Soybean GmMYB73 promotes lipid accumulation in transgenic plants
- Equal contributors
1 State Key Lab of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
2 State Key Lab of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
3 Institute of Soybean Research, Heilongjiang Provincial Academy of Agricultural Sciences, Harbin 150086, China
BMC Plant Biology 2014, 14:73 doi:10.1186/1471-2229-14-73Published: 24 March 2014
Soybean is one of the most important oil crops. The regulatory genes involved in oil accumulation are largely unclear. We initiated studies to identify genes that regulate this process.
One MYB-type gene GmMYB73 was found to display differential expression in soybean seeds of different developing stages by microarray analysis and was further investigated for its functions in lipid accumulation. GmMYB73 is a small protein with single MYB repeat and has similarity to CPC-like MYB proteins from Arabidopsis. GmMYB73 interacted with GL3 and EGL3, and then suppressed GL2, a negative regulator of oil accumulation. GmMYB73 overexpression enhanced lipid contents in both seeds and leaves of transgenic Arabidopsis plants. Seed length and thousand-seed weight were also promoted. GmMYB73 introduction into the Arabidopsis try cpc double mutant rescued the total lipids, seed size and thousand-seed weight. GmMYB73 also elevated lipid levels in seeds and leaves of transgenic Lotus, and in transgenic hairy roots of soybean plants. GmMYB73 promoted PLDα1 expression, whose promoter can be bound and inhibited by GL2. PLDα1 mutation reduced triacylglycerol levels mildly in seeds but significantly in leaves of Arabidopsis plants.
GmMYB73 may reduce GL2, and then release GL2-inhibited PLDα1 expression for lipid accumulation. Manipulation of GmMYB73 may potentially improve oil production in legume crop plants.