Nitric Oxide and Frataxin: Two players contributing to plant iron homeostasis

RAMIREZ, L.; EDUARDO JULIAN ZABALETA; LAMATTINA, L.

ANNALS OF BOTANY

OXFORD UNIV PRESS

Año: 2010 vol. 105 p. 801 - 810

0305-7364

Background: Nitric oxide (NO) is a signaling and physiologically active molecule in3 animals, plants and bacteria. The specificity of molecular mechanism/s involved in4 transducing the NO signal within and between cells and tissues is/are still poorly5 understood. NO has been shown to be an emerging and potent signal molecule in plant6 growt, development and stress physiology. The NO donor S-nitrosoglutathion (GSNO)7 was shown to be a biologically active compound in plants and a candidate for NO storage8 and/or mobilization between plant tissues and cells. NO has been implicated as a central9 component to maintain iron bioavailavility in plants.10 • Scope and Conclusions: Iron is an essential nutrient for almost all organisms. Here, we11 present an overview of the NO functions in iron metabolism in animals and discus how12 NO production constitutes a key response in plant iron sensing and availability. In plants,13 NO drives downstream responses to both iron deficiency- and iron overload. NO14mediated improvement of iron nutrition in plants growing under iron deficient conditions15 represents a powerful tool to cope with soils displaying low iron availability. An16 interconversion between different redox forms based on the iron and NO status of the17 plant cells might be the core of a metabolic process driving the balance of plant iron18 homeostasis. Frataxin, a recently identified protein in plants, plays an important role in19 mitochondria biogenesis and in maintaining mitochondrial iron homeostasis. We review20 and discuss the available evidence abouts the interaction between frataxin, NO and iron21 from the analysis of frataxin know-down Arabidopsis thaliana mutants.