Plant & Animal Genomes XVII Conference Plant & Animal Genomes XVII ConferenceJanuary 10-14, 2009
Town & Country Convention Center
San Diego, CA
Clauber M P Bervald1 , Luciano C Maia1 , T Finatto1 , Emilia Malone1 , Camilo Vital2 , Adriana P S Bresolin1 , Maraisa Crestani1 , Simone N Wendt1 , Andrea M Almeida2 , Fernando I F Carvalho1 , Antonio Costa de Oliveira1
The mechanisms of tolerance to iron toxicity are extremely complex and many pieces of the puzzle remain to be placed. The understanding of this phenomenum at physiological and molecular levels will provide new insights to the problem, aiding the development of tolerant genotypes in rice breeding programs. In our group, strategies of mutant screening, mapping, in silico mining, expression arrays and qPCR are under development to assess the basis of iron uptake and homeostasis. The gene network responsible for iron toxicity responses involves many gene families, with variable number of copies, i.e. paralogous genes. The Nramp (Natural resistance associated macrophage proteins) constitute a highly conserved family of integral membrane proteins that are involved in metal ion transport in a wide range of organisms, including bacteria, fungi, plants, and animals. Promoter regions of different members can contain structural differences regarding the different activator elements of gene transcription (cis-acting) found in these regions, showing a complex genetic control for this character. Different Nramp loci in rice genome were investigated in order to assess the abundance and diversity of cis elements The results obtained showed the occurrence of 170 different cis-acting described in the PLACE portal. Among the eight OsNramp loci, the locus OsNramp 1 (96) presented the largest amount of different elements, followed by the loci OsNramp 7 (82) and OsNramp 3 (78). The frequency of distribution of elements in the rice genome and in other Oryza genomes as well as mutants showing unique patterns of iron metabolism are discussed.