Variations in the essential oils from ylang-ylang (Cananga odorata [Lam.] Hook f. & Thomson forma genuina) in the Western Indian Ocean islands

in Flavour and Fragrance Journal (2012), 27(5), 356-366

Ylang-ylang essential oil is an important rawmaterial for the fragrance industry. Despite its economic importance, to the best of our knowledge, no study has yet been undertaken to assess the chemical ... [more ▼]

Ylang-ylang essential oil is an important rawmaterial for the fragrance industry. Despite its economic importance, to the best of our knowledge, no study has yet been undertaken to assess the chemical polymorphism of the different production areas. This underestimated variability is an interesting source of raw material for perfumers. That is why the variation in the chemical composition of four fractions of the essential oils extracted from Cananga odorata, grown in four locations Grande Comore, Mayotte, Nossi Bé and Ambanja, was studied. A total of 119 compounds, representing 85.7–96.4%of the total essential oil composition, were identified using gas chromatography–mass spectrometry and quantified by gas chromatography with a flame ionization detector. Thirty-two compounds previously unreported in ylang-ylang essential oil were identified. The distinction between the Comoros and Madagascar groups wasmade on the basis of the chemical classes. It was possible to significantly distinguish the Grande Comore and Mayotte essential oil samples, as well as the Ambanja and Nossi Bé essential oil samples, on the basis of their main compounds. The aromatic compounds profile for the origin of each essential oil fraction was established. <br />Regression trees were built, allowing the provenance of the essential oils prepared at the laboratory level to be easily differentiated on the basis of a limited number of major compounds. [less ▲]

Effect of a fungal infection on the profile of volatile organic compounds emitted by plant roots

in Communications in Agricultural and Applied Biological Sciences (2012), 77(3), 125-129

Optimization and scaling up of a biotechnological synthesis of natural green leaf volatiles using Beta vulgaris hydroperoxide lyase

in Process Biochemistry (2012), 47

A non-canonical caleosin from Arabidopsis efficiently epoxidizes physiological unsaturated fatty acids with complete stereoselectivity

in FEBS Journal (2012), 279

Describing and modelling root and shoot growth and development in Brachypodium distachyon (L.) Beauv

Poster (2011, October 19)

Due to its small size, its short developmental cycle and its close phylogenetic relationship with the Triticeae tribe, Brachypodium distachyon (L.) Beauv. has been proposed as a model species for ... [more ▼]

Due to its small size, its short developmental cycle and its close phylogenetic relationship with the Triticeae tribe, Brachypodium distachyon (L.) Beauv. has been proposed as a model species for temperate cereals. In this context, this work aims to describe and model root and shoot growth and development of B. distachyon (Bd21-1) grown under controlled environmental conditions [22°C, 65% RH, 20h light, 95 µmol.m-2.s-1 (PAR, LED lighting)]. For this purpose, vernalized caryopses were sown in a substrate consisting of vermiculite and compost (80/20, v/v). Growth and development of the above and belowground parts were monitored for 70 days. Dry and fresh masses of plant organs were measured every seven days from sowing. Biomasses of adventitious and seminal roots were measured separately. The number of spikelets on the main stem and on tillers was also counted on plants aged of 70 days. The modelling of root and shoot growth was achieved by calibrating sigmoidal growth models to the mean biomass values measured at each day of analysis. For each plant organ, the growth model selected was the one with the lowest residual variance. Finally, developmental stages identified for B. distachyon were compared with those defined for cereal crops by Zadoks et al. (1974). Maximum rates of fresh and dry shoot biomass production were 29,5 and 14,2 mg.day-1 respectively. Based on modelling, these values seem to be reached 49 and 72 days after sowing. Results also show that the fresh mass of adventitious roots at day 42 is significantly higher than that of seminal roots. Maximum rates of fresh and dry root biomass production were 6,9 and 0,8 mg.day-1 respectively, and were reached after 37 and 43 days. [less ▲]

Les volatils racinaires de l’orge: un langage souterrain entre plantes?

Poster (2011, October 13)

Interactions volatiles entre les racines d’orge et quelques agents pathogènes

Poster (2011, October 13)

Volatile organic compounds of the roots of barley and their role in the rhizosphere

Poster (2011, May 24)

Volatile organic compounds emitted by plants are known to intervene with various biotic environmental factors. Up to now, most of the studies have been focused on aerial volatiles and root liquid exudates ... [more ▼]

Volatile organic compounds emitted by plants are known to intervene with various biotic environmental factors. Up to now, most of the studies have been focused on aerial volatiles and root liquid exudates. Very few researches have been completed concerning belowground volatiles released into the rhizosphere despite their potential capacity to carry information between organisms. The Rhizovol project, started in autumn 2010, involves 5 different units of Gembloux Agro-Bio Tech collectively studying the production of belowground volatiles by barley roots underlying various biotic interactions in the rhizosphere. Some preliminary results of each partner of the project will be presented. To achieve this goal, analytical methods allowing the sampling, separation, identification and quantification of belowground volatile compounds have to be developed, taking into account their potential modifications in the rhizosphere once released by the roots. They enable the subsequent characterization and study of the interactions between barley and its rhizospheric partners chosen for this study. These interactions imply three types of organisms: beneficial organisms, pathogenic agents and plant and insect pests. Beneficial organisms can promote the growth of barley by the emission of volatiles; on the other hand barley can support their growth and metabolism. These phenomenons will be assessed by the study of 19 strains of plant growth-promoting bacteria (PGPR). Three pathogenic agents - two fungi (Fusarium culmorum and Cochliobolus sativus) and one virus (Barley yellow dwarf virus) - were chosen as they are known to cause various diseases on barley, especially on roots. The attractive or repellent effects of barley root volatiles on the pathogenic agents or their vectors, as well as the effect of volatiles on the diseases evolution will be evaluated. The project also includes several types of pests such as plants and insects. Plants can compete with barley for space and nutrients through volatile interactions. This will be assessed by the study of autotoxicity by barley itself and allelopathy with 8 weeds and a hemiparasitic plant (Rhinanthus minor). The effects of barley volatiles can also impact the severity of the attacks by insects. This part will be conducted with wireworms as they represent worldwide known pests, and aphids, through their viral vector role. Eventually, as soil characteristics can strongly influence the diffusion of volatile compounds, the diffusion behaviour of the identified volatile biomolecules through the soil will be modelled. Tritrophic interactions (e.g. insect-plant-pathogenic fungi) will be studied based on each bitrophic interaction results. Over-all, the Rhizovol project aims at improving the knowledge of interactions mediated by volatile compounds in the rhizosphere and at establishing new biocontrol methods that could contribute to integrated disease and pest management systems. [less ▲]

Volatile organic compounds of the barley rhizosphere and their roles in biotic interactions with plant growth- promoting bacteria, phytopathogens and insect pests

Poster (2011, April 04)

Rapport final d'évaluation du projet APEFE "soutien au laboratoire du Commerce intérieur" de Dakar

Report (2011)