PLANTID · Conserved develoPmentaL trAjectories chaNnelling laTeral root prImorDium morphogenesis

Conserved develoPmentaL trAjectories chaNnelling laTeral root prImorDium morphogenesis

One of the most pressing challenges of the 21st century is sustaining agricultural productivity in the face of mounting environmental stress. Root systems are central to this challenge, as they anchor plants in the soil and control the uptake of water and nutrients. Their spatial configuration, referred to as root system architecture, is a key determinant of a plant’s capacity to adapt to drought, nutrient limitation, and other stressors. A crucial driver of root system architecture plasticity is the formation of lateral roots. By branching from the main root axis, lateral roots dramatically expand the soil volume that plants can explore. While this process has been extensively studied at the cell and molecular levels in the model dicot plant Arabidopsis thaliana, little is known about its operation in cereals and legumes, despite their significant agricultural relevance. These groups of plants have distinct anatomies and cell wall compositions, which likely require different developmental strategies. A critical aspect of LR formation is spatial accommodation, the process by which a newly initiated lateral root primordium breaches several pre-existing cell layers to emerge. This process requires a tightly coordinated program of cell wall remodelling, balancing the softening of overlying tissues with the reinforcement of the emerging organ. In monocots, this process is further complicated by the presence of the exodermis, a reinforced outer cell layer whose role during organ formation is not yet clear. The overall objective of PLANTID is to identify conserved genetic programs and key cell wall regulators that control root branching in two evolutionarily and agriculturally important models: the wild grass Brachypodium distachyon and the cultivated legume white lupin (Lupinus albus). By linking single-cell transcriptomic data and spatial transcriptomic data with detailed maps of cell wall composition in both species, the project aims to uncover how these plants coordinate the balance between growth and resistance during organogenesis. The long-term pathway to impact lies in translating this knowledge into breeding strategies for crops with more efficient, resilient root systems. Such crops could maintain growth under drought or poor soils, directly contributing to EU goals for sustainable agriculture, food security, and climate resilience.

Data: CORDIS, © European Union