Abstract: The invention relates to methods and compositions for modifying a characteristic of a plant without modifying the plant's genome using one or more cells comprising one or more phytohormone genes and at least one polynucleotide of interest, which one or more phytohormone genes and the at least one polynucleotide of interest are expressed in the one or more cells.

Abstract: Disclosed herein are engineered antimicrobial peptides (e.g, HTH peptide or AAPs) and methods of using such peptides to treat pathogenic infections, such as HLB disease and X. fastidiosa, in plants, such as citrus plants and grape plants. The engineered antimicrobial peptides may be derived from amphipathic helical peptides. The engineered antimicrobial peptides disclosed herein may be formed by coupling two or more amphipathic helical peptides. An engineered antimicrobial peptide may include a first amphipathic helical peptide coupled with a second amphipathic helical peptide by a linker domain forming a helix-turn-helix scaffold formation. Such amphipathic helical peptides may be endogenous to a target host, such as a plant (e.g., a citrus plant or grape plant).

Abstract: Two small proteins with anti-bacterial activity are generated and called optimized thionin and optimized pro-thionin. Optimized pro-thionin contains a signal sequence for intracellular trafficking of the protein and is cleaved off to yield optimized thionin. Genetically altered plants and their progeny expressing a polynucleotide encoding optimized pro-thionin or optimized thionin resist diseases caused by bacteria.

Abstract: Expression vectors and expression cassettes containing a tissue specific 5? transcription regulatory element, optionally linked to a translation regulatory element, optionally linked to an intron transcription regulatory element, operably linked to a heterologous polynucleotide encoding a protein or RNA of interest are described. The 5? transcription regulatory elements control expression in root tissue cells, phloem tissue cells, or fruit and/or abscission zone tissue cells. These sequences are obtained from citrus plants. Methods of use of these expression vectors and expression cassettes are described, as well as genetically altered plants and parts thereof that contain these expression vectors and/or cassettes.

Abstract: Expression vectors and expression cassettes containing a tissue specific 5? transcription regulatory element, optionally linked to a translation regulatory element, optionally linked to an intron transcription regulatory element, operably linked to a heterologous polynucleotide encoding a protein or RNA of interest are described. The 5? transcription regulatory elements control expression in root tissue cells, phloem tissue cells, or fruit and/or abscission zone tissue cells. These sequences are obtained from citrus plants. Methods of use of these expression vectors and expression cassettes are described, as well as genetically altered plants and parts thereof that contain these expression vectors and/or cassettes.

Abstract: Two small proteins with anti-bacterial activity are generated and called optimized thionin and optimized pro-thionin. Optimized pro-thionin contains a signal sequence for intracellular trafficking of the protein and is cleaved off to yield optimized thionin. Genetically altered plants and their progeny expressing a polynucleotide encoding optimized pro-thionin or optimized thionin resist diseases caused by bacteria.

Abstract: The generation of a chimeric protein containing a first domain encoding either a pro-thionon or thionin, a second domain encoding D4E1 or pro-D4E1, and a third domain encoding a peptide linker located between the first domain and second domain is described. Either the first domain or the second domain is located at the amino terminal of the chimeric protein and the other domain (second domain or first domain, respectively) is located at the carboxyl terminal. The chimeric protein has antibacterial activity. Genetically altered plants and their progeny expressing a polynucleotide encoding the chimeric protein resist diseases caused by bacteria.

Abstract: The generation of a chimeric protein containing a first domain encoding either a pro-thionon or thionin, a second domain encoding D4E1 or pro-D4E1, and a third domain encoding a peptide linker located between the first domain and second domain is described. Either the first domain or the second domain is located at the amino terminal of the chimeric protein and the other domain (second domain or first domain, respectively) is located at the carboxyl terminal. The chimeric protein has antibacterial activity. Genetically altered plants and their progeny expressing a polynucleotide encoding the chimeric protein resist diseases caused by bacteria.