Coordinated homeostasis of essential mineral nutrients: a focus on iron.

Marc Hanikenne,Hatem Rouached,Steven Fanara,Sara M Esteves,Janneke Balk

doi:10.1093/jxb/eraa483

Abstract

In plants, iron (Fe) transport and homeostasis are highly regulated processes. Fe deficiency or excess dramatically limits plant and algal productivity. Interestingly, complex and unexpected interconnections between Fe and various macro- and micronutrient homeostatic networks, supposedly maintaining general ionic equilibrium and balanced nutrition, are currently being uncovered. Although these interactions have profound consequences for our understanding of Fe homeostasis and its regulation, their molecular bases and biological significance remain poorly understood. Here, we review recent knowledge gained on how Fe interacts with micronutrient (e.g. zinc, manganese) and macronutrient (e.g. sulfur, phosphate) homeostasis, and on how these interactions affect Fe uptake and trafficking. Finally, we highlight the importance of developing an improved model of how Fe signaling pathways are integrated into functional networks to control plant growth and development in response to fluctuating environments.

Highlights

Iron (Fe) is an essential element for all living organisms (Kobayashi and Nishizawa, 2012)
Plants and algae are an important source of Fe entry in the terrestrial and aquatic food web, respectively. It is abundant in the environment, Fe is poorly available to plants in soils (Marschner, 2012), and Fe deficiency is a major issue limiting crop productivity, as well as the quality of agricultural products
Research opened to the investigation of interactions between nutrient homeostatic networks at the molecular level, revealing (i) multiple ways of nutrient inter-dependency: an element may be required for the proper uptake of another, deficiency or excess of one element impacts positively or negatively the uptake another, elements share pathways or regulatory processes and (ii) hidden responses that are more than the addition of single stress responses (Bouain et al, 2019b)

Summary

Introduction

Iron (Fe) is an essential element for all living organisms (Kobayashi and Nishizawa, 2012). Research opened to the investigation of interactions between nutrient homeostatic networks at the molecular level, revealing (i) multiple ways of nutrient inter-dependency: an element may be required for the proper uptake of another, deficiency or excess of one element impacts positively or negatively the uptake another, elements share pathways (e.g. transporters or chelators with broad specificity) or regulatory processes and (ii) hidden responses that are more than the addition of single stress responses (Bouain et al, 2019b).

Results

Conclusion