METHODS AND COMPOSITIONS FOR PRODUCING AND SELECTING TRANSGENIC PLANTS

摘要

Compositions and methods are provided for the production and selection of transgenic plants and plant parts, for increasing the transformation frequency of a plant or plant part, and for regulating the expression of a transgene, such as a herbicide tolerance polynucleotide. The methods and compositions allow for the delay in the expression of herbicide tolerance polynucleotides until a point in development during which herbicide selection is more efficient. Compositions comprise polynucleotide constructs comprising an excision cassette that separates a transgene, such as a herbicide tolerance polynucleotide, from its promoter and host cells comprising the same. The excision cassette comprises a polynucleotide encoding a site-specific recombinase operably linked to an inducible promoter and expression of the recombinase leads to excision of the excision cassette and expression of the transgene.

主权项

1. A polynucleotide construct comprising:
a) an excision cassette, comprising an expression cassette A (ECA) comprising:
i) a coding polynucleotide A (CPA) encoding a site specific recombinase; andii) an inducible promoter A (PA) operably linked to the CPA; b) a first and a second recombination site flanking the excision cassette; c) a coding polynucleotide B (CPB) encoding a herbicide tolerance polypeptide; and d) a promoter B (PB), wherein the PB is operably linked to the CPB after excision of the excision cassette.