The role of glutaredoxins in regulating root function and development in response to environmental changes

The many changes in environmental conditions mean that plants have a wide range of responses that enable them to adapt constantly. Among the molecular players involved, glutaredoxins (GRXs), small proteins associated with redox metabolism, have emerged in recent years as key elements. While classes I and II of this family of regulators are clearly associated with redox pathways, class III GRXs, which are specific to plants, appear to be involved in signaling pathways without clear redox activity. GRXs are central to a variety of responses to the environment, and their role in regulating root function and development has recently been the subject of numerous studies. Scope. The aim of this review is to describe the role of GRXs in the regulation of root function and development in response to the environment. After describing the biochemical functions of GRXs according to their class and their specific features in plants, we aim to illustrate how class II and III GRXs are involved in the mechanisms by which plants adapt to the environment, and in particular in the regulation of root traits. Although their involvement has been described in the response to multiple environmental variations, we also illustrate that many members of class III have a specific and critical role in root nitrate signaling. We conclude that GRXs are emerging as major players in the response to environmental variations. The development of a sub-family specific to plants, and their biochemical divergence, currently make them regulators of particular interest for understanding plant adaptation to climate constraints.