In nature, there exist intricate interactions between plant viruses and their insect vectors. More than 75% of plant viruses rely on insects, such as aphids and whiteflies, to overcome physical barriers and spread among host plants. Turnip Yellows Virus (TuYV), a circulative virus, promotes its own spread by altering the behavior and physiological responses of its primary aphid vector, Myzus persicae. Although it is known that TuYV infection can affect aphid feeding preferences, orientation, and fertility, the underlying molecular mechanisms remain incompletely understood. Previous research has indicated that certain viral proteins can directly or indirectly modify the behavior of vector insects, yet which specific viral factors are responsible for these behavioral changes remains unclear.
Recently, a research paper titled “The Turnip Yellows Virus Capsid Protein Promotes Access of Its Main Aphid Vector Myzus persicae to Phloem Tissues” was published in Plant, Cell & Environment. This study aimed to explore how TuYV influences the behavior of its main vector, Myzus persicae, and the role of viral proteins such as the capsid protein (CP) in this process.
This research discovered that plants infected with TuYV can significantly change aphid feeding behavior. Specifically, aphids spend less time in the path – phase on these plants and more time sucking phloem sap. This change enables aphids to more efficiently obtain the limited TuYV viruses in the phloem. Compared to wild – type plants, aphids on TuYV – infected plants and transgenic plants expressing CP exhibit longer phloem – sap – sucking periods and shorter path – phases. Further research revealed that this alteration in feeding behavior can be completely replicated by the phloem – specific expression of CP in transgenic plants, while the expression of the P0 protein has a minor impact and the RT protein has no significant effect. These results demonstrate that the CP protein plays a crucial role in regulating aphid feeding behavior. The feeding behavior of aphids on CP – transgenic plants is highly similar to that on TuYV – infected plants, thus confirming the importance of the CP protein in the interaction between TuYV and aphids.
In addition, metabolomic analysis showed that there are specific metabolites in TuYV – infected plants and CP – transgenic plants. These metabolites may be the cause of the altered aphid feeding behavior. Among them, a metabolite, M649T530, accumulates only in TuYV – infected plants and CP – transgenic plants and may be a candidate substance responsible for the change in aphid feeding behavior. M649T530 is significantly upregulated in both TuYV – infected plants and CP – transgenic plants.
This study reveals how TuYV modifies the feeding behavior of its primary aphid vector through its CP protein to promote virus spread, which is of great significance for understanding the interaction between plant viruses and vector insects. The research not only enhances our understanding of the molecular mechanisms by which viruses manipulate host plants to influence vector behavior but also provides potential molecular targets for the development of new virus – control strategies, contributing to reducing the spread and impact of viral diseases in agriculture.
When it comes to plant virus disease prevention, chitosan oligosaccharide has emerged as a promising solution. Chitosan oligosaccharide, a natural polysaccharide derivative, has been shown to possess antiviral properties. It can enhance the plant’s immune system, making plants more resistant to TuYV and other plant viruses. By activating the plant’s defense – related genes, chitosan oligosaccharide can induce the production of various defense – related substances, such as pathogenesis – related proteins and phytoalexins. These substances can directly inhibit the replication and spread of viruses in plants. Moreover, chitosan oligosaccharide can also modify the plant cell surface, making it more difficult for virus – carrying aphids to attach and infect. Combining the understanding of the TuYV – aphid interaction mechanism with the application of chitosan oligosaccharide holds great potential for developing more effective strategies to combat plant virus diseases, safeguarding crop yields and agricultural sustainability.