Poster: Secondary Metabolism

Abs # 273: Antimicrobial Activities of Anthers in Tulips

Presenter:	Shoji, Kazuaki , shoji@agri.pref.toyama.jp
Authors	Shoji, Kazuaki  (A)
Affiliations:	(A): Biotechnology section, Toyama Agricultural Research Center

Phytoanticipins are plant-formed antibiotics that are produced according to normal plant development and are distinguished from phytoalexins synthesized in response to attacks by pathogens. Cultivated tulips (Tulipa gesneriana) synthesize antimicrobial glycosides, tuliposide A and B, and their lactonized aglycones, tulipalin A and B, as the phytoanticipins. Tuliposide D and F were also found from the wild-type species (Tulipa turkestanica and Tulipa sylvestris). To study the tissue specificity of antibiotics of tulip (cv. Murasakisuisho), antimicrobial activity was examined using various tissues. In this process, the highest activity was found to be present in anthers which were not reported so far. Purification and analysis of water-soluble substances from them revealed the cause of it as tuliposide B and tuliposide A was not detected. By the antimicrobial susceptibility tests, tuliposide B was found to be a strong sterilizer on bacteria regardless of gram-positive or -negative trait but have no effect on fungi. So, the production and accumulation of tuliposide B in anthers were thought to protect the pollens from bacterial pollutions for a long time. From the analysis of 90 cultivars and 30 wild-type species, various concentration of tuliposide B in anthers were shown irrelevant to pollen producibilities. One cultivar and five wild-type species that were not able to detect any antimicrobial activities were also found. They may be useful for the analysis of metabolic synthesis of tuliposide B or chemotaxonomic studies of genus Tulipa.