Multilayer Networks Controlling Plant N-Acquisition

Nitrogen (N)–based fertilizers increase agricultural productivity but have detrimental effects on the environment and human health. Research is generating improved understanding of the signaling components plants use to sense N and regulate metabolism, physiology, growth and development. However, we still need to integrate these regulatory factors into signal transduction pathways and connect them to downstream response pathways. Using next generation sequencing, integrative network bioinformatics and systems biology approaches in Arabidopsis thaliana, we are dissecting regulatory networks acting at different levels of biological organization to control N-acquisition. At the molecular level, plants can adjust their capacity to acquire different forms of N in a range of concentrations by modulating the expression and function of genes in different N uptake systems. Modulation of plant growth and development, most notoriously changes in root system architecture, can also greatly impact plant N acquisition in soils. We will discuss our current bioinformatics and experimental efforts towards mapping gene networks leading to these adaptive responses for optimal N nutrition at the metabolic/physiological, developmental and organismal level. A holistic view of plant N nutrition should open avenues to translate this knowledge into effective strategies to improve N-use efficiency and enhance crop production systems for more sustainable agricultural practices.