Enhancement of extraplastidic oil synthesis in Chlamydomonas reinhardtii using a type‐2 diacylglycerol acyltransferase with a phosphorus starvation–inducible promoter

• DOI: 10.1111/pbi.12210
• Publication Date: 2014-06-09T11:32:43Z
• Authors: Masako Iwai; Keiko Ikeda; Mie Shimojima; Hiroyuki Ohta
• Keywords: Chlamydomonas reinhardtii; Acyltransferases

When cultivated under stress conditions, many plants and algae accumulate oil. The unicellular green microalga Chlamydomonas reinhardtii accumulates neutral lipids (triacylglycerols; TAGs) during nutrient conditions. Temporal changes in TAG levels nitrogen (N)- phosphorus (P)-starved cells were examined to compare the effects of depletion on accumulation C. reinhardtii. fatty acid composition substantially changed depending cultivation stage before starvation. Profiles also differed between N P Logarithmic-growth-phase diluted into fresh medium showed substantial with both deprivation. deprivation induced formation oil droplets concomitant breakdown thylakoid membranes. In contrast, cytosol maintaining As a consequence, limitation accumulated more per cell culture these To enhance deprivation, we constructed deprivation-dependent overexpressor type-2 diacylglycerol acyl-CoA acyltransferase (DGTT4) using sulphoquinovosyldiacylglycerol 2 (SQD2) promoter, which was up-regulated transformant strongly enhanced slight increase 18 : 1 content, is preferred substrate DGTT4. These results demonstrated starvation-inducible promoter.