Search

Michelia compressa (Maxim.) Sarg. is one of the important timber trees in Taiwan province, P. R. China. Michelia 'Zhongshanhanxiao' is a group of variants found among the progeny of M. compressa that exhibit higher growth rates compared with normal individuals, with a significantly increased stem diameter and height, as well as enlarged leaves and flowers. However, the molecular mechanisms fostering the growth advantage and morphological variations are unknown and deserve further study. Through analysing the transcriptome, metabolome and physiological processes of leaves, we identified remarkable differences in gene expression and metabolic profiles between Michelia 'Zhongshanhanxiao' and both the maternal M. compressa and its normal progeny. These differences were widely associated with a plant–pathogen interaction, phenylpropanoid biosynthesis, cyanoamino acid metabolism, carbon fixation in photosynthetic organisms and plant hormone signal transduction. Additionally, physiological measurements showed that Michelia 'Zhongshanhanxiao' possesses stronger photosynthetic capacity and higher plant hormone content. These results suggest that the heterosis of Michelia 'Zhongshanhanxiao' is regulated by candidates related to cell division, resistance to pathogens and the accumulation of organic compounds. The findings of this study provide crucial information on the molecular mechanisms underlying the growth advantages conferred by heterosis in trees. [ABSTRACT FROM AUTHOR]

Shallow‐water hydrothermal plumes concomitantly host both photosynthetic and chemoautotrophic organisms in a single biotope. Yet, rate measurements to quantify the contributions of different autotrophic activity types are scarce. Herein, we measured the light and dark dissolved inorganic carbon (DIC) uptake rates in the plume water of the Kueishantao hydrothermal field using the 13C‐labeling approach. Seventy percent of the plume‐water samples had chemoautotrophy as the dominant mode of carbon fixation, with the dark DIC uptake rates (up to 18.6 mg C/m3/h) within the range of the primary production in productive inner‐shelf waters. When considered alongside the geochemical and microbiological observations, the rate data reveal the distribution of different trophic activities in the hydrothermal plume. The autotrophic activity at the initial phase of plume dispersal is low. This is explained by the short response time the chemoautotrophs have to the stimulation from vent‐fluid discharge, and the harmful effects of hydrothermal substances on phytoplankton. As plume dispersal and mixing continue, chemoautotrophic activities begin to rise and peak in waters that have low‐to‐moderate Si(OH)4 content. Toward the plume margin, chemoautotrophy declines to background levels, whereas photosynthesis by phytoplankton regains importance. Our results also provide preliminary indication to the loci of enhanced heterotrophy in the plume. Results of artificial mixing experiments suggest that previously formed plume water is the primary source of microbial inoculum for new plume water. This self‐inoculation mechanism, in combination with the intense DIC uptake, helps to sustain a distinct planktonic autotrophic community in this rapidly flushed hydrothermal plume. [ABSTRACT FROM AUTHOR]

Climate change and the depletion of fossil fuels are the biggest challenges that humanity faces today. Solar energy can be used to mitigate climate change and reduce the demand for fossil fuels. Therefore, governments in different countries have actively developed the solar energy industry as a renewable energy industry. Although China and Taiwan respectively occupy first and second place in the current global output of solar energy products, they face serious pressure in the international market. To measure the operating efficiency of solar energy companies in China and Taiwan, this study combines the Shephard distance function and stochastic frontier analysis incorporating environmental variables. The empirical results show that: (1) China has better labour efficiency, (2) Taiwan has better operating cost efficiency, (3) both regions have extremely poor expenditure efficiency on R&D and the R&D expenditure rate is low, (4) the larger a company's size, the higher the labour efficiency and cost efficiency, and (5) the prices of raw materials have a direct impact on operating costs. It is hoped that the results of this research can provide recommendations for and promote changes in the operating and management strategies of the solar energy industry, improving its operating efficiency. [ABSTRACT FROM AUTHOR]

Abstract: Baculogypsina sphaerulata (Parker and Jones, 1860) is a common large benthic foraminifer (LBF) and is an important calcifier in coral reef ecosystems. As there are concerns that global increasing temperatures may compromise the survival of this species, which forms a symbiotic relationship with the diatom Nitzschia sp., we investigated the response of the B. sphaerulata holobiont from the intertidal algal flats of Xiao Liu Chiu Island, Taiwan to heat shock. B. sphaerulata specimens were incubated at 26 (ambient), 28, 30, 32, or 34°C for 5h designed to simulate short pulses of elevated temperature that occur in situ from subaerial exposure at low tide. To assess the molecular-level response, we measured the expression of the ribulose 1-5-bisphosphate carboxylase/oxygenase (RuBisCO) protein in the diatom symbiont. There was a significant decrease in expression of this rate-limiting carbon fixation enzyme in B. sphaerulata holobionts incubated at 34°C/8°C above ambient (~50% decline relative to controls), but expression was resilient to levels of warming up to 6°C above ambient. This suggests that exposure to high temperatures occasionally experienced in nature may diminish the capacity for carbon fixation of the diatom symbiont. Given the importance of photosynthesis and carbon fixation in these marine calcifiers, these data suggest that climate-driven ocean warming may exert deleterious effects on the B. sphaerulata holobiont. [Copyright &y& Elsevier]

[Display omitted] • Nitrogen starvation condition enhanced glucose productivity to 31.5 ± 3.0 mg/L/h. • Monosaccharide production enhanced with the 17β-estradiol level of 5 mg/L. • Highest CO 2 fixation rate reached to 151.8 ± 6.6 mg/L/h. • 17β-estradiol will be converted into E1 in the biodegradation process. • Photodegradation of 17β-estradiol is not as high as the biodegradation. Thermosynechococcus sp. CL-1 (TCL-1), a thermophilic cyanobacterium from a hot spring in Taiwan, has been known of its efficiency in CO 2 fixation, byproducts production (pigments, macromolecules). This study observed the performance of TCL-1 in CO 2 fixation, estrogen degradation, and monosaccharide production under various levels of Dissolved Inorganic Nitrogen (DIN) and 17β-estradiol (E2) as nitrogen supply and estrogen addition. Under nitrogen starvation, TCL-1 performed similar results on CO 2 fixation rate and biomass production but enhanced the monosaccharide production compared to the cases of high nitrogen supply. The highest CO 2 fixation rate and glucose productivity reached to 151.8 ± 6.6 and 38.1 ± 0.9 mg/L/h, under DIN level of 0.58 mM and 0.5 mg/L E2. Adding E2 in the system did not inhibit the performance of TCL-1. During the cultivation, TCL-1 converted E2 into E1 and the biodegradation was the main path for estrogen degradation. Total E2 degradation reached to 69.4 ± 2.0%. [ABSTRACT FROM AUTHOR]

Metagenomics of marine sediments has uncovered a broad diversity of new uncultured taxa and provided insights into their metabolic capabilities. Here, we detected microbial lineages from a sediment core near the Jiulong methane reef of the northern South China Sea (at 1,100-m depth). Assembly and binning of the metagenomes resulted in 11 genomes (>85% complete) that represented nine distinct phyla, including candidate phyla TA06 and LCP-89, Lokiarchaeota , Heimdallarchaeota , and a newly described globally distributed phylum (B38). The genome of LCP-89 has pathways for nitrate, selenate, and sulfate reduction, suggesting that they may be involved in mediating these important processes. B38 are able to participate in the cycling of hydrogen and selenocompounds. Many of these uncultured microbes may also be capable of autotrophic CO 2 fixation, as exemplified by identification of the Wood-Ljungdahl (W-L) pathway. Genes encoding carbohydrate degradation, W-L pathway, Rnf-dependent energy conservation, and Ni/Fe hydrogenases were detected in the transcriptomes of these novel members. Characterization of these new lineages provides insight to the undescribed branches in the tree of life. IMPORTANCE Sedimentary microorganisms in the South China Sea (SCS) remain largely unknown due to the complexity of sediment communities impacted by continent rifting and extension. Distinct geochemical environments may breed special microbial communities including microbes that are still enigmatic. Functional inference of their metabolisms and transcriptional activity provides insight in the ecological roles and substrate-based interactivity of these uncultured Archaea and Bacteria These microorganisms play different roles in utilizing inorganic carbon and scavenging diverse organic compounds involved in the deep-sea carbon cycle. The genomes recovered here contributed undescribed species to the tree of life and laid the foundation for future study on these novel phyla persisting in marginal sediments of the SCS., (Copyright © 2019 American Society for Microbiology.)