Undergraduate Student Report 2021

Investigating the effect of elevated CO2 in resistance to powdery mildew, caused by the fungal pathogen Erysiphe alphitoides, in 150-year-old oak trees.

Emma Ann Platt

Emma Ann Platt worked with Dr Estrella Luna-Diez, University of Birmingham, to study the effect of elevated CO2 on resistance to the fungal plant pathogen Erysiphe alphitoides

EAP 1.jpgDuring my studentship with Dr Estrella Luna Diez and her colleagues, I assisted with their project into investigating the effect of elevated CO2 in resistance to powdery mildew in mature oak trees. I was involved in many aspects of the project, such as mature oak leaf collection from the field, leaf sorting, scanning, and analysis of them for powdery mildew infection area.

The mature oak tree leaves were collected from the free air CO2 enrichment (FACE) facilities of the Birmingham Institute of Forest Research (BIFoR). BIFoR-FACE is a facility, with multiple elevated CO2 and ambient arrays (pumping in CO2 at ~550ppm and ambient air, respectively), allowing the effects of climate change to be studied on this mature forest.

The collected mature oak leaves from both the elevated CO2 and ambient arrays were scanned and uploaded to ImageJ, where powdery mildew pixel number was calculated. This procedure was developed and carried out by me and two other colleagues. A macro was then generated based on these using imageJ software, allowing all the scanned images to be inputted at once, and powdery mildew percentage to be calculated semi-automatically.

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Mature oak leaf scanning in the lab.

The percentages for the elevated CO2 and ambient arrays were compared in order to investigate the difference between their impact on the mature oak tree resistance to powdery mildew. Based on this analysis, there was no evidence of any differences between the resistance of mature oak leaves to powdery mildew infection, of the elevated CO2 and ambient arrays. However, further investigation is required in order to conclude the lack of relationship between CO2 concentration and powdery mildew infection, as there were differences found in specific years.

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A tower inside one of the arrays at the BIFoR-FACE facility.

In addition to the results that we found during this project, I learnt many hands on and computational skills during my studentship. For example, I learnt how to detect powdery mildew on oak leaves, how to undertake a powdery mildew infection, how to use ImageJ, and how to create a macro. These are skills that I will carry forward into my studies and future working life. However, the most profound thing that I have learnt from this project is that I am extremely interested in scientific research and would like to undertake a PhD in a related line of research in the future.