véraison from Pinot Noir and Meunier cultivars were assessed nondestructively by measuring chlorophyll fluorescence (ChlF) excitation spectra. With increasing Anth content, less light was transmitted to the deeper Chl layers, thus ChlF signal decreased proportionally. By applying Beer−Lambert's law, logarithm of ratio between spectra (log FER) a green red berry gave vivo absorption spectrum Anths, which peaked about 540...
An improved procedure for the mechanical isolation of chloroplasts high degree intactness (90-95%) and photosynthetic capacity (25-50 mmol O2/s per mol chlorophyll) is described. The combination pea plants (Pisum sativum L.) as starting material reproducibility readily cheaply yields reliable intact studies.