Toughbranching: Discovering how root branching is affected in compacted soil

Descrizione del progetto

Radici resistenti: come affrontare lo stress meccanico del suolo

La compattazione del suolo è una sfida significativa per l’agricoltura, poiché ostacola la crescita delle radici e impedisce alle piante di assorbire l’acqua e le sostanze nutritive indispensabili per il loro sviluppo. Con il sostegno del programma di azioni Marie Skłodowska-Curie, il progetto Toughbranching si propone di studiare i segnali genetici e ormonali complessi come l’etilene e l’auxina, che regolano la ramificazione delle radici quando queste incontrano un terreno duro e compatto. Grazie all’uso di tecniche avanzate di imaging a raggi X e di trascrittomica spaziale, il progetto individuerà i geni specifici che consentono alle radici di adattarsi allo stress meccanico. Gli obiettivi aggiuntivi includono l’approfondimento delle conoscenze sulla plasticità della ramificazione delle radici, con l’obiettivo finale di contribuire a migliorare le strategie di selezione delle colture. Questi progressi sono fondamentali per lo sviluppo di piante resistenti, in grado di prosperare in condizioni pedologiche difficili.

Obiettivo

Soil compaction is a major constraint on root growth, reducing lateral root branching and limiting plant access to water and nutrients. While the physical effects of compaction are well documented, the hormonal and genetic mechanisms underlying root responses—particularly lateral root branching—remain largely unexplored. Auxin is a central regulator of lateral root development, but how auxin signaling interacts with mechanical stress to influence branching is not well understood. To address this, I will use state-of-the-art high-resolution X-ray computed tomography (X-ray CT) to examine how lateral root branching is altered as roots grow across compacted soil zones. This approach mimics natural field conditions, where roots encounter heterogeneous soil with randomly present compacted and non-compacted regions.
The host lab has made groundbreaking discoveries showing that ethylene accumulation in compacted soil triggers a cascade of signaling events that modulate ABA and auxin signaling to reshape root growth. Recently, the lab published a single-cell transcriptomic analysis of rice roots grown in compacted and non-compacted soils in Nature journal, identifying key auxin signaling genes induced by soil compaction in the pericyle cells from where lateral root development initiates. Building on these findings, I will investigate whether these genes are also involved in regulating lateral root branching under soil compaction. To uncover cell-specific gene expression changes associated with this process, I will apply spatial transcriptomics, enabling the identification of novel genes and pathways that control lateral root development under mechanical stress. This integrated approach will advance our understanding of root branching plasticity in response to soil compaction and contribute to strategies for breeding crops with improved resilience to challenging soil conditions.