Dissecting brassinosteroid signaling mediated regulation of root growth angle in wheat

RGA of different root-types (primary, seminal and crown) are often distinct to limit competition and are referred to as gravitropic setpoint angle (GSA). The vertical GSA of primary roots is maintained by the positive gravitropic mechanism, while non-vertical GSA in other root-types is determined by competing gravitropic and anti-gravitropic offset (AGO) mechanisms. Although past research in the model plant Arabidopsis unraveled gravitropic mechanisms, understanding of AGO mechanisms remains limited as crucial root-types (seminal and crown) do not exist in Arabidopsis. Moreover, these mechanisms remain largely unexplored in crops due to limited genetic resources.
Wheat, an important crop for the UK and world, represents an ideal system for studying RGA as all root-types are easily distinguiishable and have available genetic and genomic resources. Recently, we screened various wheat phytohormone signaling mutants (auxin, ethylene, brassinosteroid and bibberellin) for RGA and observed that BR signaling mutants (prominently for tabri1) show significantly steeper seminal and crown roots compared to wildtype.
Aim:
In this project, we will determine the molecular mechanisms by which brassinosteroids control RGA in wheat.
Output:
Improved understanding of molecular mechanisms controlling RGA will guide selection of alleles that can be exploited through DFW breeders toolkit.