Transcriptomic Characterizations of the Molecular Mechanisms Regulating Lipid Production and Composition in Mortierella alpina in Response to Cold Stress

Abstract

Cold stress causes changes in the lipid composition of Mortierella alpina. In order to investigate the molecular mechanisms of M. alpina in response to cold stress, transcriptome analyses were performed on three groups of M. alpina cultured at (1) 25 °C, (2) 15 °C, and (3) first at 25 °C for 2 days and then 15 °C for 7 days, respectively. The results of a gas chromatography–mass spectrometry (GC–MS) analysis suggested that, compared with 25 °C conditions, dry weight and lipid production were significantly decreased in M. alpina grown at 15 °C, with a total of 1552 differentially expressed genes (DEGs) identified in response to cold stress. The quantitative real-time PCR (qRT-PCR) analysis was conducted to verify the expression patterns of six DEGs involved in lipid metabolism. Results of the enrichment analyses of the DEGs based on the Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases showed that fatty acid compositions were regulated by genes involved in the glycolysis pathway, fatty acid synthesis, the pentose phosphate pathway, the glycerolipid pathway, the tricarboxylic acid (TCA) cycle, and the glycerophospholipid pathway. Our study provided solid experimental evidence and novel insights into the metabolic engineering and the molecular mechanisms regulating the response to cold stress in M. alpina.

Advances in Molecular Exploration of Crop Plants under Environmental Stresses from Genetic and Genomic Perspectives

“…Varied levels of the highest biomass and lipid contents were obtained based on different laser irradiations and treatment durations, suggesting that laser mutagenesis could be a potentially effective method for generating economically important oleaginous microalgal strains. Conversely, Ren et al [21] performed transcriptomic analysis based on three experimental groups of M. alpina cultured under three different temperature conditions to investigate the molecular mechanisms underlying the molecular response to cold stress and the changes in the lipid composition of M. alpina. A total of 1552 DEGs were identified in the microalgae treated under cold stress and mainly involved in the metabolic pathways of glycolysis, fatty acid synthesis, pentose phosphate, glycerolipid, the tricarboxylic acid (TCA) cycle, and glycerophospholipid.…”