Abstracts of papers to be presented at the 10th International Phycological Congress Orlando, Florida, USA 4-10 August 2013 Held under the auspices of the International Phycological Society Edited by: M. Dennis Hanisak, James A. Nienow & Akshinthala K. S. K. Prasad Copies of the abstracts will be provided to registered delegates at the 10th International Phycological Congress. The abstracts are arranged in alphabetical order by first author, presenting authors are listed in bold. Phycologia Journal of the International Phycological Society Volume 52, Number 4, supplement July 2013 Description of the Congress Logo The three macroalgae in the logo represent the three major taxa of eukaryotic macroalgae; all are native to Florida. The central position of Halymenia floridana J. Agardh [Halimenia floridana] in the logo represents phycologists coming together in Florida. The other two algae represent the international nature of Phycology and the IPC. The alga forming the base of the logo is Caulerpa mexicana Sonder ex Kützing. While named for its type locality in the country of Mexico, it is found not only in Mexico and Florida, but also in warm waters of many other parts of the world. Bracketing the logo along both sides is Sargassum natans (Linnaeus) Gaillon, a pelagic macroalga found throughout the North Atlantic; as is the case with phycology, individuals of this species know no national boundaries. The images were modified from C. W. Schneider and R.B. Searles‘s 1991 monograph Seaweeds of the Southeastern United States: Cape Hatteras to Cape Canaveral, with their kind permission. Charles D. Amsler and M. Dennis Hanisak Local Organizing Committee, IPC10 1 ____ IN NARRAGANSETT BAY (RHODE QUALITATIVE AND QUANTITATIVE ISLAND, USA) ANALYSIS OF EXO-POLYSACCHARIDES FROM INDIGENOUS RHIZOSPHERIC T. Aires1, C. Thornber1 and J. D. Swanson2 CYANOBACTERIA ([email protected]) 1University of Rhode Island, USA 2 M. Ahmed1, L. J. Stal2 and S. Hasnain1 Salve Regina University, USA ([email protected]) The macroalga Ulva rigida develops into harmful 1University of the Punjab, Pakistan 2Netherlands Institute of Ecology-KNAW, Netherlands blooms in shallow coastal systems worldwide, including Narragansett Bay, RI. These blooms have Exo-polysaccharide (EPS) is an important trait of the significant negative ecological and economic impacts majority of cyanobacteria that performs multiple on coastal communities. However, few data exist on functions. Physio-chemical analysis of EPS from mechanisms underlying functional genetics that link locally isolated rhizospheric cyanobacterial strains and bloom dynamics to environmental changes, especially their comparison was the main aim of the current with respect to global warming. Individuals from pre- study. Eight cyanobacterial isolates,four unicellular bloom, bloom, and post-bloom stages were collected and four filamentous, were used. Three different EPS during spring and summer 2012, along with relevant fractions, i.e., released (REPS), loosely bound (LEPS) ecological distributional data. RNA was extracted and closely bound (CEPS), were isolated separately from samples representing these three time periods from axenic cultures. Total protein and carbohydrate (May, July and September 2012) and preliminary content was also estimated. Eight different results using Real Time PCR showed differences in the monosaccharides were analysed in all EPS fractions expression of LhcSR, a gene that plays an important using the HPAE-PAD technique. EPS layers outside role in photo-protective mechanisms, with an the cyanobacterial cells were localized by confocal increased gene expression during summer. We are laser scanning microscopy (CLSM) using fluorescent preparing libraries to use an Illumina HiSeq dyes and lectins. Cyanobacterial isolates demonstrated transcriptome sequencing approach to characterizing a great variation in their EPS quantity and quality. and annotating the transcriptomes. Ultimately, we will CLSM revealed thick EPS increments on compare the gene expression patterns found for Ulva cyanobacterial strains, especially on rigida during bloom periods with those from non- Chroococcidiopsis strains (MMG-5 and MMG-6), bloom Ulva rigida. We anticipate that the whereas in filamentous strains released EPS was more transcriptomes will be highly similar among visible. Quantitatively CEPS was the most abundant temperatures and that the critical regulators may be fraction constituting more than 50% of the total EPS of expressed at low levels. all strains. REPS contained the highest total carbohydrate content as compared to other fractions. 3 Six monosaccharides, i.e. fucose, galactose, glucose, STRUCTURAL EVOLUTION OF mannose, rhamnose, and xylose, were found to be the MITOCHONDRIAL GENOMES IN EARLY most commonly occurring residues in EPS of isolates. DIVERGING ALGAL LINEAGES Fructose was found to be most common in Chroococcidiopsis strains. The EPS was found to be 1 2 1 very diverse in nature and different fractions showed J. L. Allen , R. M. McCourt and K. G. Karol specific characteristics. This can be a source of ([email protected]) 1The New York Botanical Garden, USA interesting polysaccharides of desirable characteristics 2 The Academy of Natural Sciences of Drexel University, USA in biotechnology. Prasinophytes are a paraphyletic assemblage of green 2 algae that include the earliest diverging lineages in DIFFERENTIAL GENE REGULATION Chlorophyta. These single-celled, planktonic PATTERNS, DURING BLOOM AND NON- organisms are found in marine and freshwater habitats BLOOM TIME PERIODS, OF ULVA RIGIDA worldwide. Lineages are recognized by characters 1 associated with scale morphology, flagellar apparatus, such as warming and declining consumer pressure. In and cell division processes. Our ability to test this study, we tested whether the presence of hypotheses about early algal evolution is limited consumers influenced the interactive effects of ocean because relationships among these lineages are poorly acidification and warming on benthic microalgae in a understood. Seven distinct prasinophyte clades have seagrass community mesocosm experiment. Net been identified (Clades I-VII), and four completely effects of acidification and warming on benthic sequenced mitochondrial genomes from Clades II, III, microalgal biomass and production, as assessed by and V are available. We generated mitochondrial analysis of variance, were relatively weak regardless genomes from three additional lineages (Clade I, IV of grazer presence. However, partitioning these net and VI) and increased taxon sampling in the effects into direct and indirect effects using structural Mamiellales (Clade II), the most diverse group of equation modeling revealed several statistically strong prasinophytes. Typically, green plant mitochondrial relationships. Our analyses highlight that (i) indirect genomes do not contain an inverted repeat (IR); an effects of climate change may be at least as strong as architectural feature common in plastid genomes that direct effects, (ii) grazers are crucial in mediating these minimally contains small and large subunit ribosomal effects and (iii) effects of ocean acidification may only genes. However, of the completed mitochondrial be apparent through indirect effects, and in genomes sequenced across green plants, two combination with other variables. These findings prasinophyte mitochondrial genomes from the highlight the importance of experimental designs and Mamiellales (Clade II) have been found to contain IRs. statistical analyses that allow us to separate and Interestingly, these mitochondrial IRs also include quantify the direct and indirect effects of multiple ribosomal genes. Newly sequenced mitochondrial climate variables on natural communities. genomes from Pyramimonadales (Clade I) and Chlorodendrales (Clade IV) also contain IRs, while 5 those from Mamiellales (Clade II) and Prasinococcales CYANOBACTERIA IN SOILS FROM A (Clade VI) include members that have an IR and other MOJAVE DESERT ECOSYSTEM members that do not, which illustrates the plasticity of this architectural feature in prasinophyte mitochondrial A. A. Alwathnani1 and J. R. Johansen2 genomes. Inverted repeats have not been identified in ([email protected]) mitochondrial genomes from representatives of Clades 1King Saud University, Saudi Arabia III and V, and mitochondrial genomes have not yet 2John Carrol University, USA been sequenced from representatives of Clade VII. Details of genome architecture, gene content, and The Fort Irwin National Training Center in the Mojave evolutionary relationships among prasinophyte Desert of California contains soils that represent a lineages will be discussed. diversity of disturbance regimes, including some soil sites that have been protected from anthropogenic 4 disturbance for many years. Previous studies of the CONSUMERS MEDIATE THE EFFECTS OF soils of this military installation discussed EXPERIMENTAL OCEAN ACIDIFICATION biogeography and ecology of the crusts but did not AND WARMING ON PRIMARY conduct detailed study of the species present. In this PRODUCERS study, we selected 6 sites in and around the Fort Irwin Training Center to be the subject of intensive isolation 1 2 1 efforts. These sites contained at least some C. Alsterberg , J. S. Eklöf , L. Gamfeldt , J. 1 1 development of microbiotic soil crust. Out of the more Havenhand and K. Sundbäck than 90 cyanobacterial isolates characterized, only 23 ([email protected]) 1University of Gothenburg, Sweden distinctive morphospecies