Nucleic acid sequences encoding transcription factors regulating alkaloid biosynthesis and their use in modifying plant metabolism
View Patent ↗Plant metabolism and alkaloid levels can be regulated by transcription factors that regulate the nicotinic alkaloid biosynthetic pathway. In one embodiment, the disclosure provides a transcription factor that negatively regulates alkaloid biosynthesis, such as nicotine biosynthesis.
1. A method for increasing a nicotinic alkaloid in a Nicotiana plant, comprising up-regulating a transcription factor that positively regulates nicotinic alkaloid biosynthesis, wherein the transcription factor is up-regulated by:
(a) introducing into the Nicotiana plant an expression construct comprising a nucleic acid molecule selected from the group consisting of:
(i) the nucleotide sequence set forth in SEQ ID NO: 1 or SEQ ID NO: 2;
(ii) a nucleotide sequence that encodes a polypeptide having the amino acid sequence set forth in SEQ ID NO: 3; and
(iii) a nucleotide sequence that is at least 90% identical to the nucleotide sequences of (i) or (ii), and which encodes a transcription factor that positively regulates nicotinic alkaloid biosynthesis; and
(b) growing the Nicotiana plant under conditions whereby the expression construct increases levels of the transcription factor in the Nicotiana plant as compared to a control Nicotiana plant grown under similar conditions;
wherein the nucleic acid molecule is operably linked to one or more heterologous control sequences suitable for directing expression in a Nicotiana plant.
2. The method of claim 1 , further comprising overexpressing at least one additional transcription factor that positively regulates nicotinic alkaloid biosynthesis.
3. The method of claim 2 , further comprising suppressing the expression of at least one transcription factor that negatively regulates nicotinic alkaloid biosynthesis.
4. A genetically engineered nicotinic alkaloid-producing Nicotiana plant produced by the method of claim 2 , wherein the plant comprises a chimeric nucleic acid construct comprising a nucleic acid molecule encoded by a nucleotide sequence selected from the group consisting of:
(a) a nucleotide sequence set forth in SEQ ID NO: 1 or SEQ ID NO: 2;
(b) a nucleotide sequence that encodes a polypeptide having the amino acid sequence set forth in SEQ ID NO: 3; and
(c) a nucleotide sequence at least 90% identical to the nucleotide sequences of (a) or (b), and which encodes a transcription factor that positively regulates nicotinic alkaloid biosynthesis;
wherein the nucleic acid molecule is linked to a heterologous nucleic acid to form a chimeric nucleic acid construct.
5. The engineered Nicotiana plant of claim 4 , wherein the plant is a Nicotiana tabacum plant.
6. Seeds from the engineered Nicotiana plant of claim 4 , wherein the seeds comprise the chimeric nucleic acid construct.
7. A product comprising the engineered Nicotiana plant of claim 4 , wherein the product has an increased level of nicotinic alkaloid relative to a product produced from a non-transformed control Nicotiana plant.