Abstract
Copper is one of essential trance metals for most of living organisms. Cu/Zn SODs (CSD1 and CSD2) are involved in scavenging of reactive oxygen species in cytosol and chloroplasts respectively and their expression is down-regulated under copper deficient conditions. Previously, we demonstrated that one of microRNA, miR398, was expressed under low copper conditions, and was involved in the degradation of CSD1 and CSD2 mRNA. In addition, iron superoxide dismutase (FeSOD) is expressed instead of Cu/ZnSODs and complements their function under copper deficient conditions. We also identified SPL7 as a transcription activator for miR398. Furthermore SPL7 activated the other genes involved in copper homeostasis in copper deficient conditions. We concluded that SPL7 is a master regulator for copper homeostasis in Arabidopsis. In this study, we identified the other candidates of SPL7 by microarray analysis and tried to entirely uncover an adaptation mechanism for copper deficiency in Arabidopsis.
