Modification of plants by a peptide-mediated spraying method

Abstract

Introduction of foreign DNA into plant genomes to create genetically engineered plants not only requires a lengthy testing period and high developmental costs but also is not well-accepted by the public due to safety concerns about its effects on human and animal health and the environment. We have developed methods to modify plant by using functional peptides, and here, we present a high-throughput nucleic acids delivery platform for plants using peptide nanocarriers applied to the leaf surface by spraying. The translocation of sub-micrometer-scale nucleic acid/peptide complexes upon spraying varied depending on the physicochemical characteristics of the peptides and was controlled by a stomata-dependent-uptake mechanism in plant cells. We observed efficient delivery of DNA molecules into plants using cell-penetrating peptide (CPP)-based foliar spraying. Moreover, using foliar spraying, we successfully performed gene silencing by introducing small interfering RNA molecules in plant nuclei via siRNA-CPP complexes and, more importantly, in chloroplasts via our CPP/chloroplast-targeting peptide-mediated delivery system. This technology enables effective nontransgenic engineering of economically important plant traits in agricultural systems.