Effect of temperature on betacyanins synthesis and the transcriptome of Suaeda salsa

IntroductionSuaeda salsa (Linn.) Pall. is an important tourist resource and ecological restoration species in coastal wetlands. Environmental factors such as low temperature, darkness, phytohormone, salt stress and seawater flflooding, and light can induce betalain synthesis in S. salsa, which plays an important role in plant adaptation to abiotic stress processes and in shaping the beautiful “red beach” landscape.MethodsIn this study, Illumina sequencing was used to profifile the transcriptome sequence (RNA-Seq) of S. salsa leaves at different temperatures (5° C, 10°C, 15°C, 20°C, 25°C, and 30°C) and to validate differentially expressed genes (DEGs) indicated by real-time PCR (RT-qPCR).ResultsThe betacyanin content was highest in S. salsa leaves at 15°C. Transcription group data showed that compared to the control group (15°C), the “betacyanin biosynthesis pathway” was signifificantly enriched in the fifive different temperature groups. KEGG analysis showed that the DEGs were mainly involved in pathways of phenylpropanoid biosynthesis, carbon fifixation in photosynthetic organisms, flflavonoid biosynthesis, and betacyanin biosynthesis. Among the key enzymes involved in biosynthesis of betacyanin, genes for tyrosinase, CYP76AD1 and 4,5-DOPA dioxygenase were signifificantly upregulated and most abundantly expressed at 15°C. It is possible that the gene for betacyanin synthesis from S. salsa is primarily regulated by the MYB1R1 and MYB1 transcription factor. Four DEGs were randomly selected for quantitative PCR analysis, and DEG expression was generally consistent with the RNA-Seq data, verifying the validity of the transcriptome sequencing data.DiscussionRelative to other temperatures, 15°C was optimum for S. salsa betacyanin synthesis, and this provides a theoretical reference for coastal wetland ecological remediation, reveals mechanisms of S. salsa discoloration, and further mines its potential application for landscape vegetation

The world's largest macroalgal bloom in the Yellow Sea, China: Formation and implications

The world's largest trans-regional macroalgal blooms during 2008-2012 occurred in the Yellow Sea, China. This review addresses the causes, development and future challenges in this unique case. Satellite imagery and field observations showed that the macroalgal blooms in the Yellow Sea originated from the coast of Jiangsu province and that favorable geographic and oceanographic conditions brought the green macroalgae from the coast offshore. Optimal temperature, light, nutrients and wind contributed to the formation and transport of the massive bloom north into the Yellow Sea and its deposition onshore along the coast of Shandong province. Morphological and genetic evidence demonstrated that the species involved was Ulva prolifera, a fouling green commonly found growing on structures provided by facilities of Porphyra aquaculture. Large scale Porphyra aquaculture (covering >20,000 ha) along the Jiangsu coast thus hypothetically provided a nursery bed for the original biomass of U. prolifera. Porphyra growers remove U. prolifera from the mariculture rafts, and the cleaning releases about 5000 wet weight tonnes of green algae into the water column along the coast of Jiangsu province; the biomass then is dispersed by hydrographic forcing, and takes advantage of rather high nutrient supply and suitable temperatures to grow to impressive levels. Certain biological traits of U. prolifera -efficient photosynthesis, rapid growth rates, high capacity for nutrient uptake, and diverse reproductive systems- allowed growth of the original 5000 tonnes of U. prolifera biomass into more than one million tonnes of biomass in just two months. The proliferation of U. prolifera in the Yellow Sea resulted from a complex contingency of circumstances, including human activity (eutrophication by release of nutrients from wastewater, agriculture, and aquaculture), natural geographic and hydrodynamic conditions (current, wind) and the key organism's biological attributes. Better understanding of the complex biological-chemical-physical interactions in coastal ecosystems and the development of an effective integrated coastal zone management with consideration of scientific, social and political implications are critical to solving the conflicts between human activity and nature. (c) 2013 Elsevier Ltd. All rights reserved.The world's largest trans-regional macroalgal blooms during 2008-2012 occurred in the Yellow Sea, China. This review addresses the causes, development and future challenges in this unique case. Satellite imagery and field observations showed that the macroalgal blooms in the Yellow Sea originated from the coast of Jiangsu province and that favorable geographic and oceanographic conditions brought the green macroalgae from the coast offshore. Optimal temperature, light, nutrients and wind contributed to the formation and transport of the massive bloom north into the Yellow Sea and its deposition onshore along the coast of Shandong province. Morphological and genetic evidence demonstrated that the species involved was Ulva prolifera, a fouling green commonly found growing on structures provided by facilities of Porphyra aquaculture. Large scale Porphyra aquaculture (covering >20,000 ha) along the Jiangsu coast thus hypothetically provided a nursery bed for the original biomass of U. prolifera. Porphyra growers remove U. prolifera from the mariculture rafts, and the cleaning releases about 5000 wet weight tonnes of green algae into the water column along the coast of Jiangsu province; the biomass then is dispersed by hydrographic forcing, and takes advantage of rather high nutrient supply and suitable temperatures to grow to impressive levels. Certain biological traits of U. prolifera -efficient photosynthesis, rapid growth rates, high capacity for nutrient uptake, and diverse reproductive systems- allowed growth of the original 5000 tonnes of U. prolifera biomass into more than one million tonnes of biomass in just two months. The proliferation of U. prolifera in the Yellow Sea resulted from a complex contingency of circumstances, including human activity (eutrophication by release of nutrients from wastewater, agriculture, and aquaculture), natural geographic and hydrodynamic conditions (current, wind) and the key organism's biological attributes. Better understanding of the complex biological-chemical-physical interactions in coastal ecosystems and the development of an effective integrated coastal zone management with consideration of scientific, social and political implications are critical to solving the conflicts between human activity and nature. (c) 2013 Elsevier Ltd. All rights reserved

The adaptation of Arctic phytoplankton to low light and salinity in Kongsfjorden (Spitsbergen)

The basic environmental variables and adaptability of phytoplankton communities to low light and salinity were studied using incubation experiments in Kongsfjorden, a high Arctic fjord of Spitsbergen, in late summer 2006. Chlorophyll a concentrations were steady or decreased slightly in darkness after one day or one week incubation. Chlorophyll a concentrations showed an initial decline when exposed to natural light after one week incubation in darkness, and then increased significantly. In a salinity experiment, the maximal growth rate was observed at a dilution ratio of 10%, however, higher dilution ratios (≥40%) had an obvious negative effect on phytoplankton growth. We suggest that the phytoplankton communities in fjords in late summer are darkness adapted, and the inflow of glacial melt water is favorable for phytoplankton growth in the outer fjords where the influence of freshwater is limited

Spatiotemporal Dynamic of Ostreococcus lucimarinus in IMTA System at Enclosed Sea (Hangzhou Bay) East China Sea Using Environmental DNA (eDNA)

Integrated Multi-Trophic Aquaculture (IMTA) is growing fast in China, in order for cultivation with this system to continue. Through eDNA approach in able to detect Ostreococcus lucimarinus which include picoeukaryotic in IMTA system at enclosed sea (Hangzhou Bay). Information about this species and their ecological placement in the IMTA system is still very limited. eDNA is an ecological approach that can detect supply down to the species level in monitoring aquatic ecology in the IMTA system. The purpose of this study was to determine the taxonomy and guarantees of Ostreococcus lucimarinus and the role of this species in the IMTA system descriptively. Through high throughput sequencing, the taxonomic results of Ostreococcus lucimarinus and confinement of this picoekaryotic species were highest in winter with a total of 599,632 ind. Based on the sampling location, the highest abundance were in aquaculture areas of 337,165 ind. The approach using eDNA has proven to be capable of detecting up to the species level as well as spatiotemporal abundance dynamics of Ostreococcus lucimarinus

Optimal Investment Strategy under the CEV Model with Stochastic Interest Rate

Interest rate is an important macrofactor that affects asset prices in the financial market. As the interest rate in the real market has the property of fluctuation, it might lead to a great bias in asset allocation if we only view the interest rate as a constant in portfolio management. In this paper, we mainly study an optimal investment strategy problem by employing a constant elasticity of variance (CEV) process and stochastic interest rate. The assets of investment for individuals are supposed to be composed of one risk-free asset and one risky asset. The interest rate for risk-free asset is assumed to follow the Cox–Ingersoll–Ross (CIR) process, and the price of risky asset follows the CEV process. The objective is to maximize the expected utility of terminal wealth. By applying the dual method, Legendre transformation, and asymptotic expansion approach, we successfully obtain an asymptotic solution for the optimal investment strategy under constant absolute risk aversion (CARA) utility function. In the end, some numerical examples are provided to support our theoretical results and to illustrate the effect of stochastic interest rates and some other model parameters on the optimal investment strategy

Effect of different temperature fluctuations and different initial concentrations of NO₃-N and PO₄-P on growth, nutrient uptake and photosynthetic efficiency of <i>Gracilaria asiatica</i>

1128-1134The effects of three temperature fluctuations combined with different initial NO3-N and PO4-P concentrations on growth rate, nutrient uptake as well as photosynthetic efficiency were assessed. Gracilaria asiatica were collected from the coast of Fujian, China for this present study. Study revealed that after 15 days, the highest growth rate of G. asiatica was recorded at 20ºC under low initial nutrient concentration whiles the lowest was recorded at 25ºC under high initial nutrient concentration. The NO3-N uptake rate of G. asiatica under low and high initial concentration at temperatures 20ºC and 20±2ºC were higher than other conditions after 15 days. On the other hand the PO3-P uptake rate under high initial concentration at temperatures 20ºC and 20±2ºC were lower than other conditions after 15 days. After the third day, NO3-N and PO4-P were exhausted from the medium when the initial concentration were low under different temperature fluctuations. Photosynthetic efficiency observed at temperatures 15ºC and 15±2ºC decreased from beginning whiles the photosynthetic efficiency at 25ºC and 25±2ºC increased from beginning. We concluded that temperature fluctuations integrated with different initial NO3-N and PO4-P concentrations affects growth rate, nutrient uptake as well as photosynthetic efficiency of G. asiatica

<i style="mso-bidi-font-style:normal"><span style="font-size:11.0pt;font-family:"Times New Roman";mso-fareast-font-family: "Times New Roman";mso-bidi-font-family:Mangal;mso-ansi-language:EN-GB; mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB">Gracilariopsis longissima</span></i><span style="font-size:11.0pt;font-family:"Times New Roman";mso-fareast-font-family: "Times New Roman";mso-bidi-font-family:Mangal;mso-ansi-language:EN-GB; mso-fareast-language:EN-US;mso-bidi-language:HI" lang="EN-GB"> as biofilter for an Integrated Multi-Trophic aquaculture (IMTA) system with <i style="mso-bidi-font-style: normal">Sciaenops ocellatus</i>: Bioremediation efficiency and production in a recirculating system</span>

528-537A recirculating integrated system producing Sciaenops ocellatus and Gracilariopsis longissima (a red seaweed) was evaluated with respect to nutrient removal efficiency and production. G. longissima was found to be efficient in removing toxic ammonia and maintaining the water quality within an acceptable level for S. ocellatus culture. Specific growth rate (SGR) of S. ocellatus ranged from 0.064 ± 0.006% d-1 to 0.099% ± 0.010% d-1. Survival rates of S. ocellatus were 100% in the Integrated Multi-Trophic Aquaculture (IMTA) systems. <i style="mso-bidi-font-style: normal">G. longissima had average SGRs of 3.03 ± 0.11% d-1, 2.48 ± 0.04% d-1, 1.86 ± 0.26% d-1 and 1.12 ± 0.16% d-1 under initial densities of 1 g L-1, 3 g L-1, 6 g L-1 and 9 g L-1, respectively. Daily average nitrogen and phosphorus uptake rates of G. longissima were negatively correlated to cultivation densities in the recirculating system. Biofiltration capacity of G. longissima was confirmed by significantly reduced concentrations of ammonia, nitrate, nitrite and phosphate in the integrated system with S. ocellatus. Results indicated that G. longissima is suitable as a good candidate for IMTA systems