Project description:We wanted to understand at what level BTS acts, i.e. how upstream BTS acts and if BTS misregulation affets only a subset or multiple subsets of Fe regulated genes. We studied WT and bts-3 mutant roots. Using microarray analysis, we demonstrated that bts-3 has a consitutitive expression of Fe deficiency response in root.
Project description:E3 ligase BRUTUS (BTS), a putative iron sensor, is expressed in both root and shoot tissues in seedlings of Arabidopsis thaliana. The role of BTS in root tissues has been well established. However, its role in shoot tissues has been scarcely studied. Comparative transcriptome analysis with shoot and root tissues revealed that BTS is involved in regulating energy metabolism by modulating expression of mitochondrial and chloroplast genes in shoot tissues. Moreover, in shoot tissues of bts-1 plants, levels of ADP and ATP and the ratio of ADP/ATP were greatly increased with a concomitant decrease in levels of soluble sugar and starch. The decreased starch level inbts-1 shoot tissues was restored to the level of shoot tissues of wild-type plants upon vanadate treatment. Through this study, we expand the role of BTS to regulation of energy metabolism in the shoot in addition to its role of iron deficiency response in roots.