Plasmodesmata, not stomata, directly connect the plasma membrane and cytoplasm of neighboring cells, forming the intercellular symplast in plants.
Xiaokun’s research aims to address how plant pathogens promote infection via host cell-cell symplastic connectivity.
He hypothesises that pathogens benefit from the host intercellular communication in two ways: by delivery of mobile signals from invaded cells into adjacent, ‘to-be-invaded’ cells to promote disease; and by gaining access to resources from surrounding non-invaded plant cells.
To test the hypothesis, Xiaokun will use the compatible interaction between the oomycete pathogen Hyaloperonospora arabidopsidis (Hpa) and its host Arabidopsis to answer the two questions;
1. How does Hpa access the host symplast?
2. How does Hpa manipulate non-infected cells?
For question 1, Xiaokun will perform a large-scale screen of Hpa effectors to identify those that have intercellular mobility.
To answer question 2, he will compare global gene expression in the PD-closed lines and wild-type plants to identify host processes that are targeted by symplast mobile effectors.
This research will give insight into how PD-established symplastic connectivity is exploited by pathogens for infection and thus characterise an entirely novel component of infection strategies, thus will lay the foundation for future development of novel strategies to enhance plant resistance.