Regulación hormonal del desarrollo temprano del fruto en Arabidopsis thaliana.

El fruto es un órgano esencial para las plantas, dado que permite que las semillas se desarrollen y maduren correctamente, y que se dispersen una vez completada su maduración. Desde hace varias décadas se ha propuesto que el proceso de desarrollo del fruto está modulado por fitohormonas, fundamentalmente giberelinas y auxinas, y que las semillas en desarrollo impulsarían el crecimiento del fruto mediante la síntesis de estas hormonas en su interior. Los mecanismos molecularres que rigen la actuación de estas hormonas, sin embargo, no se conocen. En diversas especies se ha descrito desde los años 30 que auxinas y giberelinas pueden inducir desarrollo del fruto independientemente de la fertil…

Higher plants possess two different types of ATX1-like copper chaperones.

Abstract Copper (Cu) chaperones constitute a family of small Cu+-binding proteins required for Cu homeostasis in eukaryotes. The ATX1 family of Cu chaperones specifically delivers Cu to heavy metal P-type ATPases. The plant Arabidopsis thaliana expresses the ATX1-like Cu chaperone CCH, which exhibits a plant-specific carboxy-terminal domain (CTD) with unique structural properties. We show that CCH homologues from other higher plants contain CTDs with structural properties similar to Arabidopsis CCH. Furthermore, we identify a new ATX1-like Cu chaperone in Arabidopsis, AtATX1, which functionally complements yeast atx1Δ and sod1Δ associated phenotypes, and localizes to the cytosol of Arabidop…

Comparison of global responses to mild deficiency and excess copper levels in Arabidopsis seedlings

[EN] Copper is an essential micronutrient in higher plants, but it is toxic in excess. The fine adjustments required to fit copper nutritional demands for optimal growth are illustrated by the diverse, severe symptoms resulting from copper deficiency and excess. Here, a differential transcriptomic analysis was done between Arabidopsis thaliana plants suffering from mild copper deficiency and those with a slight copper excess. The effects on the genes encoding cuproproteins or copper homeostasis factors were included in a CuAt database, which was organised to collect additional information and connections to other databases. The categories overrepresented under copper deficiency and copper e…

GM foods in Spanish newspapers.

The Arabidopsis Copper Transporter COPT1 Functions in Root Elongation and Pollen Development

Copper plays a dual role in aerobic organisms, as both an essential and a potentially toxic element. To ensure copper availability while avoiding its toxic effects, organisms have developed complex homeostatic networks to control copper uptake, distribution, and utilization. In eukaryotes, including yeasts and mammals, high affinity copper uptake is mediated by the Ctr family of copper transporters. This work is the first report on the physiological function of copper transport in Arabidopsis thaliana. We have studied the expression pattern of COPT1 in transgenic plants expressing a reporter gene under the control of the COPT1 promoter. The reporter gene is highly expressed in embryos, tric…