USA - The functions of root border cells in Picea abies, Pinus and agricultural species: common strategies for different challenges?

As plants are bound to live stationary lives, their roots have to cope with a number of challenges that may differ between species and change through the plants' life cycle. For example, a tree seedling in a plant school must withstand attacks by the soil born Pythium fungus, while a mature tree must cope with soil containing aluminium and Heterobasidion spores. A wheat plant may experience aluminium rich soil, while a corn plant combats nematode attacks. Although survival measures may differ in many respe cts, recent research by independent groups points to one possibly common strategy across different species, namely the use of root border cells. These cells, first described in 1920, are living cells detached from the root cap. They have been shown to hav e their own metabolism that is different from that of the root itself. They seem to defend roots against Al toxicity by exuding mucilage that binds Al, and against attacks by fungi and nematodes. Thus, they have the ability to affect rhizosphere processes and are important for crop and tree health. The genes involved in these functions are, however, not yet well known. In this preproject two groups from Skogforsk and the University of Arizona will start a cooperation to share their knowledge on border cel ls and techniques to study them. The Norwegian group has studied Norway spruce border cells, the American group has studied border cells from pine and agricultural species. By using different techniques for studying gene expressions we want to find out so me of the similarities between the species when it comes to how they produce their border cells and how they use them to protect themselves and remain healthy. These studies will be done by cooperation during mutual research visits.