Understanding how the chloroplasts contribute to wheat susceptibility to rust fungi

Minter, Francesca Jane (2023) Understanding how the chloroplasts contribute to wheat susceptibility to rust fungi. Doctoral thesis, University of East Anglia.

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Abstract

Wheat rust fungi of the Pucciniaceae family, including Puccinia striiformis f. sp. tritici (Pst), pose a significant and sustained threat to global wheat production. Previous research has shown that yield losses associated with wheat rust infection primarily result from a reduction in the photosynthetic capacity of the plant. Additionally, it is widely understood that the chloroplasts are a hub for the synthesis and release of a number of pro-defence molecules including reactive oxygen species, calcium ions and salicylic acid, making them important organelles for coordinating the immune response. However, the molecular details of how chloroplast processes are manipulated during wheat infection with rust fungi remain to be elucidated. The main objective of this project was to investigate the ways in which wheat chloroplast processes contribute to rust susceptibility. To this aim, RNA-sequencing was carried out prior to the onset of this project on Pst-infected wheat tissue over time, revealing that many nuclear genes encoding chloroplast-localised proteins (NGCPs) had expression patterns that correlate with resistance to Pst at later stages of infection. I then selected the chloroplast metallopeptidase of unknown function (TaCPEP), which followed this pattern of expression, for further analyses. We obtained disruption mutants from a tetraploid and hexaploid Targeted Induced Local Lesions In Genomes (TILLING) population and showed that TaCPEP disruption increases susceptibility to both Pst and Magnaporthe oryzae pathotype triticum and may reduce chlorophyll content and chloroplast size, but without affecting the rate of assimilation. This thesis provides insight into the ways in which chloroplastic processes are altered during wheat infection with Pst and how one gene specifically may play a key role in susceptibility.

Item Type:	Thesis (Doctoral)
Faculty \ School:	Faculty of Science > School of Biological Sciences
Depositing User:	Nicola Veasy
Date Deposited:	26 Jun 2024 14:16
Last Modified:	26 Jun 2024 14:16
URI:	https://ueaeprints.uea.ac.uk/id/eprint/95693
DOI:

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