prof. Aharoni's seminar
Venerdì, 04 Ottobre 2019 dalle ore 11:00 alle ore 12:00
Room 6302 PRC building
TITLE: Hijacking GAMEs: Evolution and Domestication of the Alkaloids Pathway in the Genus Solanum
SPEAKER: Prof. Asaph Aharoni, Department of Plant & Environmental Sciences, Faculty of Biochemistry, Weizmann Institute of Science, P.O.B. 26, Rehovot, 7610001, Israel
ABSTRACT: The Metabolomes of plant are notorious for their size and structural diversity. Secondary metabolites represent a large portion of this metabolic repertoire counting thousands in an individual plant. Generating such chemical complexity in secondary metabolism requires continues evolution of genes encoding proteins producing novel metabolites with selective advantage in a particular environmental niche. Genes with new function in secondary metabolism could arise from other genes of secondary metabolism, through gene duplication or directly through allelic variation. Yet, likely often, they arise following duplication of genes involved in primary metabolites formed across all species. In the past years we discovered a series of enzymes, regulatory and signalling proteins as well as transporters involved in steroidal GlycoAlkaloids MEtabolism (GAME) in the genus Solanum. This class of secondary metabolites represents potent defence molecules with notorious anti-nutritional activity towards humans (e.g. α-Solanine in potato). In the presentation, I will portray several different molecular mechanisms wherein genes of core, primary metabolic pathways (e.g. membrane sterols metabolism and the GABA shunt) were ‘hijacked’, providing a template for the evolution of new enzymatic functions in glycoalkaloid metabolism. This will be complemented by examples of chemical diversity formed following neofunctionalization of genes derived from highly related, secondary metabolism genes. Selected alleles involved in generating secondary metabolites having beneficial attributes to mankind where part of the domestication of Solanum crop plants (e.g. tomato and potato) cultivated today. The case of steroidal glycoalkaloids is most likely a common evolutionary strategy of plants by which the chemical diversity of secondary metabolism has been endlessly revised.
HOST: Fabrizio Costa