Ectopic expression of EuWRI1, encoding a transcription factor in E. ulmoides, changes the seeds oil content in transgenic tobacco

The WRINKLED1 (WRI1) gene is a well‐established key transcriptional regulator involved in the regulation of fatty acid biosynthesis in developing seeds. In this study, a new WRI1 gene was isolated from seeds of Eucommia ulmoides and named EuWRI1. A close link between gibberellins signaling and EuWRI1 gene expression was suggested in this study. Functional characterization of EuWRI1 was elucidated through seed‐specific expression in tobacco. In transgenic tobacco, the expression of EuWRI1 in eight independent transgenic lines was detected by semiquantitative RT‐PCR. The relative mRNA accumulation of genes encoding enzymes involved in fatty acid biosynthesis (biotin carboxyl carrier protein and keto‐ACP synthase 1) was also assayed in tobacco seeds. Analysis of the seeds oil content and starch content indicated that the transgenic lines showed a significant increase in seeds oil content, whereas starch content decreased significantly. Further analysis of the fatty acid composition revealed that palmitic acid (16:0), linoleic acid (18:2) and linolenic acid (18:3) increased significantly in seeds of transgenic tobacco lines, but stearic acid (18:0) levels significantly declined. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:337–346, 2018