INTEC   05402
INSTITUTO DE DESARROLLO TECNOLOGICO PARA LA INDUSTRIA QUIMICA
Unidad Ejecutora - UE
artículos
Título:
Transcriptome analysis reveals the genetic foundation for the dynamics of starch and lipid production in Ettlia oleoabundans
Autor/es:
WANG, DONGMEI; HEINRICH, JOSUÉ MIGUEL; WIJFFELS, RENE H.; EGGINK, GERRIT; GONG, YANHAI; XU, JIAN; KLOK, ANNE J.; STURME, MARK H.J.
Revista:
algal research
Editorial:
Elsavier
Referencias:
Lugar: amsteram; Año: 2018 vol. 33 p. 142 - 155
ISSN:
2211-9264
Resumen:
The oleaginous microalga Neochloris oleoabundans accumulates both starch and lipids to high levels under stressconditions such as nitrogen starvation (N-). To steer biosynthesis towards starch or lipids only, it is important tounderstand the regulatory mechanisms involved. Here physiological and transcriptional changes under nitrogenstarvation were analysed in controlled flat-panel photobioreactors at both short and long time-scales. Starchaccumulation was transient and occurred rapidly within 24 hrs upon starvation, while lipid accumulation was gradualand reached a maximum after 4 days. The major fraction of accumulated lipids was composed of de novo synthesizedneutral lipids - triacylglycerides (TAG) - and was characterized by a decreased composition of the polyunsaturatedfatty acids (PUFAs) C18:3 and C16:3 and an increased composition of the mono-unsaturated (MUFAs) and saturated(SFAs) fatty acids C18:1/C16:1 and C18:0/C16:0, respectively. RNA-sequencing revealed that starch biosynthesis anddegradation genes show different expression dynamics from lipid biosynthesis ones. An immediate rapid increase instarch synthetic transcripts was followed by an increase in starch degrading transcripts and a decrease in the starchsynthetic ones. In contrast, increased gene expression for fatty acid and TAG synthesis was initiated later andoccurred more gradually. Expression of several fatty acid desaturase (FAD) genes was decreased upon starvation,which corresponds to the observed changes to higher levels of MUFAs and SFAs. Moreover, several homologs oftranscription regulators that were implicated in controlling starch and lipid metabolism in other microalgae showeddifferential gene expression and might be key regulators of starch and lipid metabolism in N. oleoabundans as well.Our data provide insights into the genetic foundation of starch and lipid metabolism in N. oleoabundans under nitrogenstarvation and should facilitate metabolic engineering towards tailored strains with desired storage compoundcomposition.