Guizhou University researchers identify molecular pathway behind oligochitosan-induced plant immunity against potato virus Y

Guizhou University study reveals how oligochitosan uses the OXI1 gene to trigger plant immunity against PVY, offering a green alternative to pesticides.

By: AXL Media

Published: Apr 30, 2026, 9:09 AM EDT

Source: Information for this report was sourced from EurekAlert!

Green Solutions for Devastating Agricultural Viruses

Oligochitosan has emerged as a critical biological tool in the sustainable management of crop diseases, known for its ability to prime plant immune systems against various pathogens. Despite its established success against tobacco mosaic virus, its specific interaction with potato virus Y remained largely misunderstood until recently. PVY is a destructive pathogen responsible for massive yield losses in tobacco and potato sectors, particularly within developing nations. To address this knowledge gap, a research group at Guizhou University conducted a comprehensive study to determine how this environmentally friendly inducer fortifies plant defenses. According to the findings published in Frontiers of Agricultural Science and Engineering, oligochitosan acts as a catalyst for internal defense mechanisms rather than a direct toxin to the virus.

Biochemical Strengthening of Plant Defenses

The experimental phase of the study focused on Nicotiana benthamiana as a model plant, testing the efficacy of oligochitosan at a concentration of 100 micrograms per milliliter. The results were significant, showing a preventive efficacy of 54.7% against PVY infection. Beyond just reducing visible damage, biochemical testing revealed a surge in defense-related enzymes, including catalase, peroxidase, and superoxide dismutase. According to Academician Baoan Song, these treatments also increased hydrogen peroxide content within the plants. These chemical changes collectively serve to harden the plant's physiological response, creating a hostile environment for viral replication and spread.

Mapping the MAPK Signaling Cascade

Through the integration of transcriptomic and proteomic analyses, the researchers were able to visualize the molecular conversation occurring within the plant cells. The treatment with oligochitosan was found to induce the differential expression of several key genes, specifically OXI1, NDPK4, and MAPKKK21. These genes are intrinsically linked to reactive oxygen species signaling and the mitogen-activated protein kinase pathway. The study clarifies that oligochitosan specifically targets the upregulation of the OXI1 gene, which then triggers a domino effect through the MAPK cascade. This internal signaling is what eventually manifests as heightened resistance to the PVY pathogen.