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91.
92.
Nannan Wang Lei Li Bingwei Zhang Shiping Chen Wei Sun Yukun Luo Kuanhu Dong Xingguo Han Jianhui Huang Xiaofeng Xu Changhui Wang 《Journal of Plant Ecology》2020,13(4):499
土壤中细菌和真菌的稳定性在维持土壤生态系统功能方面起着重要作用,环境条件的改变直接影响细菌和真菌的组成与结构。已有研究表明,土壤真菌群落稳定性对降水变化响应的敏感性比细菌低,但其内在机制还不清楚。在内蒙古典型草原建立3年的增减降雨实验平台,设置5个降水梯度,包括分别增加和减少30%和60%的降水量以及对照,比较控制不同的降水水平对土壤细菌和真菌多样性的影响,包括α多样性,β多样性和细菌/真菌群落组成的变化。本研究开发了一个概念模型来反映不同降水条件下土壤细菌和真菌的稳定性特征,其中模型山谷的深度表示微生物抵抗力(Resistance),谷的宽度代表生态弹性(Ecological Resilience)。结果表明,增加和减少60%的降水量均显著降低了细菌的丰富度,同时显著增加了细菌均匀度,但对真菌的丰富度和均匀度没有显著的影响。降水对细菌α多样性的影响高于真菌,说明细菌对水分胁迫的敏感性大于真菌。而真菌群落的周转比细菌快,包括组成变化(Composition Variation),多样性指数和变异系数(Coefficient Variation),反映了真菌群落具有较高的群落可变性,使得降水变化对真菌群落的影响较小。概念模型中两种相反的情景表示细菌和真菌对降水变化不同的响应模式:真菌群落对水分胁迫响应不敏感,可以用宽谷中的一个球来表示,球虽然在较大范围内往复摆动,但仍接近稳定状态;而细菌群落对水分响应敏感,即稳定性低,可以表示为一个球在较窄的谷里远离平衡态的位置摆动。基于本研究结果,半干旱草原真菌群落比细菌群落具有更高的稳定性,该结论对于量化群落稳定性特征具有重要意义。 相似文献
93.
Variations in the carbon isotope signature of leaf dark-respired CO2 (δ13CR) within a single night is a widely observed phenomenon. However, it is unclear whether there are plant functional type differences with regard to the amplitude of the nighttime variation in δ13CR. These differences, if present, would be important for interpreting the short-term variations in the stable carbon signature of ecosystem respiration and the partitioning of carbon fluxes. To assess the plant functional type differences relating to the magnitude of the nighttime variation in δ13CR and the respiratory apparent fractionation, we measured the δ13CR, the leaf gas exchange, and the δ13C of the respiratory substrates of 22 species present in the agricultural-pastoral zone of the Songnen Plain, northeast China. The species studied were grouped into C3 and C4 plants, trees, grasses, and herbs. A significant nocturnal shift in δ13CR was detected in 20 of the studied species, with the magnitude of the shift ranging from 1‰ to 5.8‰. The magnitude of the nighttime variation in δ13CR was strongly correlated with the daytime cumulative carbon assimilation, which suggests that variation in δ13CR were influenced, to some extent, by changes in the contribution of malate decarboxylation to total respiratory CO2 flux. There were no differences in the magnitude of the nighttime variation in δ13CR between the C3 and C4 plants, as well as among the woody plants, herbs and graminoids. Leaf respired CO2 was enriched in 13C compared to biomass, soluble carbohydrates and lipids; however the magnitude of enrichment differed between 8 pm and 4 am, which were mainly caused by the changes in δ13CR. We also detected the plant functional type differences in respiratory apparent fractionation relative to biomass at 4 am, which suggests that caution should be exercised when using the δ13C of bulk leaf material as a proxy for the δ13C of leaf-respired CO2. 相似文献
94.
Shiping Li Tao Xu Jin Zhou Zhou Jiang Wang Hou Junjie Ying 《Biological Rhythm Research》2015,46(4):565-572
Circadian locomotor output cycles kaput (Clock) gene is a core gene in the circadian rhythm system that is involved in cancer cell proliferation. However, the molecular mechanism of Clock gene participate in the cancer cell proliferation is unclear. Previous studies demonstrated that cell proliferation could be regulated by the canonical Wnt pathway (also known as the Wnt/β-catenin pathway), and the Wnt/β-catenin pathway had a relation with the circadian system. To investigate whether the Clock gene affects the proliferation of breast cancer cell by regulating the expression of β-catenin, we knocked down the Clock expression of mouse breast cancer cells (4T1) by RNA interference. Then detected their proliferation rates using CCK8 assay and the expression of the β-catenin gene by real-time PCR and Western blot. The results showed that the proliferation of the Clock knocked down 4T1 cells is slower than the control. The expression level of β-catenin of these 4T1 cells is reduced. Our study showed that Clock gene knocked down inhibiting the proliferation of the 4T1 cells, probably by suppressing the expression of β-catenin. 相似文献
95.
Aims
A new liquid-phase piezoelectric immunosensor (LP-PEIS), which can detect Schistosoma japonicum (Sj) circulating antigens (SjCAg) quantificationally, was developed.Methods
The IgG antibodies were purified from the sera of rabbits which had been infected or immunized by Sj and were immobilized on the surface of piezoelectric quartz crystal in LP-PEIS by staphylococcal protein A (SPA). It was used to detect SjCAg in sera of rabbits which had been infected by Sj in order to acquire some optimum conditions for detecting SjCAg. Finally, the LP-PEIS with optimum conditions was used to detect SjCAg in sera of patients who had been infected by Sj, and was compared with sandwich ELISA.Results
A lot of optimum conditions of LP-PEIS for detecting SjCAg had been acquired. In the detection of patients' sera with acute Schistosomiasis, LP-PEIS has higher positive rate (100%) and lower false positive rate (3.0%) than sandwich ELISA (92.8%, 6.0%). However, there were no significant difference between LP-PEIS and sandwich ELISA.Conclusions
LP-PEIS can quantificationally detect SjCAg in patients' sera as well as sandwich ELISA. 相似文献96.
Shiping Liu Liang Zhang Qibin Li Ping Zhao Jun Duan Daojun Cheng Zhonghuai Xiang Qingyou Xia 《BMC genomics》2011,12(1):1-1
In line 12 of page 1, replace "GmGER 9" with "GmGER 15". 相似文献
97.
98.
Analysis of 16S rRNA amplicon sequencing options on the Roche/454 next-generation titanium sequencing platform 总被引:1,自引:0,他引:1
Tamaki H Wright CL Li X Lin Q Hwang C Wang S Thimmapuram J Kamagata Y Liu WT 《PloS one》2011,6(9):e25263
Background
16S rRNA gene pyrosequencing approach has revolutionized studies in microbial ecology. While primer selection and short read length can affect the resulting microbial community profile, little is known about the influence of pyrosequencing methods on the sequencing throughput and the outcome of microbial community analyses. The aim of this study is to compare differences in output, ease, and cost among three different amplicon pyrosequencing methods for the Roche/454 Titanium platformMethodology/Principal Findings
The following three pyrosequencing methods for 16S rRNA genes were selected in this study: Method-1 (standard method) is the recommended method for bi-directional sequencing using the LIB-A kit; Method-2 is a new option designed in this study for unidirectional sequencing with the LIB-A kit; and Method-3 uses the LIB-L kit for unidirectional sequencing. In our comparison among these three methods using 10 different environmental samples, Method-2 and Method-3 produced 1.5–1.6 times more useable reads than the standard method (Method-1), after quality-based trimming, and did not compromise the outcome of microbial community analyses. Specifically, Method-3 is the most cost-effective unidirectional amplicon sequencing method as it provided the most reads and required the least effort in consumables management.Conclusions
Our findings clearly demonstrated that alternative pyrosequencing methods for 16S rRNA genes could drastically affect sequencing output (e.g. number of reads before and after trimming) but have little effect on the outcomes of microbial community analysis. This finding is important for both researchers and sequencing facilities utilizing 16S rRNA gene pyrosequencing for microbial ecological studies. 相似文献99.
Hydrogen peroxide acts on sensitive mitochondrial proteins to induce death of a fungal pathogen revealed by proteomic analysis 总被引:1,自引:0,他引:1
How the host cells of plants and animals protect themselves against fungal invasion is a biologically interesting and economically important problem. Here we investigate the mechanistic process that leads to death of Penicillium expansum, a widespread phytopathogenic fungus, by identifying the cellular compounds affected by hydrogen peroxide (H(2)O(2)) that is frequently produced as a response of the host cells. We show that plasma membrane damage was not the main reason for H(2)O(2)-induced death of the fungal pathogen. Proteomic analysis of the changes of total cellular proteins in P. expansum showed that a large proportion of the differentially expressed proteins appeared to be of mitochondrial origin, implying that mitochondria may be involved in this process. We then performed mitochondrial sub-proteomic analysis to seek the H(2)O(2)-sensitive proteins in P. expansum. A set of mitochondrial proteins were identified, including respiratory chain complexes I and III, F(1)F(0) ATP synthase, and mitochondrial phosphate carrier protein. The functions of several proteins were further investigated to determine their effects on the H(2)O(2)-induced fungal death. Through fluorescent co-localization and the use of specific inhibitor, we provide evidence that complex III of the mitochondrial respiratory chain contributes to ROS generation in fungal mitochondria under H(2)O(2) stress. The undesirable accumulation of ROS caused oxidative damage of mitochondrial proteins and led to the collapse of mitochondrial membrane potential. Meanwhile, we demonstrate that ATP synthase is involved in the response of fungal pathogen to oxidative stress, because inhibition of ATP synthase by oligomycin decreases survival. Our data suggest that mitochondrial impairment due to functional alteration of oxidative stress-sensitive proteins is associated with fungal death caused by H(2)O(2). 相似文献