Anthocyanin biosynthesis in carrot plants
The present invention provides transgenic carrot plants comprising at least one heterologous DNA sequence encoding: (a) a promoter of a transcription factor gene; or (b) a transcription factor geneoperably linked to a promoter; wherein the heterologous DNA sequence increases the expression of at least one gene encoding a sinapic acid glucosyltransferase (USAGT). The transcription factor gene is preferably DcMYB90 (SEQ ID NO:1) or DcEGL1 (SEQ ID NO:2) or a sequence having at least 80% identity to the sequence of SEQ ID NO:1 or at least 80% identity to the sequence of SEQ ID NO:2, wherein the sequence encodes a transcription factor protein increasing the expression of sinapic acid glucosyltransferase (USAGT) having the sequence of SEQ ID NO:4.
1 . A transgenic carrot plant comprising:
a. at least one heterologous DNA sequence consisting of the transcription factor gene DcMYB90 (SEQ ID NO:1) operably linked to a heterologous promoter and at least one heterologous DNA sequence consisting of the transcription factor gene DcEGL1 (SEQ ID NO:2) operably linked to a heterologous promoter; or
b. at least one heterologous DNA sequence consisting of the transcription factor gene DcMYB90 having at least 95% identity to the sequence of SEQ ID NO: 1, and at least one heterologous DNA sequence consisting of the transcription factor gene DcEGL1, having at least 95% identity to the sequence of SEQ ID NO:2;
wherein the transcription factor gene DcMYB90 (SEQ ID NO. 1) encodes the transcription factor protein of SEQ ID NO. 5, and the transcription factor gene DcEGL1 (SEQ ID NO. 2) encodes the transcription factor protein of SEQ ID NO. 6, and wherein the co-expression of the proteins increases the expression of sinapic acid glucosyltransferase (USAGT) having the sequence of SEQ ID NO: 4.
2 . A DNA sequence consisting of:
(a) a first transcription factor gene DcMYB90 (SEQ ID NO:1) operably linked to a heterologous promoter, and a second transcription factor gene DcEGL1 (SEQ ID NO:2) operably linked to a heterologous promoter; or
(b) a first transcription factor gene having a sequence with at least 95% identity to the sequence of SEQ ID NO:1 operably lined to a heterologous promoter, and the second transcription factor gene have a sequence with at least 95% identity to the sequence of SEQ ID NO: 2, operably linked to a heterologous promoter;
wherein the first transcription factor gene DcMYB90 (SEQ ID NO. 1) encodes the transcription factor protein of SEQ ID NO. 5, and the transcription factor gene DcEGL1 (SEQ ID NO. 2) encodes the transcription factor protein of SEQ ID NO. 6, and wherein the co-expression of the proteins increases the expression of sinapic acid glucosyltransferase (USAGT) having the sequence of SEQ ID NO:4, and wherein the heterologous promoter achieves an increase in expression of more than 30% in comparison to the expression of the corresponding transcription factor under its natural promoter.
3 . The DNA sequence according to claim 2 , wherein the heterologous promoter is:
(a) the CaMV 35 S promoter comprising the sequence of SEQ ID NO:3; or
(b) a sequence having at least 99% identity to the sequence of SEQ ID NO: 3, which sequence achieves an expression of a coding sequence in a plant cell of at least 99% of the sequence of SEQ ID NO:3.
4 . A method of producing a carrot plant comprising transforming an orange carrot plant with:
a. (a) at least one DNA sequence consisting of the transcription factor gene DcMYB90 (SEQ ID NO:1) operably linked to a heterologous promoter and at least one heterologous DNA sequence consisting of the transcription factor gene DcEGL1 (SEQ ID NO:2) operably linked to a heterologous promoter; of
b. at least one DNA sequence having at least 95% identity to the sequence of SEQ ID NO:1, and at least one DNA sequence having at least 95% identity to the sequence of SEQ ID NO:2 operably linked to a heterologous promoter;
wherein the transcription factor gene DcMYB90 (SEQ ID NO:1) encodes the transcription factor protein of SEQ ID NO; 5, and the transcription factor gene DcEGL1 (SEQ ID NO:2) encodes the transcription factor protein of SEQ ID NO: 6, and wherein the co-expression of the proteins
wherein the heterologous DNA sequence increases the expression of sinapic acid glucosyltransferase (USAGT) having the sequence of SEQ ID NO:4.
5 . The method of claim 4 , wherein the heterologous promoter is:
(a) the CaMV 35 S promoter comprising the sequence of SEQ ID NO:3 or
(b) a sequence having at least 99% identity to the sequence of SEQ ID NO: 3, wherein the sequence achieves an expression of a coding sequence in a plant cell of at least 99% of the sequence of SEQ ID NO: 3.
6 . A method of preparing a composition comprising anthocyanins, the method comprising:
(a) the method of producing a carrot plant according to claim 4 ; and
(b) isolating the composition comprising anthocyanins from the taproot of the carrot plants, wherein the composition comprises cyanidin 3-xylosyl (sinapoylglucosyl)galactoside in a concentration of at least 30% of the total anthocyanin concentration.
7 . The carrot plant according to claim 1 , wherein the transgenic carrot plant is not Daucus carota subsp sativus var atrorubens.