Phosphorus (P) is an essential macronutrient for the production of food crops and the demand for P fertilizer is increasing worldwide. Earth's P is being depleted at an alarming rate urging the need for alternative strategies in order to maximize the availability of agronomic resources, optimize crop yields and guarantee food security with less impact on our environment. White lupin is the only crop that can form specific organs constituted by numerous short lateral roots, the so-called cluster roots (CRs), as an adaptation to low P availability in the soil, allowing an efficient acquisition of this nutrient, which is fundamental for plant growth and development. Remarkable advances have been made over the last years in identifying numerous genes involved in different facets of root adaptation to the environment and is known that microRNAs play a pivotal role in regulating gene expression during development and in response to environmental cues. The main objective of LUMIROOT is to elucidate the miRNA-dependent mechanisms regulating the formation of CRs in white lupin contributing to optimize plant resource acquisition based on the already proven role of miRNAs in root developmental processes. I will focus on these networks based not only on their functional importance but also on the broader interest of regulatory pathways controlling the development CRs. I will in deep functionally analyze the role miR396/target genes modules in CR development and reveal novel miRNA regulatory networks acting in CR formation and function. I also aim to develop miRNA-based nanoparticles to modulate in vivo miR396 action, as well as other regulatory miRNA/target networks to assess its potential to improve relevant agronomic traits such as CRs formation. LUMIROOT project will allow opening the way to crop improvement reducing the need for P fertilizers and will help to select regulatory networks with potential use in the improvement of relevant agronomic traits.