Project description
Insight into sphingolipid metabolism in plants
Sphingolipids are a ubiquitous class of eukaryotic lipids, and in plants they are implicated in various processes such as plasma membrane integrity, cell growth and programmed cell death (PCD) signalling. The EU-funded SMFP project aims to investigate a unique sphingolipid profile encountered in the bryophyte Physcomitrella patens that has proved difficult to study in other model organisms, such as Arabidopsis thaliana. Using a combination of forward and reverse genetics, and newly established analytical and genome editing tools, the researchers will explore the functions of complex sphingolipids and conserved mechanisms that regulate PCD in land plants. The project will offer novel insight into the metabolism and function of sphingolipids and the mechanisms that regulate PCD.
Objective
Sphingolipids are essential lipids that are ubiquitous among eukaryotes. Plants produce structurally diverse sphingolipids that are involved in many processes, including maintenance of plasma membrane integrity and microdomain formation, cell growth and division, polar secretion, and programmed cell death (PCD) signalling. They have primarily been investigated in Arabidopsis thaliana, for which an extensive genetic toolkit has been available for decades. Genome sequences and tools for genome editing are now available for a wide variety of species, offering a better understanding of metabolic and functional diversity, and enabling study of evolutionary history and ancestral functions. The bryophyte Physcomitrella patens is an early-diverged land plant and a relatively new model organism. Preliminary work revealed a unique sphingolipid profile for Physcomitrella, and diversification of gene families associated with the biosynthesis of glycosylinositol phosphorylceramides (GIPCs), the most abundant and diverse class of sphingolipids in plants. The precise functions of GIPCs have been challenging to study in Arabidopsis due to non-viable or pleiotropic mutant phenotypes, complex organ structure, and difficulties with extraction and detection of GIPCs. I propose reverse-genetic characterization of GIPC biosynthesis in Physcomitrella, where expansion of gene families and simple morphology will facilitate mutant analysis. Further, I will use Physcomitrella to dissect the connection between sphingolipid metabolism and PCD, which is well-recognized, but mechanistically obscure. I will perform a mutant screen with Physcomitrella protoplasts for resistance to the ceramide synthase inhibitor and PCD trigger Fumonisin B1. The causal mutations will be identified by next-generation mapping and characterized. Altogether, this work offers novel and unique insight into the metabolism and functions of essential and abundant metabolites, and the mechanisms that regulate PCD.
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Programme(s)
Funding Scheme
MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF)Coordinator
37073 Gottingen
Germany