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Nicolas A. Blouin – One of the best experts on this subject based on the ideXlab platform.
More than meets the eye: regional specialisation and microbial cover of the blade of Porphyra umbilicalis (Bangiophyceae, Rhodophyta)Botanica Marina, 2018Co-Authors: Charlotte J. Royer, Nicolas A. Blouin, Susan H BrawleyAbstract:
Completion of the Porphyra umbilicalis genome and ongoing research on this species by many investigators suggest the need for wider appreciation of regional specialisation of the P. umbilicalis blade. Here we use light and electron microscopy to describe four distinct regions of the blade: rhizoid cells with abundant floridean starch, vegetative cells, differentiating neutral sporangia, and mature neutral spores. The holdfast, densely covered by microorganisms, presents an intriguing biomechanical structure: thousands of very thin, long rhizoid tips course through the thick, secreted polysaccharide to the substratum. Wild blades in culture have more microorganisms than when collected, including filamentous cyanobacteria.
insights into the red algae and eukaryotic evolution from the genome of porphyra umbilicalis Bangiophyceae rhodophytaProceedings of the National Academy of Sciences of the United States of America, 2017Co-Authors: Susan H Brawley, Glen L Wheeler, Nicolas A. Blouin, Martin Lohr, E Fickoblean, Holly V Goodson, Jerry Jenkins, Crysten E Blabyhaas, Katherine E HelliwellAbstract:
Porphyra umbilicalis (laver) belongs to an ancient group of red algae (Bangiophyceae), is harvested for human food, and thrives in the harsh conditions of the upper intertidal zone. Here we present the 87.7-Mbp haploid Porphyra genome (65.8% G + C content, 13,125 gene loci) and elucidate traits that inform our understanding of the biology of red algae as one of the few multicellular eukaryotic lineages. Novel features of the Porphyra genome shared by other red algae relate to the cytoskeleton, calcium signaling, the cell cycle, and stress-tolerance mechanisms including photoprotection. Cytoskeletal motor proteins in Porphyra are restricted to a small set of kinesins that appear to be the only universal cytoskeletal motors within the red algae. Dynein motors are absent, and most red algae, including Porphyra, lack myosin. This surprisingly minimal cytoskeleton offers a potential explanation for why red algal cells and multicellular structures are more limited in size than in most multicellular lineages. Additional discoveries further relating to the stress tolerance of bangiophytes include ancestral enzymes for sulfation of the hydrophilic galactan-rich cell wall, evidence for mannan synthesis that originated before the divergence of green and red algae, and a high capacity for nutrient uptake. Our analyses provide a comprehensive understanding of the red algae, which are both commercially important and have played a major role in the evolution of other algal groups through secondary endosymbioses.
porphyra Bangiophyceae transcriptomes provide insights into red algal development and metabolismJournal of Phycology, 2012Co-Authors: Cheong Xin Chan, Charles Yarish, Simone Zäuner, Simon Prochnik, Nicolas A. Blouin, Yunyun Zhuang, Christoph Benning, Erika Lindquist, Martin Lohr, Elisabeth GanttAbstract:
The red seaweed Porphyra (Bangiophyceae) and related Bangiales have global economic importance. Here, we report the analysis of a comprehensive transcriptome comprising ca. 4.7 million expressed sequence tag (EST) reads from P. umbilicalis (L.) J. Agardh and P. purpurea (Roth) C. Agardh (ca. 980 Mbp of data generated using 454 FLX pyrosequencing). These ESTs were isolated from the haploid gametophyte (blades from both species) and diploid conchocelis stage (from P. purpurea). In a bioinformatic analysis, only 20% of the contigs were found to encode proteins of known biological function. Comparative analysis of predicted protein functions in mesophilic (including Porphyra) and extremophilic red algae suggest that the former has more putative functions related to signaling, membrane transport processes, and establishment of protein complexes. These enhanced functions may reflect general mesophilic adaptations. A near-complete repertoire of genes encoding histones and ribosomal proteins was identified, with some differentially regulated between the blade and conchocelis stage in P. purpurea. This finding may reflect specific regulatory processes associated with these distinct phases of the life history. Fatty acid desaturation patterns, in combination with gene expression profiles, demonstrate differences from seed plants with respect to the transport of fatty acid/lipid among subcellular compartments and the molecular machinery of lipid assembly. We also recovered a near-complete gene repertoire for enzymes involved in the formation of sterols and carotenoids, including candidate genes for the biosynthesis of lutein. Our findings provide key insights into the evolution, development, and biology of Porphyra, an important lineage of red algae.
Fungyi Chow – One of the best experts on this subject based on the ideXlab platform.
ecophysiological characteristics of porphyra spp Bangiophyceae rhodophyta seasonal and latitudinal variations in northern central chileJournal of Applied Phycology, 2014Co-Authors: F Tala, Fungyi ChowAbstract:
The red macroalga Porphyra C. Agardh is one of the most ecologically successful genera that lives in the upper intertidal zone. Biochemical, physiological, and morphological acclimation strategies allow their growth and distribution as well as a quick recuperation between tidal regimens. Studies of Porphyra are poorly developed in Chile, and management and exploitation proposals need to be supported by biological and ecophysiological approaches. This study evaluated seasonal and latitudinal physiological performances of Porphyra spp. via maximum quantum yield (Fv / Fm), pigments, proteins, phenolic compounds, and antioxidant activity in order to describe how algae can acclimate to their environment and to provide insights to their management and use. Sampling was done at three costal sites in Chile between 25°S and 34°S between winters 2010 and 2011. A total of four different morphotypes were identified (one in the north, one in the center, and two in the south locations) and evaluated separately. Results showed seasonal and latitudinal patterns for all ecophysiological variables studied, with a general tendency of decrease in Fv / Fm, pigments, and soluble proteins during spring–summer seasons accompanied by an increase in the antioxidant capacity. Latitudinal differences were observed with a tendency of higher values for ecophysiological traits in central and southern morphotypes. Phenology patterns were different between an annual population in the north location and a perennial one for central-south populations. The taxonomic clarity should be evaluated in order to better understand if there exists intraspecific (dependent on morphology) or interspecific variation.
phenology and photosynthetic performance of porphyra spp Bangiophyceae rhodophyta seasonal and latitudinal variation in chileAquatic Botany, 2014Co-Authors: F Tala, Fungyi ChowAbstract:
Abstract Phenological studies attempt to understand the seasonal development of organisms in response to environmental variations. Seaweeds can respond (1) as a “seasonal anticipator” with growth occurring due to specific triggers and (2) as a “seasonal responder”, with growth and photosynthesis occurring during more favorable conditions. Porphyra C. Agardh is an ecophysiologically successful genus that occurs in the uppermost rocky intertidal zone due to its biochemical and physiological traits. In Chile, Porphyra is distributed throughout all rocky shores (20–56° S), with at least five types of morphological strains and a still unclear taxonomic status. The phenology (cover, biomass, reproductive porcentage) and photosynthetic performance (ETR–light curves) were studied along a seasonal (winter 2010–winter 2011) and latitudinal gradient (25–34° S) in order to characterize the populations and promote their utilization for human food. Four different morphotypes were detected within the studied populations. Seasonal and latitudinal variations of the environment determined the phenological and ecophysiological responses of Porphyra spp. A decline in algal abundance, reproductive potential and photosynthetic performance during warm periods and from southern toward northern latitudes was observed. In a seasonal context, variation in temperature and irradiance can be crucial for the phenological and ecophysiological responses of Porphyra , whereas in a latitudinal context, temperature appeared to be more relevant. Most of the patterns observed, probably occurred due to biochemical and physiological traits. Studies on a seasonal and latitudinal scale might enhance the management and use of Porphyra as human food.
Francesco Cinelli – One of the best experts on this subject based on the ideXlab platform.
benthic marine flora in the tuscan archipelago a second contribution isle of gorgonaPlant Biosystems, 1993Co-Authors: Giorgio Pardi, Ilaria Papi, Luigi Piazzi, Francesco CinelliAbstract:
Abstract The benthic marine flora from the Isle of Gorgona has been studied. This paper is a compendium of new and already published data, in which 173 taxa of algae are listed: 3 Bangiophyceae, 116 Florideophyceae, 27 Phaeophyceae, 2 Chlorophyceae and 25 Bryopsidophyceae.
benthic marine flora in the tuscan archipelago a first contribution isles of capraia elba formiche di grosseto giglio scoglio d africa montecristo and giannutriPlant Biosystems, 1992Co-Authors: Ilaria Papi, Giorgio Pardi, Silvia Lenzini, Lisandro Benedetti Cecchi, Francesco CinelliAbstract:
Abstract Benthic marine flora of Tuscan Archipelago has been studied. Several samples were collected along five islands and some rocks. This paper is a compendium of new and already published data, in which 267 species, varieties, forms and stadia of algae and seagrasses are listed: 5 Bangiophyceae, 182 Florideophyceae, 45 Phaeophyceae, 6 Chlorophyceae, 28 Bryopsidophyceae, 1 Angiospermae.