Interaction DNA-DNA between the endophyte Microspongium tenuissimum and his host the marine alga Grateloupia imbricata

Abstract

Macroalgae form habitat for a variety of other organisms from virus and bacteria to other algae that live as a passive epiphytes and endophytes, or causing infection. Structural intimate association among the participating algae is quite common. Grateloupia imbricata (Holmes) is a red alga that grown along the northeast coast of Gran Canaria, Canary Island (Spain). Grateloupia imbricata is infected by a microscopic endophyte identified as Microspongium tenuissimum (Hauck) via phylogenetic analysis inferred from ITS-5.8S rDNA. In Vitro culture showed high rate of infection, up 90 %. The infection by Microspongium tenuissimum was revealed by PCR, occurring in all thalli of Grateloupia imbricata. This process is repeated for three different populations in the coast of Gran Canaria. The strong structural interaction between host and its endophytes has been reported, however it has not been investigated at the molecular level. We performed a Southern blot analysis with a specific dioxigening-labeled DNA probes for Microspongium tenuissimum which revealed an relevant interaction at DNA level between of the endophyte Microspongium tenuissimum and its host Grateloupia imbricata. In addition, these results did not figure out the role of the interaction. However, this interaction improve the knowledge about the relationship between hosts and endophytes, especially for biotechnology such as algal transformation.