Impacts of Environmental Changes on the Use of Cellular Storage Products in a Temperate Cnidarian-Dinoflagellate Symbiosis

<p>Members of the phylum Cnidaria, such as corals and sea anemones, often form mutualistic endosymbiotic relationships with photosynthetic dinoflagellates that are founded upon a reciprocal exchange of nutrients. In this exchange, the cnidarian host provides its symbionts with nutrients derived through respiration, heterotrophy, and the environment, while the symbionts provide their host with products of photosynthesis. The energy derived from this exchange is utilized for metabolism, growth, and reproduction; alternatively, it can be accumulated into storage bodies for use during nutritional shortages or stress. Cnidarian-algal symbioses can be found throughout the world and vary in their sensitivity to stress, with environmental changes playing a prominent role in inducing stress. Tropical cnidarian-dinoflagellate symbioses are particularly vulnerable to temperature change, with increases of just 1-2℃ above their upper thermal limit often resulting in bleaching (the breakdown of symbiosis via symbiont expulsion). In contrast, temperate cnidarian-dinoflagellate symbioses exhibit far greater tolerance to such environmental stressors, and are rarely seen to bleach in the field. It is unclear how temperate cnidarian-dinoflagellate symbioses achieve this resilience and stability. This thesis examines the effects of changes in temperature and irradiance on the content of energy-rich cellular storage products in the temperate sea anemone Anthopleura aureoradiata and its dinoflagellate endosymbionts (family: Symbiodiniaceae), in order to assess the potential of these compounds in contributing to the overall stability of the symbiosis. In particular, symbiont density and chlorophyll content (as well as photosynthetic efficiency, for experimental study only), in addition to both symbiont and host protein content, served as indicators of physiological health, and were then related to the accumulation of cellular storage products such as lipids and carbohydrates. A field study was conducted in which a population of A. aureoradiata was sampled from Wellington Harbor, New Zealand, at monthly intervals for one year. Despite monthly and seasonal variability in the physiological parameters measured, the symbiosis remained functional and stable (i.e. no signs of bleaching) throughout the year. The greatest inter-seasonal variation occurred in the symbiont cell-specific carbohydrate content, which decreased significantly between spring and summer. In contrast, host lipid content exhibited less variation than all other symbiont and host storage products. These observations suggest that symbiont carbohydrate stores are primarily utilized to sustain the symbiosis during times of seasonal environmental change (in this case, correlating with increased light and temperature during summer), while lipids may be kept in reserve. The robustness of this field population is expected; being a native species, A. aureoradiata is likely highly acclimated to the conditions that were observed throughout the year of this field study. A separate population of A. aureoradiata was subsequently acclimated to a moderate regime of temperature and irradiance, and then exposed to one of six treatments of different combined temperatures and irradiances (based on seasonal conditions in the Wellington Harbour), to establish their interactive effects on cellular storage product content. Specifically, three thermal regimes (low: 9±1°C, moderate: 14.5±1°C, high: 21±1°C), each at a low (70±10 µmol photons m-2 s-1) or high (145±15 µmol photons m-2 s-1) irradiance, were maintained for a total of sixteen weeks. Unlike in the field, a breakdown in symbiosis was observed; photo-physiological dysfunction of the symbiosis was observed within four weeks in all anemones exposed to low temperature at both irradiances, and bleaching was apparent by week eight. This response likely arose from a combination of the rapid decrease in temperature experienced upon distribution into the low-temperature tank, as well as the prolonged nature of the conditions in the experiment, which would not be experienced in the field. In contrast, the anemones maintained at both irradiances in the moderate and high temperature treatments maintained a stable symbiosis, suggesting that these conditions were not extreme enough to cause notable stress. In fact, anemones kept under both low and high irradiance within the moderate temperature treatment increased in symbiont density and exhibited the highest host lipid content relative to the other treatments, suggesting that this treatment was near-optimal for the symbiosis. Perhaps interestingly, both the moderate and high temperature treatments induced significant reductions in symbiont-specific protein, lipid, and carbohydrate content, while host storage products decreased less drastically. This observation suggests increased utilization of symbiont storage products to maintain a healthy symbiosis under these experimental conditions. My findings are consistent with previous reports of seasonal stability in temperate cnidarian-dinoflagellate symbioses; moreover, I provide experimental evidence for the utilization of symbiont storage products as a means of maintaining symbiosis stability, though this was less apparent in the field. Although recent studies have made great progress in identifying patterns of stability in temperate cnidarian-dinoflagellate symbioses, additional studies are required to build a more comprehensive picture of the mechanisms involved. Future studies would benefit from increased frequency of field sampling, including assessments of nutrient availability and host reproductive cycles, to better understand the monthly and seasonal variability in the intracellular storage product use observed in the field. Nevertheless, results of this study contribute to an improved understanding of the physiology and remarkable stability of temperate cnidarian-dinoflagellate symbioses, with implications for predictions of how they might respond to future climate change scenarios.</p>

Impacts of Environmental Changes on the Use of Cellular Storage Products in a Temperate Cnidarian-Dinoflagellate Symbiosis

<p>Members of the phylum Cnidaria, such as corals and sea anemones, often form mutualistic endosymbiotic relationships with photosynthetic dinoflagellates that are founded upon a reciprocal exchange of nutrients. In this exchange, the cnidarian host provides its symbionts with nutrients derived through respiration, heterotrophy, and the environment, while the symbionts provide their host with products of photosynthesis. The energy derived from this exchange is utilized for metabolism, growth, and reproduction; alternatively, it can be accumulated into storage bodies for use during nutritional shortages or stress. Cnidarian-algal symbioses can be found throughout the world and vary in their sensitivity to stress, with environmental changes playing a prominent role in inducing stress. Tropical cnidarian-dinoflagellate symbioses are particularly vulnerable to temperature change, with increases of just 1-2℃ above their upper thermal limit often resulting in bleaching (the breakdown of symbiosis via symbiont expulsion). In contrast, temperate cnidarian-dinoflagellate symbioses exhibit far greater tolerance to such environmental stressors, and are rarely seen to bleach in the field. It is unclear how temperate cnidarian-dinoflagellate symbioses achieve this resilience and stability. This thesis examines the effects of changes in temperature and irradiance on the content of energy-rich cellular storage products in the temperate sea anemone Anthopleura aureoradiata and its dinoflagellate endosymbionts (family: Symbiodiniaceae), in order to assess the potential of these compounds in contributing to the overall stability of the symbiosis. In particular, symbiont density and chlorophyll content (as well as photosynthetic efficiency, for experimental study only), in addition to both symbiont and host protein content, served as indicators of physiological health, and were then related to the accumulation of cellular storage products such as lipids and carbohydrates. A field study was conducted in which a population of A. aureoradiata was sampled from Wellington Harbor, New Zealand, at monthly intervals for one year. Despite monthly and seasonal variability in the physiological parameters measured, the symbiosis remained functional and stable (i.e. no signs of bleaching) throughout the year. The greatest inter-seasonal variation occurred in the symbiont cell-specific carbohydrate content, which decreased significantly between spring and summer. In contrast, host lipid content exhibited less variation than all other symbiont and host storage products. These observations suggest that symbiont carbohydrate stores are primarily utilized to sustain the symbiosis during times of seasonal environmental change (in this case, correlating with increased light and temperature during summer), while lipids may be kept in reserve. The robustness of this field population is expected; being a native species, A. aureoradiata is likely highly acclimated to the conditions that were observed throughout the year of this field study. A separate population of A. aureoradiata was subsequently acclimated to a moderate regime of temperature and irradiance, and then exposed to one of six treatments of different combined temperatures and irradiances (based on seasonal conditions in the Wellington Harbour), to establish their interactive effects on cellular storage product content. Specifically, three thermal regimes (low: 9±1°C, moderate: 14.5±1°C, high: 21±1°C), each at a low (70±10 µmol photons m-2 s-1) or high (145±15 µmol photons m-2 s-1) irradiance, were maintained for a total of sixteen weeks. Unlike in the field, a breakdown in symbiosis was observed; photo-physiological dysfunction of the symbiosis was observed within four weeks in all anemones exposed to low temperature at both irradiances, and bleaching was apparent by week eight. This response likely arose from a combination of the rapid decrease in temperature experienced upon distribution into the low-temperature tank, as well as the prolonged nature of the conditions in the experiment, which would not be experienced in the field. In contrast, the anemones maintained at both irradiances in the moderate and high temperature treatments maintained a stable symbiosis, suggesting that these conditions were not extreme enough to cause notable stress. In fact, anemones kept under both low and high irradiance within the moderate temperature treatment increased in symbiont density and exhibited the highest host lipid content relative to the other treatments, suggesting that this treatment was near-optimal for the symbiosis. Perhaps interestingly, both the moderate and high temperature treatments induced significant reductions in symbiont-specific protein, lipid, and carbohydrate content, while host storage products decreased less drastically. This observation suggests increased utilization of symbiont storage products to maintain a healthy symbiosis under these experimental conditions. My findings are consistent with previous reports of seasonal stability in temperate cnidarian-dinoflagellate symbioses; moreover, I provide experimental evidence for the utilization of symbiont storage products as a means of maintaining symbiosis stability, though this was less apparent in the field. Although recent studies have made great progress in identifying patterns of stability in temperate cnidarian-dinoflagellate symbioses, additional studies are required to build a more comprehensive picture of the mechanisms involved. Future studies would benefit from increased frequency of field sampling, including assessments of nutrient availability and host reproductive cycles, to better understand the monthly and seasonal variability in the intracellular storage product use observed in the field. Nevertheless, results of this study contribute to an improved understanding of the physiology and remarkable stability of temperate cnidarian-dinoflagellate symbioses, with implications for predictions of how they might respond to future climate change scenarios.</p>

Crosstalk during the Carbon–Nitrogen Cycle That Interlinks the Biosynthesis, Mobilization and Accumulation of Seed Storage Reserves

Carbohydrates are the major storage reserves in seeds, and they are produced and accumulated in specific tissues during the growth and development of a plant. The storage products are hydrolyzed into a mobile form, and they are then translocated to the developing tissue following seed germination, thereby ensuring new plant formation and seedling vigor. The utilization of seed reserves is an important characteristic of seed quality. This review focuses on the seed storage reserve composition, source–sink relations and partitioning of the major transported carbohydrate form, i.e., sucrose, into different reserves through sucrolytic processes, biosynthetic pathways, interchanging levels during mobilization and crosstalk based on vital biochemical pathways that interlink the carbon and nitrogen cycles. Seed storage reserves are important due to their nutritional value; therefore, novel approaches to augmenting the targeted storage reserve are also discussed.

Inflammatory arthritis complicating galactosialidosis: a case report

Background Galactosialidosis (GS) is a rare inherited lysosomal storage disorder (LSD) which is characterized by a defect in the lysosomal glycoprotein catabolism. We report, for the first time, the case of a child affected by GS presenting with recurrent episodes of extensive joint inflammation in both knee joints. The aim of this case-report is to describe the clinical presentation as well as the laboratory, radiologic and microscopic features of this unique presentation of GS. Furthermore, we explore inflammatory mechanisms potentially responsible for the origination of the arthritic joint pathology observed in our patient. Case presentation We describe the rare case of a 12-year-old boy diagnosed with GS (late infantile form) who presented with multiple episodes of inflammatory arthritis involving both knees; no other joints were suspected for joint inflammation. Laboratory results did not indicate an autoimmune disorder. Synovial fluid tested negative for any bacterial infection and ruled out a malignancy and crystal-induced arthritis. Microscopic examination of the synovial tissue revealed numerous foamy macrophages with extensive vacuolization, consistent with the previous diagnosis of GS. Treatment consisted of aspiration of excessive joint fluid and subsequent intra-articular injection of triamcinolonhexacetonide with excellent but transient result. Given the evidence of storage products within macrophages of the inflamed synovial tissue and the absence of other etiological clues, GS itself was considered as the primary cause for the relapsing inflammatory joint pathology. According to the restricted data on articular manifestations in GS, to date, GS cannot be linked directly to joint inflammation. Nevertheless, in several other LSDs, the accumulation of storage material has been associated with numerous osteoimmunological changes that might play a role in the pathophysiology of arthritic processes. Conclusions We hypothesize that the articular build-up of GS storage products triggered systemic as well as local inflammatory processes, resulting in the extensive inflammatory joint pathology as observed in our patient. Future identification of other patients with GS is required to corroborate the existence of an arthritic clinical phenotype of GS and to assess the underlying pathophysiology.

Inventory of tools and products for the storage and conservation of Bambara (Vigna subterranea (L) Verdcourt) seeds as a means of prevention against bruchis in Niger

In Niger, several types of tools and products are used for the storage of Bambara groundnut. The objective of this study was to identify the tools and products used to prevent the damage of Callosobruchus maculatus (Fab.) On Bambara groundnut seeds in storage. Structured sowing questionnaires were administered to 404 heads of households in 16 target villages. Thus, some of the data collected was compared with means using analysis of variance (ANOVA) at a significance level of 5% followed by Ducan's test. Other results were used to make tables and figures using Excel software. It emerges from this survey that the seed is the most used form in the storage of Bambara groundnut (95%). The study revealed a diversity of tools encountered depending on the region. Single cans are used more in Tillabéri (70.4%) compared to Maradi (21.1%) and Dosso (15.3%). PICS bags are only used in Maradi (35.8%) and Dosso (35.3%). It was also observed that the simple bags are more encountered in Maradi (36.8%) followed by Dosso (8.6%) and Tillabéri (1.9%). Bank Grainary made of mud are only encountered in Dosso (37.3%). The inert storage products are the fine sand used in Dosso (37%), Tillabéri (13%), Maradi (4%) and the ash found only in Maradi (2%). At the same time, producers are increasingly adopting very toxic chemicals such as Phostoxin, Superdelvap to the detriment of local (Traditional) products. Au Niger, plusieurs types d’outils et produits sont utilisés pour le stockage de Voandzou. L’objectif de cette étude était d’inventorier les outils et produits utilisés pour prévenir les dégâts du Callosobruchus maculatus (Fab.) sur les graines de Voandzou en stockage. Des questionnaires semis structurés ont été administrés auprès de 404 chefs de ménages dans 16 villages cibles. Ainsi, certaines données recueillies ont fait l’objet d’une comparaison des moyennes en utilisant une analyse de la variance (ANOVA) à un niveau de signification de 5% suivie du test de Ducan. D’autres résultats ont servi de faire les tableaux et figures grâce au logiciel Excel. Il ressort de cette enquête que la graine est la forme la plus utilisée dans le stockage de Voandzou (95%). L’étude a ressorti une diversité d’outils rencontrés selon les régions. Les bidons simples sont plus utilisés à Tillabéri (70,4%) comparativement à Maradi (21,1%) et Dosso (15,3%). Les sacs PICS sont seulement utilisés à Maradi (35,8%) et Dosso (35,3%). Il a été aussi observé que les sacs simples sont plus rencontrés à Maradi (36,8%) suivi de Dosso (8,6%) et Tillabéri (1,9%). Les Greniers en bancos ne sont rencontrés qu’à Dosso (37,3%). Les produits inertes de stockage sont le sable fin utilisé à Dosso (37%), Tillabéri (13%), Maradi (4%) et la cendre rencontrée seulement à Maradi (2%). Dans le même temps, les producteurs adoptent de plus en plus des produits chimiques très toxiques comme le Phostoxin, le Superdelvap au détriment des produits locaux (Traditionnels).

Pigment and Fatty Acid Production under Different Light Qualities in the Diatom Phaeodactylum tricornutum

Diatoms are microscopic biorefineries producing value-added molecules, including unique pigments, triglycerides (TAGs) and long-chain polyunsaturated fatty acids (LC-PUFAs), with potential implications in aquaculture feeding and the food or biofuel industries. These molecules are utilized in vivo for energy harvesting from sunlight to drive photosynthesis and as photosynthetic storage products, respectively. In the present paper, we evaluate the effect of narrow-band spectral illumination on carotenoid, LC-PUFAs and TAG contents in the model diatom Phaeodactylum tricornutum. Shorter wavelengths in the blue spectral range resulted in higher production of total fatty acids, namely saturated TAGs. Longer wavelengths in the red spectral range increased the cell’s content in Hexadecatrienoic acid (HTA) and Eicosapentaenoic acid (EPA). Red wavelengths induced higher production of photoprotective carotenoids, namely fucoxanthin. In combination, the results demonstrate how diatom value-added molecule production can be modulated by spectral light control during the growth. How diatoms could use such mechanisms to regulate efficient light absorption and cell buoyancy in the open ocean is discussed.

Thermal effect on pseudocapacitive behavior of high-performance flexible supercapacitors based on polypyrrole-decorated carbon cloth electrodes

With the ongoing advance of flexible energy storage products for commercial portable electronics application, the fundamental comprehension of the temperature dependence for supercapacitors is in urgent demand. Although polypyrrole (PPy)...

Inflammatory Arthritis Complicating Galactosialidosis: A Case Report

Background Galactosialidosis (GS) is a rare inherited lysosomal storage disorder (LSD) which is characterized by a defect in the lysosomal glycoprotein catabolism. We report, for the first time, the case of a child affected by GS presenting with recurrent episodes of extensive joint inflammation in both knee joints. The aim of this case-report is to describe the clinical presentation as well as the laboratory, radiologic and microscopic features of this unique presentation of GS. Furthermore, we explore inflammatory mechanisms potentially responsible for the origination of the arthritic joint pathology observed in our patient.Case presentationWe describe the rare case of a 12-year-old boy diagnosed with GS (late infantile form) who presented with multiple episodes of inflammatory arthritis involving both knees; no other joints were suspected for joint inflammation. Laboratory results did not indicate an autoimmune disorder. Synovial fluid tested negative for any bacterial infection and ruled out a malignancy and crystal induced arthritis. Microscopic examination of the synovial tissue revealed numerous foamy macrophages with extensive vacuolization, consistent with the previous diagnosis of GS. Treatment consisted of aspiration of excessive joint fluid and subsequent intra-articular injection of triamcinolonhexacetonide with excellent but transient result. Given the evidence of storage products within macrophages of the inflamed synovial tissue and the absence of other etiological clues, GS itself was considered as the primary cause for the relapsing inflammatory joint pathology. According to the restricted data on articular manifestations in GS, to date, GS cannot be linked directly to joint inflammation. Nevertheless, in several other LSDs, the accumulation of storage material has been associated with numerous osteoimmunological changes that might play a role in the pathophysiology of arthritic processes. Conclusions We hypothesize that the articular build-up of GS storage products triggered systemic as well as local inflammatory processes, resulting in the extensive inflammatory joint pathology as observed in our patient. Future identification of other patients with GS is required to corroborate the existence of an arthritic clinical phenotype of GS and to assess the underlying pathophysiology.