This is the report from a BSPP MSc/MRes Bursary.
Click here to read more/apply for one yourself.
During the academic year of 2022/2023 I had the incredible opportunity to work with Professor Mahmut Tör and investigate the impact of biological control agents on pea plant leaves microbiome at the University of Worcester. This research project was worth 60 credits towards my Integrated Masters in Biochemistry. In the following I will provide an overview of my project.
Downy mildew (DM) is one of the most destructive diseases for peas – it is caused by the pathogen Peronospora viciae f. sp. pisi (pvp). Unfortunately, there are not effective ways to control this pathogen because the fungicide utilised (Wakil XL) was removed from the UK market due to safety concerns. The lack of sufficient control measures has led to a need for alternatives. One such alternative is biological control agents (BCAs). BCAs are microbes which can work antagonistically to suppress infection.
In my thesis I tested two novel BCAs which are being investigated for the suppression of DM to determine their impact on the plants indigenous microbiome. This work is necessary because the plant leaf microbiome is vital for providing resistance to other pathogens and pests as well providing support against abiotic stresses (e.g. drought). Therefore, if the microbiome is dramatically altered by the addition of BCAs it may be detrimental to plant growth.
The two BCAs I tested were Bacillus subtilis EU07 and Pseudomonas fluorescens. I also tested a 50/50 combination of the two BCAs as research suggests that a combination may provide a greater level of suppression. In the infographic below is a brief version of the methodology used, in short the BCAs were applied to pvp infected plants, the microbiome was extracted and sequenced and the sequencing data was then analysed using bioinformatic pipelines. Sadly, during the bioinformatic analysis I ran into some problems and due to time constraints, the scope of the project had to be reduced to just bacterial communities.
Between 58% and 79% of the bacterial strains could not be taxonomically assigned so the information able to be extracted in this work is restricted. However, from what data was available the results suggest that the systemic infection of peas with pvp leads to changes in the bacterial community when compared to healthy peas. For the most part the addition of an individual BCA can return the bacterial communities to similar abundances to that of the healthy peas. Whilst the combination of both BCAs does not manage to match the abundances of the healthy peas suggesting that by mixing the BCAs their suppression is much greater and detrimental to indigenous microbes.
I would love to have managed to investigate the entirety of the microbiome and get more thorough results but that can be work for someone else in the future who is not under the same constraints as me.
I would like to say that I am very grateful for the support I have received via the BSPP Msc Bursary which helped me to finance the whole genome sequencing work conducted in the project. I would also like to express my gratitude to the Molecular Plant and Microbial Biosciences Research Unit at the University because they provided me with so much support. Whilst I am not staying in the field of plant pathology as I begin my path into becoming a science teacher this field will always hold a place in my heart following this hard but rewarding year.
Infographic of methodology utilised in my Masters project