The conifer biomarkers dehydroabietic and abietic acids are widespread in Cyanobacteria

• Published in: Scientific Reports
• Main Authors: Costa M.S., Rego A., Ramos V., Afonso T.B., Freitas S., Preto M., Lopes V., Vasconcelos V., Magalhães C., Leaõ P.N.
• Other Authors: CIIMAR - Centro Interdisciplinar de Investigação Marinha e Ambiental
• Format: Article in Journal/Newspaper
• Language: English
• Published: Nature Publishing Group 2016
• Subjects: McMurdo Dry Valleys; New Zealand; Antarc*; Antarctica; Antarctica New Zealand
• Online Access: https://hdl.handle.net/10216/120310; https://doi.org/10.1038/srep23436

Terpenes, a large family of natural products with important applications, are commonly associated with plants and fungi. The diterpenoids dehydroabietic and abietic acids are defense metabolites abundant in resin, and are used as biomarkers for conifer plants. We report here for the first time that the two diterpenoid acids are produced by members of several genera of cyanobacteria. Dehydroabietic acid was isolated from two cyanobacterial strains and its identity was confirmed spectroscopically. One or both of the diterpenoids were detected in the cells of phylogenetically diverse cyanobacteria belonging to four cyanobacterial 'botanical orders', from marine, estuarine and inland environments. Dehydroabietic acid was additionally found in culture supernatants. We investigated the natural role of the two resin acids in cyanobacteria using ecologically-relevant bioassays and found that the compounds inhibited the growth of a small coccoid cyanobacterium. The unexpected discovery of dehydroabietic and abietic acids in a wide range of cyanobacteria has implications for their use as plant biomarkers. We thank CEMUP for NMR and MS analyses. We also thank João Morais for the microphotographs of the strains and Aldo Barreiro Felpeto for the collection of subtidal samples. We would also like to acknowledge funding from Fundação para a Ciência e a Tecnologia (FCT) through grants PTDC/MAR-BIO/2818/2012, a FCT Investigator contract to PNL (IF/01358/2014) and fellowship SFRH/BD/80153/2011 to VR. This research was partially supported by the Strategic Funding UID/Multi/04423/2013 from FCT and the European Regional Development Fund (ERDF). We are sincerely grateful to Antarctica New Zealand and Portuguese Polar Program (PROPOLAR) for providing logistics support to Antarctica McMurdo Dry Valleys field campaign