Table 5_Engineering and application of multiepitope recombinant proteins to enhance resistance to Botrytis cinerea in tomatoes: a new paradigm for creating plant immune activators.xlsx

Plant elicitors have emerged as key agents in effectively invoking immune responses across various plant species, gaining attention for their role in sustainable agricultural protection strategies. However, the economic utility of peptide elicitors such as flg22, flgII-28, and systemin is limited when considering broader agricultural applications. This study introduces a novel recombinant protein, SlRP5, which integrates five active epitopes—flg22, csp22, flgII-28, SIPIP1, and systemin—to activate immune responses and significantly enhance resistance to Botrytis cinerea in tomatoes (Solanum lycopersicum). SIRP5 significantly induced reactive oxygen species (ROS), MAPK activation, and callose deposition in tomato leaves during in vitro experiments. Transcriptomic analysis revealed that SlRP5 more effectively activated key immune-related pathways compared to traditional peptides, upregulating critical genes involved in calcium-binding proteins and phenylpropanoid biosynthesis. In further in vivo experiments, SlRP5 alleviated B. cinerea-induced membrane damage by reducing MDA and REC levels, while simultaneously enhancing the activities of antioxidant enzymes such as SOD, CAT, and POD, thereby mitigating the excess ROS generated by infection. Additionally, SlRP5 elicited significant immunological effects in tobacco and eggplant, characterized by ROS bursts and callose deposition. It amplified tobacco’s resistance to TMV and mitigated B. cinerea-induced damage in eggplant. These findings underscore the substantial potential of SlRP5 as a plant immune activator, integrating multiple immune-eliciting peptides, and offering a novel strategy for cultivating new biopesticides that can induce immune responses and heighten disease resistance in various crops.