Abstract
Actinomycetes Frankia have symbiotic ability to form nitrogen-fixing nodules on roots of actinorhizal plants. To screen Frankia genes involved in symbiosis, root exudate of its host actinorhizal plant was used.
Cultures of Frankia sp. strain CcI3 were treated by root exudate of its symbiotic host plant, Casuarina glauca and a non-host plant, Alnus glutinosa respectively. Suppression subtractive hybridization (SSH) is a powerful technique for screening differentially expressed cDNAs. Although SSH was originally designed for eukaryotic mRNA, we achieved the application of SSH to prokaryote Frankia preparing eukaryote-like mRNA. CcI3 total RNA was removed 16S and 23S ribosomal RNA and add poly(A) tail by RNA poly(A) polymerase. Using this technique, we are trying to screen CcI3 genes specifically induced by root exudate of the host plants.
