METHODS AND COMPOSITIONS TO IMPROVE THE SPREAD OF CHEMICAL SIGNALS IN PLANTS

摘要

Compositions and methods are provided which employ a chemical-gene switch. The chemical-gene switch disclosed herein comprises at least three components. The first component comprises a polynucleotide encoding a chemically-regulated transcriptional repressor; the second component comprises a repressible promoter operably linked to a polynucleotide of interest, and the third component comprises a gene silencing construct operably linked to a second repressible promoter, wherein the gene silencing construct encodes a silencing element that decreases the level of mRNA encoding the chemically -regulated transcriptional repressor. Expression of the polynucleotide of interest and the silencing construct is controlled by providing the appropriate chemical ligand. Transient induction from the chemical ligand leads to the production of the silencing element, and the destruction of the mRNA encoding the chemically-regulated transcriptional repressor. The presence of the silencing element maintains a state of de¬ repression. In specific embodiments, the silencing elements are cell non-autonomous, the state of de-repression becomes more distributed throughout the plant beyond where the chemical ligand reaches.