The soybean Dof-type transcription factor genes, GmDof4 and GmDof11, enhance lipid content in the seeds of transgenic Arabidopsis plants.
Soybean is one of the most important leguminous seed crops among the oil crops. Although the pathways for lipid biosynthesis have been identified, the factors that regulate the biosynthetic pathways at the transcriptional level are largely unknown. Here, we report our findings on the involvement of soybean Dof-type transcription factor genes in the regulation of the lipid content in soybean seeds. We identified 28 Dof-type transcription factor genes in soybean plants, and these genes displayed diverse patterns of expression in various organs. Seven flower/pod-specific genes and one constitutively expressed gene were further investigated. The proteins encoded by these seven genes were localized in the nucleus, and exhibited different abilities for transcriptional activation and DNA binding. Two genes, GmDof4 and GmDof11, were found to increase the content of total fatty acids and lipids in GmDof4 and GmDof11 transgenic Arabidopsis seeds. We also found that the 1000-seed weight was increased in the GmDof4 and GmDof11 transgenic plants. Using microarray and DNA binding analysis, we found that the two Dof-like proteins, GmDof4 and GmDof11, activated the acetyl CoA carboxylase gene and long-chain-acyl CoA synthetase gene, respectively, by direct binding to the cis-DNA elements in their promoter regions. In addition, both proteins downregulated the storage protein gene, CRA1, through direct binding. These results suggest that the two GmDof genes may augment the lipid content of soybean seeds by upregulating genes that are associated with the biosynthesis of fatty acids.
Wang
Hui-Wen
HW
National Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Zhang
Bo
B
Hao
Yu-Jun
YJ
Huang
Jian
J
Tian
Ai-Guo
AG
Liao
Yong
Y
Zhang
Jin-Song
JS
Chen
Shou-Yi
SY
D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D008055:Lipids / Q000032:analysis*; D020411:Oligonucleotide Array Sequence Analysis; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000235:genetics / Q000378:metabolism*; D013025:Glycine max / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D008055:Lipids; D010940:Plant Proteins; D014157:Transcription Factors