Identification of genes involved in the symbiotic interactions in the lichen Xanthoria parietina

地衣至少由两种不同的生物组成，一种是藻类(光生物)，另一种是真菌(真菌)。它们通常形成一个高度分化的结构，即地衣叶状体。即使参与共生体之间的这种相互作用不是排他性的，许多共生体在它们的光生物选择上也是相当有选择性的，例如，叶状地衣Xanthoria parietina。双方都可以被分离到无菌培养中，并在实验室中单独培养。通过与这些分离物共培养，可以诱导再分化的第一步。这为研究地衣共生的分子机制提供了机会。共生体交换信号，导致紧密的代谢耦合(例如，藻类释放糖醇，随后由真菌生物体吸收和代谢)，最后对光做出反应，导致地衣藻体中的藻类进行光合作用的最佳安排。为了第一次深入了解地衣共生中信号交换的遗传基础，将确定参与共生体非常早期共生相互作用的基因。

Lichens are composed of at least two different organisms, an alga (photobiont) and a fungus (mycobiont). These form an often highly differentiated structure, the lichen thallus. Even if this interaction between the partaking symbionts is not exclusive, many mycobionts are rather selective in their photobiont choice, like, for example, the foliose lichen Xanthoria parietina. Both partners can be isolated into axenic cultures and cultivated separately in the laboratory. The first steps of the relichenisation can be induced by co-culturing these isolates. This offers the opportunity to study the molecular mechanisms underlying the establishment of lichen symbiosis. The symbionts exchange signals leading to close metabolic coupling (e.g. release of sugar alcohols by the alga and subsequent uptake and metabolism by the mycobiont) and finally responses to light, leading to an optimal arrangement of the algae in a lichen thallus to perform photosynthesis. Genes involved in the very early symbiotic interaction of the symbionts will be identified in order to gain first insight in the genetic basis of signal exchange in lichen symbiosis.