Caracterización de plantas de Arabidopsis thaliana sobreexpresantes de AtFH

TERENZI, A.; BUSI, M. V.; DIEGO FABIAN GOMEZ CASATI

Rosario

Congreso; XIX Congreso y XXXVII Reunión de la Sociedad de Biología de Rosario; 2017

Sociedad de Biologia de Rosario

Iron-sulfur (Fe-S) clusters are protein cofactors that play a major role in basic cellularprocesses, including respiration, photosynthesis and nitrogen fixation. There are threepathways for the assembly of these clusters in Arabidopsis thaliana: the SUF (sulfurmobilization) pathway, located in chloroplasts, the CIA (cytosolic Fe?S clusterassembly) pathway in the cytosol and the ISC (Fe?S cluster) assembly pathway inmitochondria. The Fe-S cluster assembly process can be divided into two steps: (i) Thecombination of S and Fe on a scaffold protein, and (ii) the transfer of the Fe-S cluster toa target protein. The transfer process requires several chaperones and carrier proteinswith specialized functions.It has been shown that Frataxin (FH) mediates the delivery ofFe2+ to the scaffold protein Isu for the assembly of the Fe-S clusters. The deficiency offrataxin caused progressive mitochondrial iron accumulation, severe disruption of Fe-Sbiosynthesis and increased oxidative stress. Frataxin deficient plants showed retardedgrowth, reduced fresh weight of fruits and reduced number of seeds per fruit. In thiswork, we generated transgenic Arabidopsis thaliana plants that overexpress AtFH.These plants present increased rosette area and longer primary and secondary roots.Results show that the overexpression of AtFH doesn?t modify the expression of genescoding for enzymes of the Fe-S cluster pathway although an increment in total ironcontent in some tissues was observed. Furthermore, the expression of genes involved inheme metabolism is altered. These results indicate that frataxin is an essential protein inplants, required for the biosynthesis of mitochondrial Fe-S proteins and heme groups.