Production of oil in vegetative tissues
The present invention relates to compositions and methods for providing RNA interference (RNAi) vectors comprising trigalactosyldiacylglycerol (tgd) biosynthesis enzyme constructs for increasing oil content of plants. Further, the use of tgd RNAi silencing vectors in combination with co-expression of heterologous oil regulating transcription factors, such as WRINKLED1, are contemplated to overcome the reduced growth and variable levels of embryonic lethality in plants with reduced TGD protein. Additionally, plants having reduced APS1, a gene encoding a major catalytic isoform of the small subunit of AGPase (AGP(−) plants), co-expressing a heterologous oil modulating transcription factor are contemplated for use in combination with plants having reduced TGD. Oil harvested from vegetative tissues of plants comprising vectors and genes of the present invention is contemplated for use in biofuel and biodiesel products.
1. A double gene vector construct, comprising two expression cassettes:
a first gene RNAi silencing expression cassette comprising a first constitutive promoter in operable combination with a nucleic acid segment comprising:
a first trigalactosyldiacylglycerol 3 (tgd3) fragment in its sense orientation with at least 95% sequence identity to a segment of SEQ ID NO: 14, 20 or 55, and
a second tgd3 fragment in antisense orientation relative to the first tqd3 fragment; and
a second gene expression cassette comprising a nucleic acid encoding a WRINKLED 1 transcription factor in operable combination with a second promoter.
2. The construct of claim 1 , wherein said first trigalactosyldiacylglycerol 3 (tgd3) fragment in its sense orientation has SEQ ID NO: 14.
3. The construct of claim 1 , wherein said second trigalactosyldiacylglycerol 3 (tgd3) fragment in its antisense orientation has SEQ ID NO: 52.
4. The construct of claim 1 , further comprising a spacer nucleic acid sequence located in between said sense fragment and said antisense fragment.
5. The construct of claim 1 , wherein said RNAi silencing expression cassette comprises SEQ ID NO: 20.
6. The construct of claim 1 , wherein said WRINKLED1 nucleic acid has a sequence that comprises at least 95% sequence identity to SEQ ID NO: 37 or 44.
7. The construct of claim 1 , wherein said second promoter is selected from the group consisting of a 35S cauliflower mosaic virus promoter and an Oleosin (OLE) promoter.
8. A reproductively competent plant comprising said construct of claim 1 , wherein said plant has accumulated lipid in its vegetative tissues.
9. The construct of claim 1 , wherein said WRINKLED1 nucleic acid encodes a WRINKLED1 protein encoded by a nucleic acid with at least 95% sequence identity to SEQ ID NO: 37 or 44.
10. The plant of claim 8 , wherein said plant is an oleaginous plant.
11. The plant of claim 8 , wherein said plant is selected from the group consisting of rice plants, beet plants, grape plants, Arabidopsis sp. plants, Brassica sp. plants, Brassica napus plants, grass plants and algae plants.
12. A plant seed comprising said construct of claim 1 .