GSE113802
RNA-Seq of Chromochloris zofingiensis in response to nitrogen deprivation
Chromochloris zofingiensis, featured by the capability of simultaneously synthesizing triacylglycerol (TAG) and astaxanthin, is emerging as a leading candidate alga for production uses. In order to better understand the oleaginous mechanism of this alga, we conducted a multi-omics analysis by systematically integrating the time-resolved transcriptomes, lipidomes, and metabolomes in response to nitrogen deprivation. The data analysis unraveled the distinct mechanism of TAG accumulation, which involved the coordinated stimulation of multiple biological processes including supply of energy and reductants, carbon reallocation from protein and starch, 'pushing' and 'pulling' carbon to TAG synthesis. Unlike in the model alga Chlamydomonas, the de novo fatty acid synthesis in C. zofingiensis was promoted, together with the enhanced turnover of both glycolipids and phospholipids, supporting the drastic need of acyls for TAG assembly. Moreover, genome-wide analysis identified many key functional enzymes and transcription factors with engineering potential for TAG modulation. Two genes encoding glycerol-3-phosphate acyltransferase (GPAT), the first committed enzyme for TAG assembly, were found in the genome of C. zofingiensis; in vivo functional characterization revealed that the extrachloroplastic GPAT instead of the chloroplastic one plays a central role in TAG synthesis. These findings illuminate distinct mechanism of oleaginousness of C. zofingiensis and pave a way toward rational manipulation of this alga as an emerging model for trait improvements. Overall design: Whole-cell mRNA profiles of Chromochloris zofingiensis at 5 time points (0, 3, 6, 12, and 24 h) of nitrogen deprivation (ND), in triplicate