LAUSR

Cotton is not only the most important fiber crop but also the fifth most important oilseed crop in the world because of its oil-rich seeds as a byproduct of fiber production. By comparative transcriptome analysis between two germplasms with diverse oil accumulation, we reveal pieces of the gene expression network involved in the process of oil synthesis in cottonseeds. Approximately 197.16 Gb of raw data from 30 RNA sequencing samples with three biological replicates were generated. Comparison of the high-oil and low-oil transcriptomes enabled the identification of 7,682 differentially expressed genes (DEGs). Based on gene expression profiles relevant to triacylglyceride (TAG) biosynthesis, we proposed that the Kennedy pathway (diacylglycerol acyltransferase (DGAT)-catalyzed diacylglyceride (DAG) to TAG) is the main pathway for oil production, rather than the phospholipid diacylglycerol acyltransferase (PDAT)-mediated pathway. Using weighted gene co-expression network analysis, 5,312 DEGs were obtained and classified into 14 co-expression modules, including the MEblack module containing 10 genes involved in lipid metabolism. Among the DEGs in the MEblack module, GhCYSD1 was identified as a potential key player in oil biosynthesis. The overexpression of GhCYSD1 in yeast resulted in increased oil content and altered fatty acid composition. This study may not only shed more light on the underlying molecular mechanism of oil accumulation in cottonseed oil, but also provide a set of new gene for potential enhancement of oil content in cottonseeds. This article is protected by copyright. All rights reserved.