Abstract: Described herein are materials, methods, and kits useful for Agrobacterium-mediated transformation of plant cells and plants. In particular, the present disclosure provides a novel strain of Agrobacterium and its disarmed variant. The present disclosure further provides methods and kits for transforming plant cells and plants utilizing the novel strains of Agrobacterium.

Abstract: A novel method is described for the screening of gene elements of interest using hairy roots of chimeric plants transformed with Agrobacterium rhizogenes.

Abstract: A novel method is described for the screening of gene elements of interest using hairy roots of chimeric plants transformed with Agrobacterium rhizogenes.

Abstract: A novel method is described for the screening of gene elements of interest using hairy roots of chimeric plants transformed with Agrobacterium rhizogenes.

Abstract: Described herein is a bacterial cell containing a recombinant bacteriophage defense mechanism. The defense mechanism comprises a bacteriophage promoter (e.g., a phage .phi.31 promoter; a T7 promoter) operatively associated with a heterologous DNA encoding a product lethal to the bacterial cell. The bacterial cell is susceptible to infection by a bacteriophage, and the promoter is activated upon the infection of said bacterial cell by that bacteriophage. Bacteria useful in carrying out the invention include both gram negative and gram positive bacteria (e.g., Lactococcus lactis; Escherichia coli); the heterologous DNA may encode an enzyme that degrades nucleic acid (e.g., the products of the LlaI restriction cassette; barnase). Recombinant DNAs useful for making the foregoing cells, cultures prepared from such cells, and fermentation methods carried out with such cells are also disclosed.

Abstract: Recombinant pathogen-resistant plants comprise transformed plant cells, with the transformed plant cells containing a heterologous DNA construct comprising an expression cassette. The construct comprises a promoter, a structural gene positioned downstream from the promoter, and a termination sequence such as the nos terminator positioned downstream from the structural gene. The promoter is one which is activated by a plant pathogen which attacks the plant, such as the RB7 nematode-responsive element. The structural gene encodes a product such as Barnase which is toxic to the plant cells.