| This project going to be… | Experimental (lab/field based) |
| Email | jc913@cam.ac.uk |
| Position held | Principal Investigator |
| Title of Project | Effect of defense hormones, Jasmonic Acids, on wheat symbiosis with arbuscular mycorrhizal fungi |
| Institution Department and Address | Crop Science Centre, University of Cambridge, 93 Lawrence Weaver Road |
| Cambridge, Cambridgeshire CB3 0LE |
| United Kingdom |
| Full Name of Supervisor | Jeongmin Choi |
| Date of Project Commencement | 24/06/2023 |
| Duration (weeks) | 10 |
| Brief Description of Project | Producing sufficient food for a growing population while limiting the negative impact of agriculture on our environment is a major global challenge. Finding stable genetic solutions to develop disease-resistant crops would reduce our reliance on pesticides. However, it is important to fully understand the potential unintended consequences of selecting disease-resistant crops, such as an impact on beneficial plant-microbe interactions such as arbuscular mycorrhizal (AM) symbiosis. Approximately 80% of land plants in nature obtain minerals through this association. In addition to nutritional benefits, symbiosis confers improved disease tolerance against diverse pathogens. Here, we aim to evaluate whether improving the plant immune system is compatible with establishing and maintaining AM symbiosis by focusing on the plant hormone jasmonic acid (JA). JA is a powerful means to improve disease tolerance against fungal pathogens. For example, a wheat cultivar with increased JA signalling showed enhanced tolerance against the most devastating leaf disease, Septoria tritici blotch, which causes up to 40% yield loss. This makes the JA signalling an attractive breeding target to minimise fungicide use and yield loss. By contrast, the effect of JA signalling on AM symbiosis in wheat remains unknown. In another monocot, rice, JA treatment suppressed the symbiosis. Based on the close phylogenetic association between rice and wheat, I hypothesise that enhanced JA signalling will inhibit AM symbiosis in wheat while providing enhanced disease protection. To test this, we will take a genetic approach to address the effect of JA on AM symbiosis in the agronomically important cereal, wheat. WRKY10 transcription factor is a negative regulator of JA, and its down-regulation increased wheat susceptibility to Septoria disease. We will examine the AM symbiosis levels of WRKY10 overexpression, RNAi lines and control wheat. The student will perform the following experiments. 1. Characterise transgenic wheat lines by genotyping and gene expression analyses. 2. Perform an AM symbiosis colonisation assay in wheat. 3. Evaluate AM symbiosis levels by counting fungal structures (hyphopodium, intraradical hyphae, arbuscules, etc vesicles) under a brightfield microscope and confirm the visual inspection with AM marker gene expression using qRT-PCR. 4. Examine the defence responses during AM symbiosis by examining defence marker gene expressions using qRT-PCR. 5. Process the data and generate publishable figures using the R program, Image J and Adobe Image Suites. Overall, the outcome of the research program will provide strong evidence to support that JA-mediated disease resistance against necrotrophic fungal pathogens could compromise beneficial fungal association in roots. In the future, leaf-specific induction of JA signal activation could improve leaf pathogen resistance while harnessing the benefits of AM fungal symbiosis. |
| Attach the recommended reading for the project | 1. Campanaro, A., Srivastava, A.K., Zhang, C., Lee, J., Millyard, L., Gatehouse, A.M.R., Byrne, E. and Sadanandom, A. (2021), TaWRKY10 transcription factor is a novel jasmonic acid signalling regulator involved in immunity against Septoria tritici blotch disease in wheat. Plant Pathol., 70: 1397-1408. https://doi.org/10.1111/ppa.13388 |
| 2. Gutjahr C, Siegler H, Haga K, Iino M, Paszkowski U (2015) Full Establishment of Arbuscular Mycorrhizal Symbiosis in Rice Occurs Independently of Enzymatic Jasmonate Biosynthesis. PLOS ONE 10(4): e0123422. https://doi.org/10.1371/journal.pone.0123422 |
