Allometric growth reflects different allocation patterns and relationships of different components or traits of a plant and is closely related to ecosystem carbon storage. As an introduced species, the growth and carbon storage of Sonneratia apetala are still unclear. To derive allometric relationships of the mangrove S. apetala and to estimate carbon storage in mangrove ecosystems, we harvested 12 individual Sonneratia apetala trees from four different diameter classes in the Futian National Nature Reserve, Guangdong, China. Allometric growth models were fitted. The results showed that diameter at breast height (DBH) and wood density were better variables for predicting plant biomass (including above- and below-ground biomass) than plant height. There were significant power function relationships between biomass and DBH, with a mean allometric exponent of 2.22, and stem biomass accounted for 97% of the variation in S. apetala total biomass. Nearly isometric scaling relationships were developed between stem biomass and other biomass components. To better understand the carbon stocks of the S. apetala ecosystem, we categorized all trees into five age classes and quantified vegetation carbon storage. The S. apetala vegetation carbon storage ranged from 96.48 to 215.35 Mg C ha?1, and the carbon storage significantly increased with stand age. The allometric equations developed in this study are useful to estimate biomass and carbon storage of S. apetala ecosystems.
Self-assembly reaction of Cd(ClO4)2 · 6H2O with Norfloxacin (H-Norf) affords a novel 2D rectangular grid framework [Cd(Norf)(ClO4)(H2O)] (1) with strong blue luminescent emission (λem=425 nm), while Norf− acts as a tetradentate bridging linker to connect three Cd centers and ClO4 − completes Cd center octahedron coordination geometry. The compound 1 has crystallographic data of triclinic, space group , a=9.4577(1) Å, b=9.5012(2) Å, c=12.2805(1) Å, V=3624.4(3) Å3, Z=2. 相似文献
A high-quality reference genome is necessary to determine the molecular mechanisms underlying important biological phenomena; therefore, in the present study, a chromosome-level genome assembly of the Chinese shrimp Fenneropenaeus chinensis was performed. Muscle of a male shrimp was sequenced using PacBio platform, and assembled by Hi-C technology. The assembled F. chinensis genome was 1.47 Gb with contig N50 of 472.84 Kb, including 57.73% repetitive sequences, and was anchored to 43 pseudochromosomes, with scaffold N50 of 36.87 Mb. In total, 25,026 protein-coding genes were predicted. The genome size of F. chinensis showed significant contraction in comparison with that of other penaeid species, which is likely related to migration observed in this species. However, the F. chinensis genome included several expanded gene families related to cellular processes and metabolic processes, and the contracted gene families were associated with virus infection process. The findings signify the adaptation of F. chinensis to the selection pressure of migration and cold environment. Furthermore, the selection signature analysis identified genes associated with metabolism, phototransduction, and nervous system in cultured shrimps when compared with wild population, indicating targeted, artificial selection of growth, vision, and behavior during domestication. The construction of the genome of F. chinensis provided valuable information for the further genetic mechanism analysis of important biological processes, and will facilitate the research of genetic changes during evolution. 相似文献
Lipid peroxide (LPO) in lymphocytes from mice was evaluated by measuring substances reactive to thiobarbituric acid (TBA).
The product resulting from the reaction of TBA with lymphocytes was extracted with n-butyl and fluorescence intensity was
determined. The degree of lipid peroxidation, expressed as fluorescence intensity f547, was assessed for stimulation of lymphocytes
with concanavalin A (Con A), and was related to lymphocyte proliferation in response to Con A if Se was administered. The
lymphocyte proliferation was determined by [3H]thymidine incorporation, expressed as cpm. The effect of superoxide dismutase (SOD), added to cell culture on lymphocyte
proliferation was also evaluated. It was found that LPO in lymphocytes before Con A stimulation was significantly less than
that after stimulation (p<0.001), and that SOD promoted lymphocyte proliferation dose dependently. The addition of Na2SeO3 to lymphocyte culture or supplementation in drinking water to mice decreased the produced LPO in lymphocyte in response to
Con A. In the presence of Se, there is an inverse correlation between the levels of LPO in lymphocyte and the stimulated proliferation
(r=−0.8902,r=−0.9439). In conclusion, active oxygen species scavenging was proposed as one of the mechanisms for Se to promote immunity. 相似文献
Ricin is a potent ribosome inactivating protein and now has been widely used for synthesis of immunotoxins. To target ribosome in the mammalian cytosol, ricin must firstly retrograde transport from the endomembrane system to reach the endoplasmic reticulum (ER) where the ricin A chain (RTA) is recognized by ER components that facilitate its membrane translocation to the cytosol. In the study, the fusion gene of enhanced green fluorescent protein (EGFP)-RTA was expressed with the pET-28a (+) system in Escherichia coli under the control of a T7 promoter. The fusion protein showed a green fluorescence. The recombinant protein can be purified by metal chelated affinity chromatography on a column of NTA. The rabbit anti-GFP antibody can recognize the fusion protein of EGFP-RTA just like the EGFP protein. The cytotoxicity of EGFP-RTA and RTA was evaluated by the MTT assay in HeLa and HEP-G2 cells following fluid-phase endocytosis. The fusion protein had a similar cytotoxicity of RTA. After endocytosis, the subcellular location of the fusion protein can be observed with the laser scanning confocal microscopy and the immuno-gold labeling Electro Microscopy. This study provided important evidence by a visualized way to prove that RTA does reach the endoplasmic reticulum. 相似文献