花生硬脂酰-ACP酸脱饱和基因FAB2表达的分子机制

FAB2位于油酸合成通路的上游,编码硬脂酰-ACP脱饱和酶,调控硬脂酸(C18:0)向油酸(C18:1)转化。本研究发现高油酸品种开农176种子发育前期FAB2的表达量升高,而成熟期油酸过量积累会抑制FAB2的表达。利用开农176与开农70构建F2杂交群体,发现当植株油酸含量超过60%时会从整体水平上抑制FAB2的表达。种子发育前期,油酸不断积累会导致过氧化物酶活性升高,并且活性氧含量随之增加;但是在种子发育后期均降低,该结果与FAB2的表达量变化趋势相同。亚细胞定位结果表明, FAB2与FAD2分别定位于叶绿体与内质网。FAB2编码区序列多态性分析显示,该蛋白序列氮端的氨基酸结构缺失可能会导致硬脂酸含量升高。FAB2启动子序列存在大量AT碱基的富集区域,并且含有光响应、激素调控、转录因子结合的保守顺式元件。本研究发现过量积累的油酸会激活过氧化物酶介导的活性氧信号途径,进而通过细胞核内的未知转录因子调节上游基因FAB2的表达量,该结果不仅拓展了对FAB2的功能认知,也为培育高油酸花生品种提供了相关的理论指导。     

Effect of Psammaplin A on in vitro Development of Bovine Aging Oocytes

To investigate the effect of histone deacetylation inhibitor Psammaplin A (PsA) on the development of bovine aging oocytes in vitro,oocytes were randomly divided into control group,aging group and 50 mmol/L PsA treated aging group (PsA group).Immunofluorescence staining and JC-1 were used to detect the blastocyst rate of bovine oocytes after parthenogenetic activation,the number of cells in blastocysts,apoptosis,reactive oxygen species (ROS),glutathione (GSH) and mitochondrial membrane potential intensity of embryos.The results showed that the blastocyst rate of the aging group was significantly lower than that of PsA and control groups (P<0.05).The blastocyst rate of PsA group was not significantly different from that of control group (P>0.05).The number of cells in the blastocysts of control group and PsA group were significantly higher than that of aging group (P<0.05).The number of cells in the blastocysts of PsA group was not significantly different from that of control group (P>0.05).The apoptosis rate in aging group was significantly higher than that of control and PsA groups (P<0.05),the apoptosis rate of PsA group was significantly higher than that of control group (P<0.05).The GSH level of MⅡ oocytes in aging group was significantly lower than that of control and PsA groups (P<0.05).There was no significant difference in GSH level between control and PsA groups (P>0.05).The ROS level of the embryos in aging group was significantly higher than that of control and PsA groups (P<0.05).The ROS level in PsA group was significantly higher than that of control group (P<0.05).The mitochondrial membrane potential of early embryos of aging group 4-8 cells was significantly lower than that of control and PsA groups (P<0.05).The mitochondrial membrane potential intensity of control group was significantly higher than that of PsA group (P<0.05).In summary,PsA could effectively delay the aging of bovine oocytes and improve the quality of oocytes.     

Overexpression of StRbohA in Arabidopsis thaliana enhances defence responses against Verticillium dahliae

Plant NADPH oxidases are key regulators of plant–microbe interactions and reactive oxygen species (ROS) are essential to plant defences against pathogens. A significant part in the role played by ROS has been ascribed to plant respiratory burst oxidase homologs (RBOHs). In potato (Solanum tuberosum), where RBOHs were previously shown to be involved in wound-induced oxidative burst, we assessed their expression after inoculation with Verticillium dahliae Kleb. and showed that StRbohA was the only homolog to be differentially induced in potato in response to inoculation. In order to investigate the potential role of this gene in plant protection against wilt diseases, we used Agrobacterium-mediated transformation of Arabidopsis to assess the effects of its overexpression on plant responses to V. dahliae. After inoculation with this pathogen, the transformed Arabidopsis line overexpressing StRbohA showed lower disease severity (percent damaged leaf area and vascular discoloration) as compared to the wild type. It also had higher ROS production and more cell death caused by hydrogen peroxide (H₂O₂), compared to the wild type. Suberization of root cells was also more pronounced in the line overexpressing StRbohA, and supports a possible role for StRBOHA in plant resistance to V. dahliae. Together, these findings indicate that overexpressed StRbohA in Arabidopsis enhances the ROS-mediated defence mechanisms against V. dahliae and can be a potential tool to improve plant resistance to this and other soilborne pathogens that cause wilts in economically important crops.     

Effect of AIR on Inflammatory Reaction Infected by Brucella

In order to investigate the effect of AIR on inflammatory reaction infected by Brucellamelitensis (16M), the AIR domain of Tecpr1 gene of murine macrophages RAW264.7 were knocked down (I-A), overexpressed (O-A) and reversed (OA-IA). Using the chlorine fluorescein (DCFH-DA) as a probe, we detected the variation of ROS production and mitochondria distribution by confocal laser scanning microscopy. We observed the expression changes of NLRP3, ASC and Caspase-1 by qRT-PCR and the expression changes of IL-18,IL-1β and Caspase-1 in host cells by ELISA. The results showed that 16M could stimulate RAW264.7 cells to produce ROS by time-dependent pathway, and I-A group and O-A group showed more abnormal accumulation of mitochondrial. The results of qRT-PCR and ELISA suggested that it had effect on the expression levels of NLRP3, ASC,Caspase-1 and IL-18, IL-1β and Caspase-1 in cells of different groups. Those results indicated that with AIR gene deletion, the release amount of ROS changed, mitochondrial clustered abnormally, and AIR was closely related to the activation of inflammasomes and induction of inflammatory reactions.     

Changes in peroxidase activity and lignin content of cultured tea cells in response to excess manganese

Abstract

The present study was undertaken to identify the effects of manganese (Mn) on the activity of peroxidase (PO) and the amount of ascorbic acid (AsA) and lignin, as well as the cell viability of suspension-cultured tea cells (Camellia sinensis L. cv. Yabukita). Cells were grown in B5 medium (containing 0.06 mmol L^?1 Mn) and cultured for 24 h in medium with a Mn concentration of 0.9 mmol L^?1 as an excess treatment. No significant difference was observed between cellular growth and the viability of the cultured tea cells after treatment with excess Mn compared with cells grown under control conditions, although the content of Mn in cells in the excess Mn treatment was 12-fold higher than that of the control cells. The amount of total AsA was also not affected by the Mn treatment. The activity of ionically wall-bound peroxidase (IPO) increased in the presence of excess Mn, unlike the content of lignin. Conversely, the activities of soluble PO and covalently wall-bound PO decreased with excess Mn. These findings suggested that IPO might contribute to Mn tolerance in tea cells. However, its role in the mechanism(s) of Mn tolerance has not been elucidated.     

机器人在设施农业领域应用现状及发展趋势分析

机器人技术在设施农业领域的广泛应用,不仅大幅提升农业产量,也能够体现一个国家农业现代化科技水平。机器人操作系统ROS的兴起,逐渐成为国内外设施农业机器人研究开发的热点。对国内外机器人设施农业领域相关研究探讨分析,综述当前机器人在种苗嫁接移栽、喷药施肥、果蔬收获加工、畜禽健康养殖等设施农业领域方面的应用现状,总结归纳SLAM地图构建、自主导航、机器视觉三种机器人关键技术研究趋势,并对比分析路径规划中Dijkstra算法、BFS算法、A*算法的优缺点以及机器视觉在果蔬采摘分选等领域的发展趋势。面对农业向智慧农业方向发展,总结并展望设施农业机器人未来发展趋势。     

稀释液中添加海藻糖对猪冷冻精液质量参数和活性氧的影响

本试验旨在探讨海藻糖对猪精子冷冻效果以及精子内活性氧(ROS)的含量影响。试验分对照组和4个海藻糖处理组(0.025,0.05,0.1和0.2 mol/L)。精子冷却后,添加0.1 mol/L海藻糖处理组精子活力显著(P<0.05)高于对照组,而精子内和稀释液中各组间ROS发生量都没有显著的差异。精子冷冻解冻后,添加0.05 mol/L海藻糖处理组的精子活力显著(P<0.05)高于对照组;添加0.05 mol/L和0.1 mol/L海藻糖处理组的精子生存率显著(P<0.05)高于对照组;添加0.1 mol/L海藻糖处理组顶体完整的精子百分比显著(P<0.05)高于对照组;4个海藻糖处理组膨胀精子百分比都显著(P<0.05)高于对照组;添加0.025 mol/L海藻糖处理组ROS水平显著(P<0.05)低于对照组。结果表明:海藻糖对精子冷冻保存是有益的,且能抑制精子内ROS的发生,但它的作用机制有待于进一步的研究。     

Brucella intracellular life: from invasion to intracellular replication

Brucella organisms are pathogens that ultimate goal is to propagate in their preferred niche, the cell. Upon cell contact the bacteria is internalized via receptor molecules by activating small GTPases of the Rho subfamily and by a moderate recruitment of actin filaments. Once inside cells, Brucella localizes in early phagosomes, where it avoids fusion with late endosomes and lysosomes. These early events require the control of Rab small GTPases, and cytokines such as the G-CSF. Then, the bacterium redirects its trafficking to autophagosomes and finally reaches the endoplasmic reticulum, where it extensively replicates. Some of the bacterial molecular determinants involved in the internalization and early events after ingestion are controlled by the BvrS/BvrR two component regulatory system, whereas the intracellular trafficking beyond this early compartments are controlled by the VirB type IV secretion system. Once inside the endoplasmic reticulum, Brucella extensively replicates without restricting basic cellular functions or inducing obvious damage to cells. The integrity of Brucella LPS on the bacterial surface is one of the required factors for Brucella intracellular survival, and therefore for virulence.     

活性氧(ROS)对小鼠早期胚胎胚细胞分裂的影响

在体外CZB培养的不同时期添加过氧化氢(2.1μmol/L),发育至囊胚阶段,制作胚胎标本,观察其囊胚发育率、胚细胞数和分裂相数。结果显示:0~12 h组和0~72 h组的胚胎发育率显著低于其他几组(P<0.05),对照组、12~24 h组、24~36 h组、36~48 h组之间均差异不显著(P>0.05);各组之间的胚细胞数和分裂指数均无显著差异。说明胚胎在体外培养时,2细胞期胚胎对外源性H2O2最敏感,也最容易发生发育阻滞。但是经H2O2处理之后,度过2细胞期发育阻滞的胚胎能在以后的发育中发生补偿性生长,其胚细胞数和分裂指数都和体外正常发育的胚胎没有差异。     

日粮镁对肉仔鸡腿肌中活性氧产量的影响

本试验目的是研究日粮镁水平对肉仔鸡腿肌中活性氧(reactive oxygen species , ROS)产量的影响。96只AA肉仔鸡随机分配到低镁日粮组和对照组,每组6个重复,每个重复8只鸡,分别喂以镁含量1 .2 g/kg或2 .4 g/kg的日粮。与对照组相比,低镁组肉仔鸡腿肌中谷胱甘肽(glutathione , GSH)的含量降低了27 %(P<0 .01) ,丙二醛(malondialdehyde, MDA)的含量提高了40 %(P<0 .01)。采食低镁日粮的肉仔鸡腿肌匀浆液的ROS信号峰的高度显著高于对照组(P<0 .01)。对照组腿肌镁的浓度(30 .27 mg/kg)显著高于低镁组腿肌镁的浓度(27 .40 mg/kg)。腿肌中铁、钙的含量在两组之间差异不显著(P>0 .05)。与对照组相比,低镁组腿肌线粒体复合酶Ⅰ、Ⅱ、Ⅲ、Ⅳ的活性分别提高了28 %、23 %(P<0 .01)、35 %(P<0 .01)和30 %,线粒体复合酶Ⅰ、Ⅱ、Ⅲ、Ⅳ的活性与ROS产量之间呈显著的负相关关系(P<0 .05)。除C18∶2的含量显著高于对照组外,其他多不饱和脂肪酸含量在两组之间没有差异。本试验结果表明低镁日粮实质性地提高肉仔鸡腿肌中ROS的产量,低镁日粮降低腿肌中镁的浓度,诱导了线粒体呼吸链酶活性升高,从而提高了ROS的产量。