Abstract
The flowering plant shoot apical meristem (SAM) acts as a stem cell pool from which all aerial organs develop, including agronomically important inflorescence structures such as the wheat spike. The size of the SAM is maintained by the CLAVATA signalling pathway, a negative feedback loop which balances stem cell proliferation with differentiation and organ initiation. The CLAVATA signalling pathway has been extensively studied in Arabidopsis, and to a lesser extent in the monocots rice and maize and this work has highlighted that despite originating in the last common ancestor of land plants, CLAVATA function has diverse effects in different species. Disruption to CLAVATA function in maize has been shown to cause yield increases due to meristem enlargement, and this has highlighted the potential of manipulating CLAVATA function in agriculture.This thesis explores the CLAVATA signalling pathway in wheat and shows the effect of CLAVATA disruption on wheat development and yield. Bioinformatic analyses identified wheat CLAVATA components and provided insight into CLAVATA gene family evolution within the wider Triticeae. Gene trees informed the selection of TaCLV1 and TaCRN as targets for loss of function mutant generation using both pre-established mutant lines and CRISPR/Cas9 gene editing technology. Phenotypic analysis of Taclv1 and Tacrn loss of function mutants showed that Taclv1 mutant spikes were significantly shorter and underwent spike emergence and anthesis quicker than wild type spikes. Overall, this work has provided key insights into wheat CLAVATA pathway function, further highlighting the diversity of CLAVATA function between individual species. It also demonstrates the importance of investigating CLAVATA function in wheat to understand how CLAVATA manipulation could be used to improve yield.
| Date of Award | 4 Feb 2025 |
|---|---|
| Original language | English |
| Awarding Institution |
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| Supervisor | Jill Harrison (Supervisor) & Keith J Edwards (Supervisor) |
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