Far-red perception by vegetative organs and not fruits drives fruit growth responses in tomato plants

ABSTRACT: Responses to far-red are mediated by phytochromes, specialised photoreceptors present in all organs of a tomato plant. Although fruit-localised phytochromes can influence starch and sugar metabolism, their involvement in modulating fruit growth responses to far-red is unknown. We explored whether fruit growth responses to far-red are driven by local far-red perception within the fruits, or by a systemic response initiated in the vegetative organs. We applied far-red exclusively to the fruiting trusses, from anthesis to ripening, to the vegetative organs, to both, or to neither. We quantified plant development and fruit growth responses to far-red and carried out a transcriptomic analysis to establish the temporal dynamics of far-red perception and signalling in leaves and fruits. Supplementing far-red to the vegetative organs led to a significant increase in ripe fruit weight and sugar concentration, regardless of the light conditions experienced by the trusses, whereas far-red supplementation to the generative organs alone had no measurable effect. This study establishes that far-red perception by vegetative organs drives fruit growth responses in tomato. Local responses to far-red included a transient increase in auxin concentration and upregulation of the auxin-signalling pathway in leaves, a conserved response to decreasing R:FR ratios. In fruits, early transcriptomic responses carried signatures of auxin, cytokinin, and gibberellin biosynthesis and signalling, suggesting a role for hormones as mediators of far-red-induced fruit responses. Finally, this work reveals how responses to far-red perception by vegetative organs promote sink strength and starch biosynthesis in early developing fruits, contributing to higher fruit weight and sugar concentration in ripe fruits.

ORGANISM(S): Solanum lycopersicum

PROVIDER: GSE320482 | GEO | 2026/07/22

REPOSITORIES: GEO