Plants as sources of energy and chemicals:
Brachypodium distachyon,
a new model system
First French Brachypodium Workshop
September 28th 2009, Versailles
_____________________

In the framework of a program aiming at developing dedicated feedstocks for second generation ligno-cellulosic biofuel production and green chemistry, scientists at the Institute Jean-Pierre Bourgin have adopted Brachypodium distachyon as a novel model species for temperate grasses.

To cope with dwindling fossil oil reserves and greenhouse warming, a major effort is being developed worldwide to use the plant’s capacity to capture and store solar energy as a replacement for fossil oil. In France, cars are already fueled for 5.7 % with first generation biofuel, which is either ethanol produced from wheat or sugarbeet or diesel produced from oilseed rape or sunflower seeds. INRA has started several research programs aiming at developing second generation biofuels, in which the whole ligno-cellulosic biomass of dedicated crops is used rather than only the edible parts of a crop. This should dramatically improve the energy efficiency and limit the environmental impact of the biofuel.

The most promising candidates for dedicated bioenergy feedstocks can be found among the highly productive C4 grasses such as sugarcane, maize, sorgho and not edible perennial grasses such as Miscanthus and switchgrass. Adapting such grass species for the production of biofuel or building blocks for green chemistry will involve maximizing lignocellulosic biomass yield while minimizing environmental impact. In addition, the composition of the biomass should be adapted for the industrial conversion processes. Since the anatomy and biomass composition of grasses is very different from that of dicot species, Arabidopsis has its limitations as a model species and an efficient grass model species is needed.

The First French Brachypodium Workshop has been organized on September 28th 2009 in Versailles as a first step to coordinate the research on this species in France (see program). From this meeting, it became clear that Brachypodium is not only an excellent model for biofuel research but also for seed development, comparative genomics with other cereals, interactions with pathogens and symbionts, evo-devo studies etc.

Brachypodium distachyon is a member of the same botanical subfamily as wheat and barley and has all the attributes of an excellent model species:
- a small plant (20 cm),
- a short generation time (3 months),
- a small genome size (600 x smaller than the wheat genome), fully sequenced in 2009 by a consortium headed by the US Department Of Energy,
- strictly autogamous,
- a very large intraspecies variation.
A large panel of genomic resources are now being developed in several laboratories around the world.

Brachypodium distachyon projects and ressources are being developed at the Institute Jean-Pierre Bourgin (IJPB). IJPB is involved in the INRA project “ALICE”, "Amélioration de la LIgno-CEllulose des graminées" (improvement of the ligno-cellulose of grasses), the european FP7 project “RENEWALL” and the trilateral KBBE project “CELLWALL”. In this framework, IJPB is spearheading the constitution of a Brachypodium Tilling and ecoTilling resource of respectively 10000 families and 160 natural accessions. The first screens for tilling mutants will start early 2010 and the platform will be fully operational and open to the public towards the end of 2010.

Program (.pdf file)

Organizers :
Lise Jouanin (IJPB)
Richard Sibout (IJPB)
Herman Höfte (IJPB, ALICE project coordinator)

To know more about Brachypodium distachyon ressources

octobre 2009

PLANTnet PARIS Symposium

From Plant Genomes to Sustainable Agriculture

October 19th and 20th, 2009, INRA, Versailles

Plant biology laboratories from PLANTnet PARIS organize their second symposium: From Plant Genomes to Sustainable Agriculture. Conferences will cover last scientific developments concerning structures/functions links in plant related to its environment. All the biological ressources (genetics and molecular tools,...) and technological plateforms (genomics, proteomics, metabolomics, cell biology,...) existing within PLANTnet PARIS will be illustrated by posters.

Registration deadline : October 1st, 2009
Limited number of participants, registration is free BUT required on PLANTnet PARIS Website

Programme (.pdf file)

september 2009

European Workshop on Plant Chromatin:
Zurich, September 3rd and 4th, 2009

The European Workshop on Plant Chromatin will cover exciting developments in research on plant chromatin.

The focus will be on chromatin as a biochemical entity, and the two major topics will be:
• (1) Chromatin biochemistry (protein complex composition and activity) and
• (2) Cytology (chromatin dynamics and nuclear architecture).

Program (.pdf file) and report (.pdf file)

Organizers :
Valérie Gaudin (IJPB)
Lars Hennig (ETH Zürich)
Claudia Köhler (ETH Zürich)

For more information, please contact

july 2009

A simple genetic incompatibilty mecanism between individuals shown in the model plant Arabidopsis thaliana could explain appearance of new natural species

The group of Olivier Loudet have just shown that duplication and translocation of a gene in Arabidopsis thaliana genome can generate strains incompatibilities. These new results will have significant impact on the way to consider mechanisms of appearance of new species in plants (speciation). This work has been published in Science (30 janvier 2008) together with a group from the University of Nottingham.

When crossing individuals from same or different species, it is common to observe reduce viability or fertility in the progeny. For a very long time, the more likely interpretation of these incompatibilities was a negative interaction between parental genomes, more precisely genes or alleles. Another interpretation could be a consequence of presence or absence of a gene at different localisations (loci). This mechanism was still to be demonstrated in planta.
Olivier Loudet's group has shown that different Arabidopsis thaliana natural populations have diverged for the position of a gene in the genome. This gene codes for a compound essential for the life of the plante: the aminoacid histidine (HPA gene). The HPA gene is located at two possible loci in Arabidopsis (thale grass) genome: chromosome 1 or 5. Within two populations coming from different regions of the world, one harbours the gene on one chromosome and the second one on the other one.
In crosses between two strains harbouring the HPA gene only on chromosome 1 for one and on the 5th one for the other, by the game of recombinations between parental genomes, some plants in the progeny did not harbour at least a functional copy of the gene. Those individuals are unable to grow. In that case, incompatibility results from the inability for the embryo to develop without at least a functional copy of the gene. Providing histidine restore embryo development showing that its death is a consequence of the inability to produce histidine, due to the absence of the HPA gene. For the first time, the scientific group showed that this phenomenon, linked to duplication and extinction of a gene, can consequently produce allelic incompatibilities between different individuals of a same species.

The rapidity and diversity of natural evolution of these genes is to be noticed. Having the possibility to observe these incompatibilities between individuals of a same species can help to understand how these genes are then fixed and participate to establish barriers of reproduction with recurrence of this mechanism, consequently confining population and leading eventually to speciation.

(*) Bikard et al. (2008). Divergent Evolution of Duplicate Genes Leads to Genetic Incompatibilities within A. thaliana. Science 323 (5914), 623-626 (PubMed) (Abstract | Full Text | PDF)

Contact : Olivier Loudet
The V.A.ST Lab : Variation and Abiotic Stress Tolerance

30 janvier 2009

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