From pathogen to prey: new insights into the role of effectors from Phytophthora infestans : pathogenicity, population biology, and defence

Sammanfattning

Late blight, caused by the highly adaptable oomycete Phytophthora infestans, is a global agricultural challenge. This thesis explores the role of effector proteins from P. infestans in pathogenicity, pathogen populations, and protection from mycoparasitic attack. Cell biology analyses reveal that P. infestans manipulates host metabolic pathways, including starch and lipid catabolism, to induce stomatal opening and facilitate sporulation. Effectors likely play a central role in bypassing host stomatal defences. To investigate effectors from a more environmental perspective two approaches were taken. Firstly, both the genetic diversity and local adaptation of Avr2 across China were studied to investigate the maintenance of effectors in pathogen populations. Environmental factors like temperature and altitude shape the variability of this effector. These findings emphasise the need for region-specific strategies in resistance breeding and predicting pathogen evolution under climate change. Secondly, the responses of P. infestans to attack by mycoparasitic oomycetes were investigated using transcriptomics. Differentially expressed genes involved in sensing, signal transduction, gene regulation, detoxification, and defence, uncover components of oomycete innate immunity for the first time and suggest P. infestans is well equipped to recognise these biocontrol agents. Finally, this thesis reviews challenges in implementing biocontrol of P. infestans in Europe, emphasising the need to integrate molecular insights into practical, sustainable disease management approaches. Collectively, this work advances our understanding of P. infestans as a highly adaptable pathogen capable of both manipulating hosts and responding to antagonists, providing a foundation for developing more targeted and sustainable late blight control strategies.

Nyckelord

Phytophthora infestans; late blight; effectors; stomatal manipulation; mycoparasite; biological control; Pythium; transcriptomics; population genetics

Publicerad i

Acta Universitatis Agriculturae Sueciae
2025, nummer: 2025:7
Utgivare: Swedish University of Agricultural Sciences

SLU författare

• Sundar, Jenifer Seematti

  • Institutionen för växtskyddsbiologi, Sveriges lantbruksuniversitet
    

UKÄ forskningsämne

Jordbruksvetenskap

Publikationens identifierare

• DOI: https://doi.org/10.54612/a.658nio3jt9
• ISBN: 978-91-8046-442-0
• eISBN: 978-91-8046-492-5

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/132947