The Bartlem Lab
Research Faculty of Agriculture, Hokkaido University
Our research is focused on understanding the molecular mechanisms behind parasitic attack of plant roots by root-knot nematodes. Root-knot nematodes spend most of their life hidden deep inside plant roots feeding at one location. The successful infection of a plant root by root-knot nematodes is a fascinating process that involves a delicate interaction between the plant cells and the nematode animal.

Root-knot nematodes (abbreviated as RKNs) are a major parasite of agricultural crops. RKNs are responsible for the loss of approximately 5% of agricultural crops worldwide. RKNs have a very broad host range, and can infect over 500 different plant species. RKNs invade inside plant roots as a juvenile, where they then induce a specialised feeding site and become sedentary (settle at one location). The RKNs are then able to spend the remainder of their life at this one feeding site hidden deep inside the plant root. The formation of the feeding site causes galling of plant roots and disrupts normal root function. This restricts plant growth and leads to large reductions in plant yield. Safe, effective and sustainable methods for controlling RKNs in agriculture are urgently required. Our research provides an important contribution by trying to understand the molecular mechanisms used by RKNs to establish the infection site.

Studying the induction of the RKN feeding site
The specialised feeding site induced by RKNs is usually initiated within 24 hours after invasion of the host root. The RKN first selects normal plant cells near the vasculature and then secretes something into these cells to induce molecular changes within these cells. These plant cells then become enlarged, specialised feeding cells called “Giant Cells”. The major steps for infection of plants by root-knot nematodes are largely understood. However, the molecular mechanisms involved in the conversion of normal plant cells into Giant Cells remain unclear. By studying both the RKN parasite directly and the infected plant, we aim to discover how RKN infection sites are formed at the molecular level.

Using Micro-Tom to study the RKN infection process
We are using a dwarf tomato variety, called Micro-Tom. Tomato is one of the crops often damaged by RKNs, and Micro-Tom is just a different variety of normal tomato. Data obtained using Micro-Tom can therefore be directly applied to other domestic tomato varieties. Micro-Tom is a good plant for molecular research. It has a small size (~15cm), grows relatively fast and is easy to cultivate in laboratory incubators. Genetic and biological resources are rapidly increasing for both tomato and Micro-Tom thanks to the Tomato NBRP in Japan and the International Solanaceae Initiative (SOL). Micro-Tom is also easily grown in vitro on sterile medium, enabling controlled RKN infection studies.

The Lab
We have our lab set up with everything in the one room, including plant incubators, clean bench, freezers, etc. Our individual lab benches are arranged down the middle of the room, with all the equipment around the border of the room. We also have our plant incubators connected to web servers that log the temperature and humidity and send out alerts if conditions become abnormal. You can access current recordings by clicking on the following links: Glass Door Incubator Monitor and the Solid Door Incubator Monitor. (links currently not working - in process of moving!)

We don’t have any advertised positions at the moment, but if you are interested in our research and want to apply for one of the below fellowships, then please get in touch with Derek.
Postdocs: The Japan Society for Promotion of Science (JSPS) offers 2-yr postdoctoral fellowships to perform research in Japan. For more information, click here.
Summer students: The Japanese Society for Promotion of Science (JSPS) also has a summer program for postgraduate students from select countries to conduct summer research in Japan. For more information, click here.