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Towards sustainable crop protection: biocontrol of blight.

Reference number
FFL12-0056
Start and end dates
140101-191231
Amount granted
9 700 000 SEK
Administrative organization
Swedish University of Agricultural Sciences
Research area
Life Sciences

Summary

Potato late blight caused by the oomycete Phytophthora infestans is a global threat to food security costing over 45 billion SEK annually. New control measures are timely and necessary. The aim of my research is to develop new ways to tackle oomycete diseases based on fundamental cell wall biology. Task one will investigate oomycete cell wall biology in P. infestans development and pathogenicity, to discover new targets for disease control. We will focus on two areas:(i) determining the function of P. infestans cell wall associated proteins, in oomycete biology and as antigenic molecules that elicit plant defences;(ii) gaining a thorough understanding of cell wall biosynthesis in P. infestans, focusing on the structural carbohydrate cellulose as a target for disease control. Task two will exploit the biological activity of the mycoparasitic oomycete Pythium oligandrum. P. oligandrum enhances plant growth and defences. It also parasitizes P. infestans. Efficient, synchronised germination of thick-walled oospores is essential to the use of this organism in biocontrol. Therefore, we will make a detailed study of the oospore cell wall throughout development and germination. To further investigate mycoparasitism we will characterise the cell wall associated effector CBEL elucidating the role of this protein in P. oligandrum-host interactions. Task 3, in partnership with industry, will focus on commercialising our results to deliver new controls for oomycete diseases.

Popular science description

Global food security is a grand challenge for our time. 50 % of all crops grown worldwide are lost due to pests and diseases. To feed the growing world population (9 billion by 2050) agriculture needs to become more efficient and sustainable. Late blight of potato and tomato is a devastating disease, up to 80 % of a crop may be lost, (at a global cost equivalent to at least 45 billion SEK per year. Late blight is caused by the oomycete Phytophthora infestans. Oomycetes look like fungi, but are genetically distinct, being closely related to brown algae. Phytophthora has a remarkable way of overcoming resistance in potatoes and the differences between oomycetes and the true fungi many fungicides are ineffective. For example potatoes are an important, albeit minor crop in Sweden, accounting for only 1 % of agricultural land use, however 60 % of all fungicides used in Sweden are directed at controlling potato late blight. This is both economically costly to our farming industry, but also highly environmentally damaging. Therefore new control measures need to be developed. My research vision is to develop new, environmentally sustainable ways to control late blight and related crop diseases based on fundamental cell wall biology. I have previously shown that the carbohydrate cellulose is an essential component of the late blight cell wall and Syngenta has developed anti oomycete drugs that target cellulose synthesis in these organisms. However this has not proved durable for crop protection. In this research project we will identify new targets for disease control in the oomycete cell wall by unravelling the fundamental science behind the biosynthesis of this essential protective cellular layer. We are also investigating the use of a related oomycete Pythium oligandrum as a novel biocontrol agent. Pythium is able to form beneficial associations with plant roots, enhancing growth and providing protection to the plant from fungal attack. Pythium also feeds like a cannibal, parasitizing other oomycetes or soil inhabiting pathogenic fungi and therefore offers a promising opportunity for environmental control of late blight. However we need to precisely control germination of Pythium spores to make this an effective treatment in agricultural systems. Our work therefore also seeks to uncover changes that occur in the cell wall of Pythium spores during germination and use this fundamental knowledge for rational design of new biocontrol measures against late blight.