Abstract: The invention relates to vectors comprising nucleic acid sequences encoding transcriptional repressor silencing element binding factor referred as “SEBF”, transformed vegetal host and plants comprising said vectors. The invention also relates to methods of altering resistance of a plant to pathogens with SEBF encoding nucleic acids.

Abstract: The present invention relates to plant transcriptional activators and mutants thereof. Furthermore, the present invention relates to uses of plant transcriptional activators and mutants thereof for increasing plant defence responses to pathogens. In particular, the present invention relates to a peptide which confers increased pathogen resistance upon a plant expressing said peptide, said peptide having a sequence selected from the group consisting of SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4 mutated at a position selected from the group consisting of Glu271, Trp272 and residues between and including Pro123 to Gly128, an ortholog thereof, a homolog thereof, a functionally active fragment thereof or a functionally active variant thereof.

Abstract: The present invention describes a method of expressing PCA interacting partners in plant material comprising: (A) transforming said material with: (1) a first construct coding for a first fusion product comprising (a) a first fragment of a first molecule whose fragments can exhibit a detectable activity when associated and (b) a first protein-protein interacting domain; and (2) a second construct coding for a second fusion product comprising (a) a second fragment of said first molecule and (b) a second protein-protein interacting domain that can bind (1)(b); (B) culturing said material under conditions allowing expression of said PCA interacting partners; and (C) detecting said activity.

Abstract: Protein Fragment Complementation Assays (PCA) are done in plant material using enzyme fragment constructs, for example, dihydrofolate reductase (DHFR) fragment constructs. Plant material is transformed with at least two different constructs that form different products capable of interacting to reconstitute enzymatic activity in the plant material. Detection of the activity can be done using a substrate for the enzyme in the culture medium which, when reacted with the enzyme, is converted to a detectable product. One embodiment uses a substrate that can be enzymatically converted to a detectable fluorescent product. An inducer such as rapamycin or salicylic acid can be added to the culture medium to increase the level of detectable product.

Abstract: The present application describes a plant gene regulatory element and the uses thereof. More particularly a silencing element for modulating plant responses to pathogens, auxin and ethylene is described. The invention also describes transcriptional repressors which specifically binds onto the silencing element of the invention. Nucleotide and amino acid sequences of a novel transcriptional repressor referred as “SEBF” are given.

Abstract: The present invention describes a method of expressing PCA interacting partners in plant material comprising: (A) transforming said material with: (1) a first construct coding for a first fusion product comprising (a) a first fragment of a first molecule whose fragments can exhibit a detectable activity when associated and (b) a first protein-protein interacting domain; and (2) a second construct coding for a second fusion product comprising (a) a second fragment of said first molecule and (b) a second protein-protein interacting domain that can bind (1)(b); (B) culturing said material under conditions allowing expression of said PCA interacting partners; and (C) detecting said activity.

Abstract: In accordance with the present invention, there is provided an isolated and purified DNA fragment comprising a DNA sequence encoding a plant decarboxylase. Preferably, the DNA sequence encodes a plant tryptophan decarboxylase, more preferably from Catharanthus roseus. A 1747 bp cDNA clone was isolated by antibody screening of a cDNA expression library produced from poly A.sup.+ RNA found in developing seedlings of C. roseus. The invention also includes DNA sequences encoding a plant tryptophan decarboxylase which are synthetically produced to correspond substantially to the isolated and purified DNA sequence encoding the same enzyme. The nucleotide sequence of the synthetic DNA sequence is determined on the basis of codon degeneracy.