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91.
Na+/H+逆向转运蛋白(Na+/H+antiporter,NHX)基因家族在植物响应盐胁迫中发挥重要作用。本研究鉴定了大白菜NHX基因家族成员,并分析了大白菜NHX基因(Brassica rapa ssp.Pekinensis NHX,BrNHXs)响应高温、低温、干旱和盐胁迫等非生物逆境的表达模式。结果表明,在大白菜中共鉴定到9个NHX基因家族成员,分布在大白菜的6条染色体上,其氨基酸数目在513–1154 aa之间,相对分子量集中在56804.22–127856.66 kDa,等电点位于5.35–7.68之间。该基因家族成员主要存在于液泡中,基因结构完整,外显子的数目介于11–22之间。大白菜NHX基因家族编码的蛋白质二级结构都具有α-螺旋、β-转角和不规则卷曲结构,其中α-螺旋发生频率较高。实时荧光定量PCR(quantitative real-time PCR,qRT-PCR)分析显示,该基因家族成员在高温、低温、干旱和盐胁迫下均有不同程度地响应,且在不同时间表达差异显著。以BrNHX02和BrNHX09对这4种胁迫的响应最为显著,表达量在处理72 h时均显著上调,可作为候选基因进一步验证其功能。 相似文献
92.
Jong An Lee Jung Ho Ahn Gi Bae Kim Sol Choi Ji Yeon Kim Sang Yup Lee 《Biotechnology and bioengineering》2023,120(1):203-215
Microbial production of various TCA intermediates and related chemicals through the reductive TCA cycle has been of great interest. However, rumen bacteria that naturally possess strong reductive TCA cycle have been rarely studied to produce these chemicals, except for succinic acid, due to their dependence on fumarate reduction to transport electrons for ATP synthesis. In this study, malic acid (MA), a dicarboxylic acid of industrial importance, was selected as a target chemical for mass production using Mannheimia succiniciproducens, a rumen bacterium possessing a strong reductive branch of the TCA cycle. The metabolic pathway was reconstructed by eliminating fumarase to prevent MA conversion to fumarate. The respiration system of M. succiniciproducens was reconstructed by introducing the Actinobacillus succinogenes dimethylsulfoxide (DMSO) reductase to improve cell growth using DMSO as an electron acceptor. Also, the cell membrane was engineered by employing Pseudomonas aeruginosa cis-trans isomerase to enhance MA tolerance. High inoculum fed-batch fermentation of the final engineered strain produced 61 g/L of MA with an overall productivity of 2.27 g/L/h, which is the highest MA productivity reported to date. The systems metabolic engineering strategies reported in this study will be useful for developing anaerobic bioprocesses for the production of various industrially important chemicals. 相似文献
93.
Sua Jeong Ji Seon Shim Seok Kyo Sin Kang-Sik Park Jung-Ha Lee 《Journal of cellular physiology》2023,238(1):210-226
Cav3.1 T-type Ca2+ channels play pivotal roles in neuronal low-threshold spikes, visceral pain, and pacemaker activity. Phosphorylation has been reported to potently regulate the activity and gating properties of Cav3.1 channels. However, systematic identification of phosphorylation sites (phosphosites) in Cav3.1 channel has been poorly investigated. In this work, we analyzed rat Cav3.1 protein expressed in HEK-293 cells by mass spectrometry, identified 30 phosphosites located at the cytoplasmic regions, and illustrated them as a Cav3.1 phosphorylation map which includes the reported mouse Cav3.1 phosphosites. Site-directed mutagenesis of the phosphosites to Ala residues and functional analysis of the phospho-silent Cav3.1 mutants expressed in Xenopus oocytes showed that the phospho-silent mutation of the N-terminal Ser18 reduced its current amplitude with accelerated current kinetics and negatively shifted channel availability. Remarkably, the phospho-silent mutations of the C-terminal Ser residues (Ser1924, Ser2001, Ser2163, Ser2166, or Ser2189) greatly reduced their current amplitude without altering the voltage-dependent gating properties. In contrast, the phosphomimetic Asp mutations of Cav3.1 on the N- and C-terminal Ser residues reversed the effects of the phospho-silent mutations. Collectively, these findings demonstrate that the multiple phosphosites of Cav3.1 at the N- and C-terminal regions play crucial roles in the regulation of the channel activity and voltage-dependent gating properties. 相似文献
94.
95.
生物脱氮是由微生物主导的地球氮循环中的重要环节之一,主要包括硝化、反硝化和厌氧氨氧化(anaerobic ammonium oxidation,anammox)等过程。在微生物联合作用下,污水中的有机氮及氨氮经一系列作用转化为氮气,这种经济高效、环境友好的处理工艺在世界范围内得到广泛应用。群体感应(quorum sensing,QS)以信号分子为媒介通过改变菌群密度和周围环境变化来调节微生物的各种行为。大量的研究已证实调控QS信号分子在生物脱氮中具有应用潜力。本文介绍了各种信号分子类型,从基因组学、实际应用等方面综述了各类信号分子以及检测方法,同时针对酰基高丝氨酸内酯(acyl homoserine lactones,AHLs)类信号分子在生物脱氮中的作用进行详细介绍。然而不足之处在于信号分子研究只是停留在实验室阶段,仅仅研究了单一信号分子对生物脱氮的影响。未来可将信号分子应用于实际污水,研究多种信号分子共同作用以及多种微生物之间的QS现象。 相似文献
96.
儿童最大有氧活动能力的发展特征 总被引:4,自引:1,他引:3
本文报告了我国463名10-19岁儿童青少年的最大有氧活动能力的发展特征。在青春早期,男女童的最大吸氧量绝对值均随年龄增长而增加,男童由1.75升/分增至3.10升/分,女童由1.44升/分增至2.07升/分,女童增长较少;以后女童即稳定于这一水平,男童仍略有增长。按身高及按最大心率计标的相对值与其有相似的特征。按体重和瘦体重计算的相对值,在男女童都未见随年龄增长的规律。男童VO2max绝对值及各 相似文献
97.
98.
1 引言 柳牡蛎蚧(Lepidosaphes salicina Bersch)(同翅目:盾蚧科)是一种以为害杨树为主的刺吸式害虫之一,广泛分布于“三北”防护林区,该蚧一年发生一代,以卵越冬。通过刺吸式口器刺入树皮内,吸取树木养分和水分,并使树木表皮栓化。同时,由于枝干被蚧壳所覆盖,对呼吸及光合作用也有影响,特别是幼树被害后,一般 相似文献
99.
Jia Chen Min Zhao Hongjuan Zhou Yiyuan Tang Wei Ji Jianhua Shao Chunjie Zhao Chunchao Zhao 《化学与生物多样性》2023,20(4):e202300246
Viburnum luzonicum is widely distributed in China. Its branch extracts showed potential α-amylase and α-glucosidase inhibitory activities. In order to discover new bioactive constituents, five undescribed phenolic glycosides, viburozosides A−E ( 1 – 5 ), were obtained by bioassay-guided isolation coupled with HPLC-QTOF-MS/MS analysis. Their structures were elucidated by spectroscopic analyses, including 1D NMR, 2D NMR, ECD, and ORD. All compounds were tested for their α-amylase and α-glucosidase inhibitory potency. Compound 1 showed significantly competitive inhibition against α-amylase (IC50=17.5 μM) and α-glucosidase (IC50=13.6 μM). 相似文献
100.
Xuebing Xu Tong Wu Renjie Lin Shengze Zhu Jie Ji Dandan Jin Mengxiang Huang Wenjie Zheng Wenkai Ni Feng Jiang Shihai Xuan Mingbing Xiao 《Journal of cellular and molecular medicine》2023,27(23):3672-3680
The migrasome is a new organelle discovered by Professor Yu Li in 2015. When cells migrate, the membranous organelles that appear at the end of the retraction fibres are migrasomes. With the migration of cells, the retraction fibres which connect migrasomes and cells finally break. The migrasomes detach from the cell and are released into the extracellular space or directly absorbed by the recipient cell. The cytoplasmic contents are first transported to the migrasome and then released from the cell through the migrasome. This release mechanism, which depends on cell migration, is named ‘migracytosis’. The main components of the migrasome are extracellular vesicles after they leave the cell, which are easy to remind people of the current hot topic of exosomes. Exosomes are extracellular vesicles wrapped by the lipid bimolecular layer. With extensive research, exosomes have solved many disease problems. This review summarizes the differences between migrasomes and exosomes in size, composition, property and function, extraction method and regulation mechanism for generation and release. At the same time, it also prospects for the current hotspot of migrasomes, hoping to provide literature support for further research on the generation and release mechanism of migrasomes and their clinical application in the future. 相似文献