{"id":781,"date":"2025-11-03T11:45:29","date_gmt":"2025-11-03T10:45:29","guid":{"rendered":"https:\/\/glycobiology-ibsp.org\/research\/"},"modified":"2025-12-10T14:37:57","modified_gmt":"2025-12-10T13:37:57","slug":"research","status":"publish","type":"page","link":"https:\/\/glycobiology-ibsp.org\/en\/research\/","title":{"rendered":"Research"},"content":{"rendered":"\t\t
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Our Research<\/h1>\t\t\t\t<\/div>\n\t\t\t\t
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Research Focused on Reserve Polysaccharide Biology<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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The IBSP team (Integrative Biology of Storage Polysaccharides) <\/strong>conducts its research within the strategic axis \u2018Biomass Polysaccharides\u2019 led by the UGSF laboratory for the 2026\u20132030 period. Our work aims to elucidate the metabolism, structure, and regulation of storage polysaccharides<\/strong>, especially starch, to explore their evolutionary diversity and to understand their responses to abiotic stresses such as temperature and light.
This research takes on its full significance in the context of ecological, food, and energy transitions<\/strong>, where polysaccharides are expected to play a major role in food security, biomass valorization, and the development of sustainable biomaterials<\/strong>.
The work of the IBSP<\/strong> team is organized around four fundamental biological questions, which form the foundation of our scientific approach. <\/p>

In parallel, we develop cross-cutting and exploratory projects, with a strong technological or interdisciplinary component, which enrich our understanding and open up new application perspectives<\/strong>.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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1 \/ Initiation of Starch Synthesis<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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This process involves both the de novo synthesis of carbohydrate chains<\/strong> (priming) and their spatial organization<\/strong> (nucleation) to form a semi-crystalline granule<\/strong>. We study the proteins involved in these early stages. Our approach is based on a diversity of biological models, including storage organs<\/g> (tubers, seeds) from cultivated species such as potato<\/g> or pea<\/g>, as well as green<\/g> and red algae<\/g>, and photosynthetic protists<\/g>. For this, we utilize tools from functional genomics<\/strong>, multi-omics analyses<\/strong>, phylogeny<\/strong>, and comparative biochemistry<\/strong>. <\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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2 \/ Polysaccharide Phase Transition<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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The conversion of soluble glucans into semi-crystalline starch<\/strong>. This complex process involves debranching enzymes (DBEs), but also non-enzymatic proteins such as LESV and ESV1, whose functions remain partly unknown. We also study algal models such as Chromera velia<\/em>, which exhibit alternative crystallization pathways without classical DBEs<\/strong>. This research combines Raman and FT-IR imaging, structural biochemistry, genome editing<\/strong> (CRISPR-Cas9), and single-starch-granule analysis<\/strong> to characterize the composition and fine organization of polysaccharides. <\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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3 \/ Influence of Abiotic Stresses on Starch Metabolism.<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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Temperature<\/strong> is a major environmental signal, modulating photosynthesis<\/strong>, storage<\/strong>, and mobilization of carbon reserves<\/strong>. Our models, such as potato, pea, and certain marine microalgae, allow us to study phenomena such as \u201ccold-induced sweetening<\/g>,\u201d dormancy<\/g> and germination mechanisms<\/g>, or metabolic adaptations under extreme conditions<\/g>. We combine multi-omics analyses<\/strong> (transcriptomics, proteomics, metabolomics), biochemical<\/strong>, and genetic approaches<\/strong> to identify the regulatory networks involved; these approaches are coupled with the use of statistical tools (i.e., the mixOmics R package). <\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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4 \/ Role of Pyrenoidal Starch in Marine Photosymbioses<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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In certain microalgae, starch accumulates around the pyrenoid<\/strong>, a subcellular structure that concentrates CO2 around Rubisco<\/strong>. We study this particular organization using the Symsagittifera roscoffensis\u2013Tetraselmis convolutae<\/g> model, by analyzing isotopic carbon fluxes<\/g> (\u00b9\u00b3C), photosynthesis<\/g> in situ<\/g>, and reconstituted symbioses<\/g> from mutant algae generated by CRISPR<\/g>. This approach allows for a better understanding of the role of starch<\/strong> in the stability and efficiency of alga\u2013animal<\/strong> associations. <\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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Our Cross-Cutting Projects<\/h2>\t\t\t\t<\/div>\n\t\t\t\t
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In parallel with these four biological questions, IBSP<\/strong> conducts a set of cross-cutting and interdisciplinary projects that enrich and extend these themes.<\/p>