Multiomics analysis reveals a distinct mechanism of oleaginousness in the emerging model alga Chromochloris zofingiensis. (1st April 2019)

• Record Type: Journal Article
• Authors: Liu, Jin; Sun, Zheng; Mao, Xuemei; Gerken, Henri; Wang, Xiaofei; Yang, Wenqiang
• Is Part Of: Plant journal. Volume 98:Number 6(2019)
• Page Start: 1060
• Page End: 1077
• Publication Date: 2019-04-01
• Subjects: Chromochloris zofingiensis -- glycerol‐3‐phosphate acyltransferase -- oleaginousness -- multiomics -- trait improvement -- triacylglycerol; Plant molecular biology -- Periodicals; Plant cells and tissues -- Periodicals; Botany -- Periodicals; 580
• DOI: 10.1111/tpj.14302
• Languages: English
• ISSNs: 0960-7412

Abstract

Summary: Chromochloris zofingiensis, featured due to its capability to simultaneously synthesize triacylglycerol (TAG) and astaxanthin, is emerging as a leading candidate alga for production uses. To better understand the oleaginous mechanism of this alga, we conducted a multiomics analysis by systematically integrating time‐resolved transcriptomes, lipidomes and metabolomes in response to nitrogen deprivation. The data analysis unraveled the distinct mechanism of TAG accumulation, which involved coordinated stimulation of multiple biological processes including supply of energy and reductants, carbon reallocation from protein and starch, and 'pushing' and 'pulling' carbon to TAG synthesis. Unlike the model alga Chlamydomonas, de novo fatty acid synthesis in C. zofingiensis was promoted, together with enhanced turnover of both glycolipids and phospholipids, supporting the drastic need of acyls for TAG assembly. Moreover, genomewide analysis identified many key functional enzymes and transcription factors that had engineering potential for TAG modulation. Two genes encoding glycerol‐3‐phosphate acyltransferase (GPAT), the first committed enzyme for TAG assembly, were found in the C. zofingiensis genome; in vivo functional characterization revealed that extrachloroplastic GPAT instead of chloroplastic GPAT played a central role in TAG synthesis. These findings illuminate distinct oleaginousness mechanisms in C. zofingiensis and pave the way towards rational manipulation of this alga to becone an emerging model for trait improvements. Significance Statement: A multiomics study using systematically integrating time‐resolved transcriptomes, lipidomes and metabolomes was conducted for the emerging model alga C. zofingiensis . The 'omics data analysis, plus in vivo functional characterization of glycerol‐3‐phosphate acyltransferases, uncovered distinct oleaginousness characteristics and provided insights into rational manipulation of this alga for trait improvements.