Characterization of factors regulating the end of flowering in solanum lycopersicum

• Autores: María Jesús López Martín
• Directores de la Tesis: Cristina Ferrandiz Maestre (dir. tes.), María Concepción Gómez Mena (dir. tes.), María del Pilar López Gresa (tut. tes.)
• Lectura: En la Universitat Politècnica de València ( España ) en 2025
• Idioma: inglés
• Tribunal Calificador de la Tesis: Salomé Prat (presid.), José María Jiménez Gómez (secret.), María Manuela Ribeiro Costa (voc.)
• Programa de doctorado: Programa de Doctorado en Biotecnología por la Universitat Politècnica de València
• Materias:
  • Ciencias de la vida
    • Biología vegetal (botánica)
      • Desarrollo vegetal
      • Fisiología vegetal
• Enlaces
  • Tesis en acceso abierto en: RiuNet
• Resumen

  • Flowering plants adjust their reproductive period to ensure reproductive success. This involves a tight control of flower initiation but also of the termination of the flowering period to optimize resource allocation for seed production. The end of flowering is marked by the cessation of the production of new flowers by the inflorescence meristems, that enter a dormant-like state known as proliferative arrest. This process has been mainly studied in Arabidopsis at the physiological, genetic and molecular levels, but remains to be characterized in other species to propose general mechanisms and provide the grounds to design biotechnological strategies aimed to control the duration of the fruit/seed productive season. Solanum lycopersicum (tomato) is an excellent model for this goal because of its economic importance but also the marked differences in plant architecture, meristem organization and fruit development. By comparing plants producing fertile and parthenocarpic seedless fruits, we have determined that proliferative arrest in tomato is a reversible process triggered by seed formation. We have identified the seeds as the likely source of signals that instruct the meristems to arrest in a coordinated and quantitative manner. The presence of auxin and abscisic acid in exudates from fertile but not from parthenocarpic fruits, and the effect on proliferative arrest of exogenous treatments with auxin on seedless fruits supports a major role of these phytohormones in the communication between seeds and meristems. On the other hand, we have studied the conservation of the FUL-AP2 pathway that controls the end of flowering in Arabidopsis thaliana. We developed molecular tools to modulate the expression of a FUL homolog in tomato (MBP20) and the sly-miR172, a negative regulator of AP2. By modulating these factors, we have obtained plants that show an early proliferative arrest in tomato. Our results indicate that the AP2-miR172 module is conserved between species, whereas the MBP20 gene seems to have an opposite role, promoting meristem activity in this species. Our work supports the conservation of factors controlling proliferative arrest in flowering plants, while providing new insights into the regulation of the process.