E-GEOD-42642 - The Arabidopsis copper transport protein COPT2 and the responses under copper and iron deficiency
Released on 5 June 2013, last updated on 3 May 2014
Copper and iron are essential micronutrients for most living organisms because they participate as cofactors in biological processes including respiration, photosynthesis and oxidative stress protection. In many eukaryotic organisms, including yeast and mammals, copper and iron homeostases are highly interconnected; however such interdependence is not well established in higher plants. Here we propose that COPT2, a high-affinity copper transport protein, functions under copper and iron deficiencies in Arabidopsis thaliana. COPT2 is a plasma membrane protein that functions in copper acquisition and distribution. Characterization of the COPT2 expression pattern indicates a synergic response to copper and iron limitation in roots. We have characterized a knockout of COPT2, copt2-1, that leads to increased resistance to simultaneous copper and iron deficiencies, measured as reduced leaf chlorosis and improved maintenance of the photosynthetic apparatus. We propose that COPT2 expression could play a dual role under Fe deficiency. First, COPT2 participates in the attenuation of copper deficiency responses driven by iron limitation maybe aimed to minimize further iron consume. On the other hand, global expression analyses of copt2-1 mutants versus wild type Arabidopsis plants indicate that low phosphate responses are increased in copt2-1 plants. In this sense, COPT2 function under Fe deficiency counteracts low phosphate responses. These results open up new biotechnological approaches to fight iron deficiency in crops. Four biological replicates of Arabidopsis seedlings were generated for 2 genotypes, Col-0 and copt2-1 mutant; and 3 growth condictions; first one an iron(Fe) and copper(Cu) sufficient medium (+Fe + Cu), second one an Fe deficient and Cu sufficient medium (-Fe+Cu) and third one an Fe and Cu deficient medium (-Fe-Cu). For each growth one comparasion was made, copt2-1 mutant versus Col-0; in each comparasion four biological replicates were made, two replicas were labeled with Cy5 for the mutant sample and Cy3 for the Col-0 sample, while the other two replicas were reversed-labeled.
transcription profiling by array
Francisco Vera-Sirera <email@example.com>, Ana Perea-García, Antoni Garcia-Molina, Francisco Vera-Sirera, Lola Peñarrubia, Miguel A Pérez-Amador, Nuria Andrés-Colás, Sergi Puig
Arabidopsis Copper Transport Protein COPT2 Participates in the Cross Talk between Iron Deficiency Responses and Low-Phosphate Signaling. Perea-Garcï¿½a A, Garcia-Molina A, Andrï¿½s-Colï¿½s N, Vera-Sirera F, Pï¿½rez-Amador MA, Puig S, Peï¿½arrubia L. , Europe PMC 23487432