Grafting-induced RNA mobility and Adaptive Functional Traits: Harnessing epigenetic inheritance for crop resilience to climate stress

Objetivo

Grafting, one of the oldest agricultural practices, can induce heritable epigenetic modifications by transmitting small RNAs (sRNAs) from rootstocks to scions. These mobile signals can reprogram the germline, opening possibilities for targeted epigenome changes by grafting. Harnessing this process could transform crop breeding by generating stable, heritable traits without genetic modification, thus sidestepping GMO restrictions. The project GRAFT will pioneer the systematic exploration of graft-induced heritable epigenetic modifications, using tomato both as a model system and globally important crop. Building on our unpublished discoveries that root-derived sRNAs induce epigenome changes in pollen, we will dissect the mechanisms, timing, and stability of graft-induced epigenetic changes. We aim to: (i) map the mobility of sRNAs between tissues and across species; (ii) determine whether graft-induced DNA methylation is transmitted to progeny; (iii) test the role of demethylation pathways in restricting inheritance; (iv) engineer rootstocks capable of inducing epigenetic marks in scions; and (v) explore whether stress-induced sRNAs in heterografts confer heritable stress tolerance. This project is groundbreaking because it establishes a mechanistic understanding for how grafting can be used to reprogram the plant germline, providing a roadmap for non-transgenic epigenetic breeding. It proposes a high-risk/high-gain strategy to exploit grafting as a non-transgenic breeding tool, expanding the breeder’s toolkit and offering a path to climate-resilient crops. If successful, it will establish a new principle: that rootstocks can be engineered to reprogram the germline of grafted plants, enabling durable, heritable improvements in stress resilience and yield stability. In addition to its scientific impact, this project will also provide world-class traininWe aim to elucidate the mechanism by which mobile siRNAs change traits and how to leverage this for crop improvement.