Xerobranching · Xero-Branching: discovering how plant roots adapt to reduced water availability
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2022-03-01 → 2024-02-29
- EU contribution
- €212,934
- Participants
- 1
- Scheme
- MSCA-IF
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Results in brief
Xero-Branching: discovering how plant roots adapt to reduced water availability
Background: Root branching is a major root trait that determine resource foraging capacity. Recently, the host laboratory discovered that root branching is regulated by heterogenous distribution of soil moisture at finer spatial scales. Using X-ray Computed Tomography (CT), it was demonstrated that root branching is completely suppressed in zones of low water availability in soil (e.g. air-filled gap). This root adaptive response termed as ‘Xerobranching’ (XB) was found conserved across many crop species. Initial studies suggested that Xerobranching was dependent on ABA and auxin responses. However, how these hormone pathways regulate Xerobranching was unclear. Given the agronomic importance of water stress and root branching on crop performance, the project aimed to uncover the molecular mechanism(s) underpinning the Xerobranching response. Proposed objectives: 1. Do roots exhibit Xerobranching in response to ABA-dependent changes in SUMOylation? 2. Does ABA trigger SUMOylation of auxin response factors during Xerobranching? 3. Does Xerobranching response impacts crop performance? Conclusion of the action: The research work provided multiple genetic evidence supporting a role for ABA during Xerobranching. Moreover, a novel method of studying transient stress response was developed which helped to elucidate the molecular basis of Xerobranching. The research revealed how dynamic hormone fluxes enable roots to adapt to heterogeneous soil conditions (Mehra et al., 2022 Science). The study elegantly showed that the Xerobranching response is distinct from auxin-regulated lateral root hydropatterning (Mehra et al., 2023 Curr. Op. Pl. Biol.). The research revealed that Xerobranching is independent of SUMOylation/DeSUMOylation processes of the Auxin Response factors. The study also showed that Xerobranching response and mechanism is conserved across crop species including millets (such as Setaria). Thus, Xerobranching represents an adaptive root response to optimize resource foraging in heterogenous soil environments. Overall, the study has effectively achieved the goals outlined in the proposed objectives and uncovered a universal blueprint for water stress sensing in plant roots, offering invaluable insights into how plants adapt to water scarcity.
Data: CORDIS, © European Union
Project objective
Plant roots forage for key resources like water and nutrients which are often distributed heterogeneously in soil. Plants optimize foraging by employing adaptive responses to modify their root shape. The host laboratory recently discovered (using non-invasive X-ray microCT imaging) that root branching is tightly regulated by the availability of soil moisture. For example, roots growing through an air-filled space transiently repress root branching until re-entering moist soil. This new root adaptive response is termed Xerobranching. Initial studies reveal that Xerobranching is dependent on ABA and auxin responses. However, how these hormone pathways cross-talk to regulate Xerobranching is unclear. Xerobranching is induced by transient accumulation of ABA in root tip tissues following reduced water uptake. Transient water stress also increases levels of protein SUMOylation in plant roots. The host lab recently reported in the journal Science that the transcription factor ARF7 is a target for SUMOylation during transient water stress. I will examine whether Xerobranching requires the ABA-dependent post-translational modification of key lateral root regulator, AUXIN RESPONSE FACTOR 7 (ARF7). I will also investigate whether Xerobranching depends on specific components of the SUMOylation machinery in an ABA-dependent manner. Furthermore, I will explore the wider impact of Xerobranching on soil exploration and crop performance. The highly interdisciplinary project will allow me to master advanced molecular and imaging techniques. This experience will uniquely position me to study adaptive responses at the root-soil interface and exploit allelic variation in key loci to create new varieties of cereal crops with greater foraging abilities.
Original text from CORDIS.
Participants
- THE UNIVERSITY OF NOTTINGHAM · NottinghamCoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union