Abstract
Plants have a mechanism for solubilization and uptake of iron to root cells. It is expected that the response of iron deficiency in roots are regulated by systemic long-distance signals and intracellular local signals. However, the long-distance signal itself is unknown, and it is not clear how these two signals affect iron uptake in roots. Therefore, we carried out the expression analysis in Arabidopsis using microarray.
The iron deficiency responsive genes were categorized by the strength of the influence of the long-distance signals or the local signals. The responsiveness to the long-distance signals or the local signals was correlated with categorization based on the Gene Ontology, indicating that there was qualitative difference between the two signals. Furthermore, we screened the genes responding to iron deficiency in both shoots and roots in order to find out the producer of the long-distance signals. Unexpectedly, only eight genes were induced in both shoots and roots, which included four bHLH type transcription factors and nicotianamine synthase. Our results suggest that nicotianamine possibly play a role in the long-distance signaling for iron uptake.
