Nitric Oxide and Frataxin: Two Players Contributing to Keep Cellular Iron Homeostasis.

RAMÍREZ, LEONOR; ZABALETA, EDUARDO; LAMATTINA, LORENZO

ANNALS OF BOTANY

Oxford University Press

Año: 2009

0305-7364

• Background: Nitric oxide (NO) is a signaling and physiologically active molecule in animals, plants and bacteria. The specificity of molecular mechanism/s involved in transducing the NO signal within and between cells and tissues is still poorly understood. NO has been shown to be an emerging and potent signal molecule in plant growth, development and stress physiology. The NO donor S-nitrosoglutathion (GSNO) was shown to be a biologically active compound in plants and a candidate for NO storage and/or mobilization between plant tissues and cells. NO has been implicated as a central component to maintain iron bioavailavility in plants. • Scope and Conclusions: Iron is an essential nutrient for almost all organisms. Here, we present an overview of the NO functions in iron metabolism in animals and discuss how NO production constitutes a key response in plant iron sensing and availability. In plants, NO drives downstream responses to both iron deficiency and iron overload. NO-mediated improvement of iron nutrition in plants growing under iron deficient conditions represents a powerful tool to cope with soils displaying low iron availability. An interconversion between different redox forms based on the iron and NO status of the plant cells might be the core of a metabolic process driving plant iron homeostasis. Frataxin, a recently identified protein in plants, plays an important role in mitochondria biogenesis and in maintaining mitochondrial iron homeostasis. We review and discuss the available evidence about the interaction between frataxin, NO and iron from the analysis of frataxin knock-down Arabidopsis thaliana mutants.