Auxin and Root Gravitropism: Addressing Basic Cellular Processes by Exploiting a Defined Growth Response

Root architecture and growth are decisive for crop performance and yield, and thus a highly topical research field in plant sciences. The root system of the model plant Arabidopsis thaliana is the ideal system to obtain insights into fundamental key parameters and molecular players involved in underlying regulatory circuits of root growth, particularly in responses to environmental stimuli. Root gravitropism, directional growth along the gravity, in particular represents a highly sensitive readout, suitable to study adjustments in polar auxin transport and to identify molecular determinants involved. This review strives to summarize and give an overview into the function of PIN-FORMED auxin transport proteins, emphasizing on their sorting and polarity control. As there already is an abundance of information, the focus lies in integrating this wealth of information on mechanisms and pathways. This overview of a highly dynamic and complex field highlights recent developments in understanding the role of auxin in higher plants. Specifically, it exemplifies, how analysis of a single, defined growth response contributes to our understanding of basic cellular processes in general.

Automated summary

Root architecture and growth play a crucial role in crop performance and yield, making it a highly relevant field of research in plant sciences. The root system of Arabidopsis thaliana serves as an ideal model for studying key parameters and molecular players involved in root growth responses to environmental stimuli. This review focuses on the function of PIN-FORMED auxin transport proteins, emphasizing their sorting and polarity control, and aims to integrate the wealth of information available on mechanisms and pathways to enhance understanding of auxin's role in higher plants.