Heterocyte glycolipids indicate polyphyly of stigonematalean cyanobacteria

Publication date: October 2019Source: Phytochemistry, Volume 166Author(s): Thorsten Bauersachs, Scott R. Miller, Muriel Gugger, Opayi Mudimu, Thomas Friedl, Lorenz SchwarkAbstractThe cyanobacterial phylum is currently divided into five subsections (I–V), with the latter two containing no or false-branching (nostocalean) and true-branching (stigonematalean) cyanobacteria. Although morphological traits (such as cellular division and secondary branches) clearly separate both types of heterocytous cyanobacteria, molecular evidence indicates that stigonematalean cyanobacteria (Subsection V) do not form a monophyletic group but instead are interspersed and nested within the nostocalean cyanobacteria (Subsection IV). To further resolve the phylogeny of heterocytous cyanobacteria, we here analyzed the distribution of heterocyte glycolipids (HGs) in the true-branching cyanobacterium Stigonema ocellatum SAG 48.90 (type genus of Subsection V) and compared it with the HG inventory of other stigonematalean and nostocalean cyanobacteria. The most dominant HGs in S. ocellatum SAG 48.90 were 1-(O-hexose)-27-keto-3,25-octacosanediol (HG28 keto-diol) and 1-(O-hexose)-3,25,27-octacosanetriol (HG28 triol), which together constituted ca. 94% of all HGs. In addition, 1-(O-hexose)-3-keto-27-octacosanols (HG28 keto-ols), 1-(O-hexose)-3,27-octacosanediols (HG28 diols), 1-(O-hexose)-3-keto-27,29-triacontanediol (HG30 keto-diol) and 1-(O-hexose)-3,27,29-triacontanetriol (HG30 triol) occurred in minor...

Source: Phytochemistry - July 5, 2019 Category: Chemistry Source Type: research