In this study we have identified and characterized three
In this study, we have identified and characterized three sunflower ENO isoforms. We surveyed the expression of ENO genes and the subcellular localization of the corresponding protein products. Recombinant ENO proteins were expressed in Escherichia coli in order to determine their kinetic properties. Similarly, to the situation observed in A. thaliana, we found that one the three ENO proteins did not have catalytic activity. Site directed mutagenesis was used to recover low levels of activity for this protein. These data extend our understanding of the contribution of ENO isoforms to the conversion of 2-PGA to PEP in the cytosolic and plastidial compartments of sunflower seeds during fatty apomorphine synthesis. Our results are discussed in relation to a model that recapitulates current knowledge on the importance of the glycolytic pathway in sunflower seed filling.
Materials and methods
Discussion In developing seeds, glycolysis is the paramount metabolic pathway in which hexoses are converted to Pyr that is subsequently being used as a source of carbon for fatty acids biosynthesis within plastids. PEP, the product of ENO activity, is the immediate precursor of Pyr and therefore plays a key biochemical function during lipid deposition. ENO is a ubiquitous enzyme that is present in the plant cytosolic and plastidial compartments. The present study was undertaken to characterize the ENO gene family in sunflower in relation to seed development and lipid reserve accumulation.
Acknowledgements This work was supported by the “Ministerio de Economía y Competitividad” and FEDER (AGL2014-53537-R). JR is supported by a Discovery Grant (RGPIN 227271) from the National Science and Engineering Research Council of Canada. The authors would also like to thank the Hauts-de-France Region and the European Regional Development Fund (ERDF) 2014/2020 for the funding of this work.
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