Scopoletin 8-hydroxylase-mediated fraxetin production is crucial for iron mobilization (Plant Physiol)

As iron is often limiting in the environment, plants use many strategies to support iron uptake, including secretion of small molecules such as coumarins that can help to mobilize iron from the soil. Tsai et al. examined the role of a gene involved in fraxetin (7,8-dihydroxy-6-methoxycoumarin) production on iron uptake in Arabidopsis. SH8 expression is induced by low iron and encodes scopoletin 8-hydroxylase which catalyzes the final step in fraxetin synthesis. Using a range of natural accessions grown on non-available iron media (navFE), the authors showed a significant correlation with fraxetin production and shoot iron content. (Summary by Mary Williams) Plant Physiol. 10.1104/pp.18.00178