Molecular mechanism of chrysolaminaran synthesis in diatoms

Mariia Molchanova

Chrysolaminaran is the principal energy storage polysaccharide of diatoms. It plays a significant role in the oceanic cycling of carbon. It was localized in vacuoles in diatoms. According to the current research the putative genes involved in Chrysolaminaran synthesis pathway have been predicted in both Phaeodactylum tricornutum and Thalassiosira pseudonana. UDP-glucose catalysed by UDP-glucose pyrophosphorylase (UDPG) is the main form of activated sugar and the major glucosyl donor for carbohydrates in plants. Two UDPG isoforms exist in P. tricornutum, and they were predicted in the cytosol and plastids respectively. One single 1,3-β-glucan synthase and three isoforms of 1,6-β-transglucosylases were identified in P. tricornutum. But the formation pathway of chrysolaminaran is still unclear such as where these proteins are located and how the chrysolaminaran in vacuoles is synthesized from glucose in plastids. The aims of my research are subcellular localizations of these proteins and determination of these proteins functions.