Tomato Prosystemin Is Much More than a Simple Systemin Precursor
Donata Molisso,
Mariangela Coppola,
Martina Buonanno,
Ilaria Di Lelio,
Simona Maria Monti,
Chiara Melchiorre,
Angela Amoresano,
Giandomenico Corrado,
John Paul Delano-Frier,
Andrea Becchimanzi,
Francesco Pennacchio,
Rosa Rao
Affiliations
Donata Molisso
Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Naples, Italy
Mariangela Coppola
Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Naples, Italy
Martina Buonanno
Istituto di Biostrutture e Bioimmagini-CNR, Via Mezzocannone 16, 80134 Naples, Italy
Ilaria Di Lelio
Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Naples, Italy
Simona Maria Monti
Istituto di Biostrutture e Bioimmagini-CNR, Via Mezzocannone 16, 80134 Naples, Italy
Chiara Melchiorre
Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant’Angelo, Via Cinthia 4, 80126 Naples, Italy
Angela Amoresano
Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant’Angelo, Via Cinthia 4, 80126 Naples, Italy
Giandomenico Corrado
Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Naples, Italy
John Paul Delano-Frier
Center for Research and Advanced Studies (CINVESTAV) Irapuato, Department of Biochemistry and Biotechnology, Km. 9.6 Libramiento Norte Carretera Irapuato-León, Irapuato 36500, Mexico
Andrea Becchimanzi
Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Naples, Italy
Francesco Pennacchio
Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Naples, Italy
Rosa Rao
Department of Agricultural Sciences, University of Naples Federico II, Via Università 100, 80055 Naples, Italy
Systemin (Sys) is an octadecapeptide, which upon wounding, is released from the carboxy terminus of its precursor, Prosystemin (ProSys), to promote plant defenses. Recent findings on the disordered structure of ProSys prompted us to investigate a putative biological role of the whole precursor deprived of the Sys peptide. We produced transgenic tomato plants expressing a truncated ProSys gene in which the exon coding for Sys was removed and compared their defense response with that induced by the exogenous application of the recombinant truncated ProSys (ProSys(1-178), the Prosystemin sequence devoid of Sys region). By combining protein structure analyses, transcriptomic analysis, gene expression profiling and bioassays with different pests, we demonstrate that truncated ProSys promotes defense barriers in tomato plants through a hormone-independent defense pathway, likely associated with the production of oligogalacturonides (OGs). Both transgenic and plants treated with the recombinant protein showed the modulation of the expression of genes linked with defense responses and resulted in protection against the lepidopteran pest Spodoptera littoralis and the fungus Botrytis cinerea. Our results suggest that the overall function of the wild-type ProSys is more complex than previously shown, as it might activate at least two tomato defense pathways: the well-known Sys-dependent pathway connected with the induction of jasmonic acid biosynthesis and the successive activation of a set of defense-related genes, and the ProSys(1-178)-dependent pathway associated with OGs production leading to the OGs mediate plant immunity.