Responsable: José María Romero Rodríguez
Tipo de Proyecto/Ayuda: Plan Nacional del 2008
Referencia: BIO2008-02292
Fecha de Inicio: 01-01-2009
Fecha de Finalización: 31-12-2011

Empresa/Organismo financiador/es:

• Ministerio de Ciencia e Innovación

Equipo:

• Otros Investigadores:
  • Beatriz Castrillo Jiménez
  • Cristóbal Girón Gutiérrez
  • Marina Ribeiro Pedro
  • Teresa Ruiz Pérez

Contratados:

• Investigadores:
  • Tomás Albi Rodríguez
• Técnicos/Personal Administrativo:
  • Raquel González Palma
  • Isabel María Jiménez Benítez
  • María Tamara Jiménez Benítez

Resumen del proyecto:

Starch is the main carbon reserve in higher plants. The interest of this glucose polymer is due to its high production, wide distribution, and for being basic for nutrition and industry. ADP-Glucose Pyrophosphorylase (ADPGPPase) catalyzes the first and regulated step in starch synthesis. In the present project we propose to determine the contribution of the different ADPGPPase isoforms to starch synthesis in Arabidopsis thaliana. Double and triple mutants of the genes encoding for ADPGPPase will be generated and characterized. It is of special interest to analyze the contribution of APL1 and APL2 isoforms to starch synthesis as we have recently demonstrated that this two large subunits have catalytic activity. It is also proposed, by expressing the different subunits in E. coli, to purify to homogeneity the different ADPGPPase isoforms, to study the interaction among them and obtain specific antibodies for each isoform.

Sucrose and other sugars regulate, among other processes, starch synthesis. Sucrose Phosphate Synthase (SPS) and Sucrose Phosphate Phosphatase (SPP), the key enzymes involved in sucrose synthesis, will be characterized. In the Arabidopsis genome, four isoforms for each of both enzymes are encoded. We will determine the expression pattern of the different genes encoding SPS and SPP and study the regulation at the transcriptional level exerted by light and the circadian clock, as well as the putative interaction among SPS and SPP.

It is also proposed to analyze the regulation by sugars of starch biosynthesis by identifying the factors involved in the sugar control of APL3 and APL4 transcription by using a proteomic approach.

Finally, the quantitative role of starch in gravitropism and plagiotropism will be studied and its correlation with auxin fluxes and changes in the actin citoskeleton induced by gravistimulation analyzed.