Methods for high yield production of terpenes
Provided are enhanced high yield production systems for producing terpenes in plants via the expression of fusion proteins comprising various combinations of geranyl diphosphate synthase large and small subunits and limonene synthases. Also provided are engineered oilseed plants that accumulate monoterpene and sesquiterpene hydrocarbons in their seeds, as well as methods for producing such plants, providing a system for rapidly engineering oilseed crop production platforms for terpene-based biofuels.
1. A method of producing and accumulating a monoterpene hydrocarbon, a sesquiterpene hydrocarbon, or a combination thereof, in seeds of Camelina , the method comprising the steps of:
(a) transforming Camelina with a heterologous DNA construct, wherein said heterologous DNA construct comprises an enzyme-encoding nucleotide sequence encoding all, or a biosynthetically appropriate combination of, enzymes selected from the group consisting of a Mentha geranyl diphosphate synthase, a Mentha limonene synthase, an Arabidopsis farnesyl diphosphate synthase, and a Nicotiana 5-epi-aristolochene synthase, wherein said nucleotide sequence is operably linked for expression to a nucleotide sequence encoding Rubisco plastid transit peptide and to a promoter, wherein said promoter is an oleosin promoter, a napin promoter, or a glycinin promoter; and
(b) obtaining a transgenic Camelina plant comprising the DNA construct of step (a), wherein seeds of said transgenic Camelina plant accumulate the monoterpene hydrocarbon limonene, the sesquiterpene hydrocarbon 5-epi-aristolochene, or a combination thereof, wherein the amount of limonene, 5-epi-aristolochene, or combination thereof, is at least 1.0 mg/g dry weight.
2. The method of claim 1 , wherein the heterologous DNA construct further comprises a nucleotide sequence encoding an enzyme that catalyzes the biosynthesis of isopentenyl diphosphate and dimethylallyl diphosphate via the non-mevalonate pathway in plastids, wherein said nucleotide sequence further comprises a nucleotide sequence encoding RuBisCo small subunit transit peptide.
3. The method of claim 2 , wherein said enzyme encoding nucleotide sequence encodes a 1-deoxy-xylulose 5-phosphate synthase enzyme comprising RuBisCo small subunit transit peptide.
4. The method of claim 3 , further comprising expressing a nucleotide sequence encoding a selectable marker or a screenable marker that facilitates identification of transgenic seed, under the control of an operably linked promoter, wherein said promoter is an oleosin promoter, a napin promoter, or a glycinin promoter.
5. The method of claim 1 , further comprising recovering said monoterpene hydrocarbon limonene, said sesquiterpene hydrocarbon 5-epi-aristolochene, or combination thereof, from seeds of said transgenic Camelina plant.
6. The transgenic Camelina plant that produces and accumulates the monoterpene hydrocarbon limonene, the sesquiterpene hydrocarbon 5-epi-aristolochene, or a combination thereof, produced by the method of claim 1 .
7. A transgenic Camelina plant, cells of which comprise in their genome heterologous enzyme-encoding nucleotide sequences encoding all, or a biosynthetically appropriate combination of, enzymes selected from the group consisting of a Mentha geranyl diphosphate synthase, a Mentha limonene synthase, an Arabidopsis farnesyl diphosphate synthase, and a Nicotiana 5-epi-aristolochene synthase,
wherein each of said nucleotide sequences is operably linked for expression to a nucleotide sequence encoding Rubisco plastid transit peptide and to a promoter, wherein said promoter is an oleosin promoter, a napin promoter, or a glycinin promoter,
wherein said nucleotide sequences are coexpressed, and
wherein said transgenic Camelina plant accumulates the monoterpene hydrocarbon limonene, the sesquiterpene hydrocarbon 5-epi-aristolochene, or a combination thereof, in seeds thereof in an amount of at least 1.0 mg/g dry weight.
8. The transgenic Camelina plant of claim 7 , which further coexpresses a nucleotide sequence encoding an enzyme that catalyzes the biosynthesis of isopentenyl diphosphate and dimethylallyl diphosphate via the non-mevalonate pathway in plastids, wherein said nucleotide sequence comprises a nucleotide sequence encoding RuBisCo small subunit transit peptide.
9. The transgenic Camelina plant of claim 8 , wherein said enzyme encoding nucleotide sequence encodes a 1-deoxy-xylulose 5-phosphate synthase enzyme comprising RuBisCo small subunit transit peptide.
10. The transgenic Camelina plant of claim 9 , further comprising a nucleotide sequence encoding a selectable marker or a screenable marker that facilitates identification of transgenic seed, under the control of an operably linked promoter, wherein said promoter is an oleosin promoter, a napin promoter, or a glycinin promoter.