Compositions and methods for altering flowering and plant architecture to improve yield potential

Abstract

The present invention provides recombinant DNA constructs, vectors and molecules comprising a polynucleotide sequence encoding a florigenic FT protein operably linked to a vegetative stage promoter, which may also be a meristem-preferred or meristem-specific promoter. Transgenic plants, plant cells and tissues, and plant parts are further provided comprising a polynucleotide sequence encoding a florigenic FT protein. Transgenic plants comprising a florigenic FT transgene may produce more bolls, siliques, fruits, nuts, or pods per node on the transgenic plant, particularly on the main stem of the plant, relative to a control or wild type plant. Methods are further provided for introducing a florigenic FT transgene into a plant, and planting transgenic FT plants in the field including at higher densities. Transgenic plants of the present invention may thus provide greater yield potential than wild type plants and may be planted at a higher density due to their altered plant architecture.

What is claimed is: 
     
         1 . A recombinant DNA construct comprising a polynucleotide sequence encoding a florigenic FT protein operably linked to a vegetative stage promoter. 
     
     
         2 . The recombinant DNA construct of  claim 1 , wherein the florigenic FT protein comprises an amino acid sequence having at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20, or a functional fragment thereof. 
     
     
         3 . The recombinant DNA construct of  claim 2 , wherein the florigenic FT protein further comprises one or more of the following amino acids: a tyrosine or other uncharged polar or nonpolar residue at the amino acid position of the florigenic FT protein corresponding to amino acid position 85 of SEQ ID NO: 14; a leucine or other nonpolar residue at the amino acid position of the florigenic FT protein corresponding to amino acid position 128 of SEQ ID NO: 14; and a tryptophan or other large nonpolar residue at the amino acid position of the florigenic FT protein corresponding to amino acid position 138 of SEQ ID NO: 14. 
     
     
         4 . The recombinant DNA construct of  claim 2 , wherein the florigenic FT protein does not have one or more of the following amino acids: a histidine at the amino acid position corresponding to a lysine or arginine at the amino acid position corresponding to position 85 of SEQ ID NO: 14; a lysine or arginine at the amino acid position corresponding to position 128 of SEQ ID NO: 14; and a serine, aspartic acid, glutamic acid, lysine or arginine at the amino acid position corresponding to position 138 of SEQ ID NO: 14. 
     
     
         5 . The recombinant DNA construct of  claim 2 , wherein the florigenic FT protein comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20, or a functional fragment thereof. 
     
     
         6 . The recombinant DNA construct of  claim 1 , wherein the polynucleotide sequence is at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identity to a sequence selected from the group consisting of SEQ ID NOs: 1, 3, 5, 7, 9, 11, 13, 15, 17, and 19. 
     
     
         7 . The recombinant DNA construct of  claim 1 , wherein the vegetative stage promoter is a meristem-preferred or meristem-specific promoter. 
     
     
         8 . The recombinant DNA construct of  claim 1 , wherein the promoter comprises a polynucleotide sequence that is at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or least 99% identical to a polynucleotide sequence selected from the group consisting of SEQ ID NOs: 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, or 35, or a functional portion thereof. 
     
     
         9 . The recombinant DNA construct of  claim 1 , wherein the promoter comprises the pAt.Erecta promoter of SEQ ID NO: 21, or a functional portion thereof 
     
     
         10 . The recombinant DNA construct of  claim 9 , wherein the promoter comprises the truncated pAt.Erecta promoter of SEQ ID NO: 22 or SEQ ID NO: 38. 
     
     
         11 . The recombinant DNA construct of  claim 1 , wherein the promoter comprises the pAt.Erl 1 promoter of SEQ ID NO: 34, or a functional portion thereof. 
     
     
         12 . A DNA molecule or vector comprising the recombinant DNA construct of  claim 1 . 
     
     
         13 . A plasmid vector for  Agrobacterium -mediated transformation comprising the recombinant DNA construct of  claim 1 . 
     
     
         14 . A donor template molecule for site-directed integration comprising the recombinant DNA construct of  claim 1 . 
     
     
         15 . A transgenic plant comprising an insertion of the recombinant DNA construct of  claim 1  into the genome of the transgenic plant. 
     
     
         16 . The transgenic plant of  claim 13 , wherein the transgenic plant is homozygous for the insertion of the recombinant DNA construct. 
     
     
         17 . The transgenic plant of  claim 15 , wherein the transgenic plant is hemizygous for the insertion of the recombinant DNA construct. 
     
     
         18 . The transgenic plant of  claim 15 , wherein the transgenic plant is a short day plant. 
     
     
         19 . The transgenic plant of  claim 15 , wherein the transgenic plant is a dicotyledonous plant. 
     
     
         20 . The transgenic plant of  claim 19 , wherein the transgenic plant is a leguminous plant. 
     
     
         21 . The transgenic plant of  claim 20 , wherein the transgenic plant is soybean. 
     
     
         22 . The transgenic plant of  claim 21 , wherein the transgenic soybean plant produces more pods per node than a control plant not having the recombinant DNA construct. 
     
     
         23 . The transgenic plant of  claim 15 , wherein the transgenic plant produces more flowers per node than a control plant not having the recombinant DNA construct. 
     
     
         24 . The transgenic plant or part thereof of  claim 15 , wherein the transgenic plant produces more bolls, siliques, fruits, nuts or pods per node of the transgenic plant than a control plant not having the recombinant DNA construct. 
     
     
         25 . The transgenic plant or part thereof of  claim 15 , wherein the transgenic plant flowers earlier than a control plant not having the recombinant DNA construct. 
     
     
         26 . The transgenic plant or part thereof of  claim 15 , wherein the transgenic plant has more floral racemes per node than a control plant not having the recombinant DNA construct. 
     
     
         27 . A transgenic plant part comprising the recombinant DNA construct of  claim 1 . 
     
     
         28 . The transgenic plant part of  claim 27 , wherein the transgenic plant part is one of the following: a seed, fruit, leaf, cotyledon, hypocotyl, meristem, embryo, endosperm, root, shoot, stem, pod, flower, infloresence, stalk, pedicel, style, stigma, receptacle, petal, sepal, pollen, anther, filament, ovary, ovule, pericarp, phloem, or vascular tissue. 
     
     
         29 . A method for producing a transgenic plant, comprising
 (a) transforming at least one cell of an explant with a recombinant DNA construct comprising a polynucleotide sequence encoding a florigenic FT protein operably linked to a vegetative stage promoter; and   (b) regenerating or developing the transgenic plant from the transformed explant.   
     
     
         30 . The method of  claim 29 , wherein the vegetative stage promoter of the recombinant DNA construct is a meristem-preferred or meristem-specific promoter. 
     
     
         31 . The method of  claim 29 , further comprising:
 (c) selecting a transgenic plant having one or more of the following traits or phenotypes: earlier flowering, longer reproductive or flowering duration, increased number of flowers per node, increased number of floral racemes per node, increased number of pods, bolls, siliques, fruits, or nuts per node, and increased number of seeds per node, as compared to a control plant not having the recombinant DNA construct.   
     
     
         32 . The method of  claim 29 , wherein the transforming step (a) is carried out via  Agrobacterium -mediated transformation or microprojectile bombardment of the explant. 
     
     
         33 . The method of  claim 29 , wherein the transforming step (a) comprises site-directed integration of the recombinant DNA construct. 
     
     
         34 . A method of planting a transgenic crop plant, comprising:
 planting the transgenic crop plant at a higher density in the field, wherein the transgenic crop plant is transformed with a recombinant DNA construct comprising a polynucleotide sequence encoding a florigenic FT protein operably linked to a vegetative stage promoter.   
     
     
         35 . The method of  claim 34 , wherein the vegetative stage promoter is a meristem-preferred or meristem-specific promoter. 
     
     
         36 . The method of  claim 34 , wherein the transgenic crop plant is soybean, and wherein about 150,000 to 250,000 seeds of the transgenic soybean plant are planted per acre. 
     
     
         37 . The method of  claim 34 , wherein the transgenic crop plant is cotton, and wherein about 48,000 to 60,000 seeds of the transgenic cotton plant are planted per acre. 
     
     
         38 . The method of  claim 34 , wherein the transgenic crop plant is canola, and wherein about 450,000 to 680,000 seeds of the transgenic canola plant are planted per acre.