The study results were published in the journal Plants.
According to the researchers, plant diseases caused by mycelia microorganisms (oomycete) are a serious problem for agriculture around the world. One such diseases – late blight or phytofluorosis – affects potatoes and tomatoes. Phytophthora infestans, the disease agent, causes the leaves of the potatoes to whither, the tuber to decompose and the plant to die.
"A common way to fight late blight is treating potatoes with pesticides. However, pathogens are becoming more and more resistant to chemical agents. Therefore, scientists are looking for alternative ways to protect plants", Alexey Vasilchenko, head of the Antimicrobial Resistance Laboratory at Tyumen State University and one of the authors of the study, said.
According to Vasilchenko, natural plant extracts used in medicine are a promising addition to chemical pesticides. Their use will reduce the amount of pesticide residues in food and the environment. Furthermore, it is a less expensive way to protect plants.
The research team from the Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, the Gause Institute of New Antibiotics, the All-Russian Institute of Plant Protection, the Institute of Environmental and Agricultural Biology (X-Bio) of Tyumen State University, and the Timiryazev Russian State Agrarian University have studied the influence of seven medicinal plants on late blight.
Greater celandine (Chelidonium majus), horse-heal (Inula helenium), common horsetail (Equisetum arvense), bay laurel (Laurus nobilis); green tea (Camellia sinensis), common Saint John's wort (Hypericum perforatum) were selected for the experiment.
Potato tubers were sliced into discs and treated with extracts. Researchers then observed late blight germination in laboratory conditions using optical microscopy.
According to the scientists, the results indicate the ability of peptide extracts to inhibit the formation of late blight symptoms (necrotic spots and sporiferous layers) for 144 hours after potato-disc treatment.
The study was supported by the Russian Science Foundation (Grant # 19-76-30005) and the Russian Foundation for Basic Research (Grant # 18-34-20058).
The research is carried out under the theme “Biosafety of humans, animals, and plants” of the West Siberian Interregional Research and Educational Centre (REC).