Morphological data combined with molecular evidence show that they constitute three new species, for which the names, P. batesiana sp. nov., P. lundholmiae sp. nov., and P. fukuyoi sp. nov., are proposed. The three new species closely resemble species in the P. pseudodelicatissima complex sensu lato. Morphologically, P. batesiana differs from other species in the complex by having a smaller part of cell overlapping in
the chain, whereas P. lundholmiae differs by having fewer poroid sectors and P. fukuyoi by having a distinct type of poroid sectors. Nucleotide sequences of the LSU rDNA (D1–D3) of the three new species reveal significant nucleotide sequence divergence (0.1%–9.3%) from each other and from other species in the P. pseudodelicatissima complex s.l. The three species are phylogenetically closely related to species in the P. pseudodelicatissima buy CP-673451 complex, with P. batesiana appearing as a sister taxon to P. circumpora, P. caciantha, and P. subpacifica; whereas P. lundholmiae and P. fukuyoi are more
Galunisertib mw closely related to P. pseudodelicatissima and P. cuspidata. The three species show 2–3 compensatory base changes (CBCs) in their ITS2 transcripts when compared to the closely related species. The ITS2 with its structural information has proven its robustness in constructing a better resolved phylogenetic framework for Pseudo-nitzschia. “
“Macroalgae of the order Laminariales (kelp) are important components of cold-temperate coastal ecosystems. Major factors influencing their distribution are light including UV radiation and temperature. Therefore, future global environmental changes potentially Tryptophan synthase will impact their zonation, distribution patterns, and primary
productivity. Many physiological studies were performed on UV radiation and temperature stress in kelp but combinatory effects have not been analyzed and so far no study is available on the molecular processes involved in acclimation to these stresses. Therefore, sporophytes of Saccharina latissima were exposed for two weeks to 12 combinations of photosynthetically active radiation, UV radiation and temperature. Subsequently, microarray hybridizations were performed to determine changes in gene expression patterns. Several effects on the transcriptome were observed after exposure experiments. Strongest effect of temperature on gene expression was observed at 2°C. Furthermore, UV radiation had stronger effects on gene expression than high PAR, and caused stronger induction genes correlated to categories such as photosynthetic components and vitamin B6 biosynthesis. Higher temperatures ameliorated the negative effects of UV radiation in S. latissima. Regulation of ROS scavenging seems to work in a compartment specific way. Gene expression profiles of ROS scavengers indicate a high amount of oxidative stress in response to the 2°C condition as well as to excessive light at 12°C.