Responsable: José María Romero Rodríguez
Tipo de Proyecto/Ayuda: Plan Nacional del 2011
Referencia: BIO2011-28847-C02-02
Fecha de Inicio: 01-01-2012
Fecha de Finalización: 31-03-2015

Empresa/Organismo financiador/es:

• Ministerio de Ciencia e Innovación

Equipo:

• Investigadores:
  • Teresa Ruiz Pérez

Contratados:

• Investigadores:
  • Tomás Albi Rodríguez
  • Eva Isabel Lucas Reina
  • María Isabel Ortiz Marchena
  • Fatima Ezzahra Said
• Técnicos/Personal Administrativo:
  • Isabel María Jiménez Benítez
  • María Tamara Jiménez Benítez

Resumen del proyecto:

Developmental processes in plants are controlled by external and internal signals that modulate the final shape, growth and reproductive behaviour of the adult plant. This plasticity is influenced mainly by light, temperature and the nutrient income. The photoperiod pathway to flowering connect several of these signals in order to produce the florigen, or mobile signal that from the photosynthetic tissues will reach the apical meristems to induce the reprogramming of the meristem from vegetative to reproductive, activating the ABC floral developmental program. The role of CONSTANS gene product in this process is crucial because it coordinates light and temperature inputs for the production of FT, the mobile florigen hormone produced in the vascular bundles that is transported through the phloem to the apical meristem, activating the rest of the floral integrators, and thus inducing flowering. This is probably one of the most important discoveries in plant biology in recent years. While this photoperiodic response is well characterised, the knowledge about the influence of the nutrient signalling to flowering, mainly sugars, is poor. In this project we will study the relationship between photoperiodic flowering and sugar metabolism, something which had been proposed early last century, but for which no explanation has been provided so far. Sugars are not only a source of energy and structural moieties to a plant but also constitute important developmental messengers that modulate plant growth in conjunction with other hormonal signals like gibberellins (GAs) or absicic acid (ABA).

 A combined approach to study the influence of sugars in development will be made employing state-of-the-art techniques in plant biochemistry and molecular biology. The group of Dr JM Romero, a specialist in starch metabolism, will study the effect of the internal sucrose and glucose accumulation in plant development. A dual approach will be used: Insertion mutants affected in key enzymes of starch metabolism will be characterised at the protein and metabolic level; and the effect of activating mutagenesis analysed to detect key factors involved in this signalling cascade. Employing a novel molecular biology experimental design, an internal metabolic switch between sucrose and glucose, the most influential signalling sugars, will be made and the effect on global gene expression studied. In a coordinated manner, the group of Dr F Valverde, specialist in the photoperiodic flowering pathway, will study the effect that the photoperiodic processes have in the mobilization of carbon resources in the plant. An innovative evolutionary approach comparing the photoperiod response in higher plants (Arabidopsis) and algal (Chlamydomonas) model species will be made. The molecular mechanisms that activate CONSTANS protein will be studied in both species by protein tagging and nuclei purification in order to isolate and describe protein partners in vivo, something that has never been done before. In this project, the latest technologies in proteomics and transcriptomics will be employed to analyse the effect of sugars in developmental processes in order to identify new genes of the nutrient pathway to flowering by purifying protein complexes and analysing mutant libraries produced in the group in previous projects.