Ghent University develops green vaccine against the potato plague

(27-08-2021) Ghent University researchers led by Professor Geert Haesaert have developed a green vaccine against the potato pest.

Aardappelplaag.PNGThe most common potato disease is still the potato blight caused by Phytophthora infestans. The plants are usually treated with fungicides for this, but these cause exotoxicological effects partly due to the high frequency of treatment in certain growing seasons. A team of Ghent University researchers from the Faculty of Bioscience Engineering, led by Professor Geert Haesaert and in collaboration with the laboratory of applied mycology and phenomics led by professor Kris Audenaert found a sustainable alternative. As with a vaccine, the plant shows an increased resistance to the disease.

Phytophthora causes large yield losses. ‘On unprotected potato fields, the pathogen can cause the entire harvest to fail in a period of 7 to 10 days,’ says Professor Haesaert. To protect themselves against this, most growers rely on repeated fungicide treatments. However, the EU’s green deal foresees a 50% reduction in the use of conventional fungicides, making the need for a green alternative greater than ever. ‘Our research group started a search for alternatives, including a possible effect of Green Leaf Volatiles or GLVs on the resistance of the potato plant to the potato pest.’

Professor Haesaert: ‘GLVs are volatile organic compounds that are released when plants suffer tissue damage, such as when mowing grass. Some of these natural substances can give signals to other plants, for example increasing tolerance to plant diseases.’ This unique ability to suppress plant diseases has not yet been studied for Phytophthora. Within the Cropfit consortium, the Plant and Crop department of Ghent University set to work with the Bintje, a popular potato variety that is very sensitive to the plague.

Aardappelplaag II.PNGPotato plants were exposed to a GLV called Z-3-HAC, which also produces the typical odor of grass clippings, before being infected with late blight at various times. ‘We observed that the pre-exposed potato plants showed typical hypersensitivity symptoms indicating activation of the resistance mechanism in the treated plants. The result was a clear reduction in disease intensity,’ says Professor Haesaert. ‘Through more gene expression research, it could be shown that the GLV activates various defense-related genes, causing the plant to go into an enhanced self-defense mode.’

The discovery is a major victory over the potato plague, yet additional steps are needed. ‘Optimization of dosage and formulation and targeted modification of GLVs to enhance the defense responses in potato plants offer great potential for sustainable control of potato diseases,’ concludes Professor Haesaert.

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In collaboration with the Ghent University Crelan chair of agricultural innovation