Influence of Chitooligosaccharides with Different Acetylation Degrees on the H2O2 Content and the Activity of Pathogenesis-Related Proteins in Potato Plants Infected with Phytophthora infestans

Resumo

The effect of chitooligosaccharides (ChOSs) with an acetylation degree (AD) of 65% and 30% on the formation of defense reactions of potato plants (Solanum tuberosum L.) against Phytophthora infestans (Mont.) De Bary is studied. The content of hydrogen peroxide, the activities of peroxidases, allene oxide synthase, and hydrolase inhibitors, and the transcriptional rate of pathogenesis-related (PR) proteins are studied. ChOSs with an AD of 65% reduced the degree of late blight symptoms on the leaves of potato plants via the stimulation of H₂O₂ accumulation and the transcriptional activity of genes encoding peroxidase (M21334), chitinase (U49969.1), and inhibitors of amylase (XM006351484) and proteinase (JX683427). It is found that ChOSs with an AD of 30% induced the activity of anionic isoperoxidases with a pI of ~3.5–4.5 in infected plants. The mechanisms of potato resistance to Phytophthora infestans formed under the influence of different ChOSs are discussed.