The present disclosure relates, according to some embodiments, to pathogen resistant citrus compositions, organisms, systems, and methods. For example, a composition may comprise a peptide (e.g., a defensin peptide) and/or a nucleic acid (e.g., a defensin nucleic acid). A pathogen resistant citrus plant may comprise, in some embodiments, a defensin peptide and/or an expressible nucleic acid encoding a defensin peptide.
