植物抗病作用机制与信号传导研究进展

随着植物抗病研究的发展，利用日益丰富的试验数据探索植物抗病作用机制和信号传导机制．有助于深入研究病原菌-寄主之间的相互作用关系，制定更为有效的植物病害防治措施。本文对目前植物抗性基因，病原菌无毒基因以及二者互作机制和抗病途径中的信号传导研究作一综述。     

植物化学物质生理调节作用关键信号通路研究进展

植物化学物质具有抗氧化、抗炎症、抗肿瘤和免疫增强等多种生理调节功能,这些生理调节功能有赖于细胞内存在的信号识别与传导通路,并最终经由相关关键转录因子及对应的效应基因的表达实现其调节功能。本文对植物化学物质在细胞内信号的识别与传导模式进行了归纳总结,并对参与其功能实现所经历的信号调节通路进行了综述。     

乳腺内氨基酸调控乳蛋白合成的分子作用机制

作为维持哺乳动物生命活动重要的"生物工厂",乳腺利用从流经血液中摄取的氨基酸等营养物质为底物合成乳蛋白。研究证实,氨基酸还可作为一种信号因子,通过乳腺内多种信号级联传导通路,调控乳蛋白基因的转录及翻译过程,从而影响乳腺中乳蛋白的合成。酪氨酸蛋白激酶-信号转导子和转录激活子(JAK-STAT)信号通路和哺乳动物雷帕霉素靶蛋白(m TOR)信号通路是乳蛋白基因转录和翻译过程中的主要调控路径。本文综述了乳腺JAKSTAT和m TOR信号通路的分子机制及氨基酸通过这些通路调控乳蛋白合成的研究进展,旨在进一步阐明氨基酸调控乳蛋白合成的作用机理。     

Harpin蛋白的研究进展

由植物革兰氏阴性病原菌编码产生的harpin蛋白是激发植物过敏反应的主要因子,具有显著的诱导植物抗性和促进生长发育等多种生物学效应,同时也是研究植物抗病信号传导的理想模型。基于对harpin蛋白的深入研究,国外已开发出新型、高效、安全的生物农药。本文综述了近年来harpin蛋白的研究进展。     

lncRNA在猪流产相关病毒感染中的作用研究进展

猪的繁殖力是决定其生产效率的重要因素,而病毒感染导致的猪流产问题严重影响猪的繁殖效率。了解猪流产相关病毒的致病机制有助于提高猪的繁殖效率,然而大量的研究主要集中在病毒与宿主的蛋白质或基因组DNA上,近年来,长链非编码RNA （long noncoding RNA,lncRNA）从新的视角揭示了病毒与宿主的相互作用,为研究二者之间的互作关系提供了新的途径。lncRNA是一组长度>200 nt的转录本,主要通过与DNA、RNA、染色质和蛋白质互作发挥功能,在某些发育阶段、组织和疾病状态中发生特异性表达,参与机体的多种调控。lncRNA是调控病毒与宿主相互作用的关键因子,在病毒感染宿主后lncRNA发生差异性表达,对应的靶基因富集到炎症和免疫相关的信号通路,参与机体的炎症、免疫和抗病毒反应。深入了解lncRNA在猪流产相关病毒与宿主之间的调控作用,对预防和治疗病毒感染导致的猪流产具有重要意义。作者对lncRNA及其与猪流产相关病毒的关系、宿主lncRNA与病毒的互作及调控通路展开了综述,并对其存在的问题及应用前景进行了展望,以期为猪的抗病育种、猪流产药物的开发和设计及流产类相关疾病的靶点治疗等提供理论依据。     

Harpin蛋白的研究进展

由植物革兰氏阴性病原菌编码产生的harpin蛋白是激发植物过敏反应的主要因子，具有显著的诱导植物抗性和促进生长发育等多种生物学效应，同时也是研究植物抗病信号传导的理想模型。基于对harpin蛋白的深入研究，国外已开发出新型、高效、安全的生物农药。本文综述了近年来harpin蛋白的研究进展。     

植物抗寒冻、抗旱、耐盐基因工程研究进展

综述了植物在各种环境胁迫下通过诱导相关胁迫基因的表达、进而激活相应的保护代谢途径,同时对抗逆信号传导和转录因子等的研究也作了概述,并综述了近年来国内外克隆、鉴定的抗逆基因的作用机制,及它们转入植物体内引起的植物抗性表达等。     

Bta-miR-223靶基因及调控网络的生物信息学分析

旨在预测奶牛microRNA-223(bta-miR-223)的候选靶基因,并对其进行蛋白质互作分析、信号通路富集分析,构建其可能参与的调控网络,为bta-miR-223参与乳腺炎抗性调控机制研究提供理论依据。利用Targetscan和miRWalk在线分析工具预测其候选靶基因,利用STRING和DAVID在线分析工具分别对候选靶基因进行蛋白质互作分析以及KEGG通路分析,最后使用Cytoscape可视化软件绘制bta-miR-223候选靶基因可能重点参与的调控网络。结果表明,bta-miR-223候选靶基因FBXO30与SMURF2,FBXW7与UBA2等存在蛋白互作关系。KEGG通路富集分析结果显示,这些候选靶基因参与上皮细胞的细菌入侵、胞吞作用以及PI3K-Akt、TGF-β、AMPK等信号通路。结果提示,bta-miR-223的候选靶基因FBXO30、SMURF2、FBXW7、UBA2等可能通过参与抗原加工、先天免疫系统和中性粒细胞脱颗粒反应,以及上皮细胞的细菌入侵、胞吞作用、PI3K-Akt等信号通路发挥重要作用。     

植物多糖通过核因子κB及丝裂原活化蛋白激酶/核因子E2相关因子2信号通路发挥抗氧化作用的机制

植物多糖是植物提取物中重要活性成分之一,具有抗氧化、免疫增强、抗肿瘤等多种生物学作用。在抗氧化作用方面,植物多糖通过核因子κB(NF-κB)信号通路减少炎症因子的分泌,缓解氧化应激损伤;通过丝裂原活化蛋白激酶/核因子E2相关因子2(MAPK/Nrf2)信号通路清除机体或细胞内自由基,提高抗氧化酶活性或含量,增强机体或细胞对氧化应激的抗性。本文主要综述了氧化应激产生的原因及其危害,并阐述NF-κB及MAPK/Nrf2信号通路在植物多糖发挥抗氧化作用中的研究现状以及存在问题,为植物多糖作为抗氧化剂的研究与应用提供理论参考。     

线粒体未折叠蛋白反应的研究进展

线粒体是细胞内重要的细胞器之一,调控多种细胞内信号通路,然而环境应激会导致线粒体堆积并产生大量错误折叠或未折叠蛋白,造成线粒体功能紊乱。目前研究发现多种由线粒体到细胞核的信号传导通路能够缓解线粒体应激反应,维持线粒体的正常功能状态。本综述就酿酒酵母中的逆行反应,哺乳动物细胞和线虫中的线粒体未折叠蛋白的分子机制及线粒体未折叠蛋白反应与线粒体自噬、天然免疫的相互关系进行重点介绍。     

Gastrointestinal nematode infection in sheep--a review of the alternatives to anthelmintics in parasite control

Efforts to curb production losses caused by nematode parasitism in sheep have led to the development of a number of control methods to complement or replace anthelmintics. The need for alternative control measures stems from the emergence of anthelmintic-resistant parasitic nematodes with reports of multi-class resistance to these drugs now emerging. A number of these control methods such as predacious microfungi, protein supplementation, plant extracts in feed and vaccines have demonstrated potential to control infection but require development and examination under natural conditions. Breeding for natural resistance to nematode infection has already shown success in controlling the disease under natural conditions. Selection for resistance is currently based on fecal egg count measurements but identification of genetic indicators of resistance will provide a more efficient method of selection. Current quantitative trait loci for nematode resistance include the MHC genes, interferon gamma gene, IgE gene and microsatellites on chromosome 1, 5 and 6. This paper reviews the current alternatives to anthelmintics to control infection, with an emphasis on breeding for host resistance and identification of genetic indicators of resistance.     

株型形成及牧草株型相关研究进展

牧草育种工作是草牧业可持续发展的重要基础,目前除了应用传统育种的方法外,应用分子育种方法也取得一些突破性进展,特别是在抗逆性分子育种研究上取得了一定的实际性成果。株型是综合的农艺性状,是影响植物群体结构及产量形成的重要性状。现在株型在一年生作物株型分子机理及调控网络等方面已进行了深入系统的研究,而对于牧草株型调控机理研究颇少,大多研究是在与产量相关性状及其基础性分子育种等方面。针对影响植物株型形成因素及其机理进行了归纳总结,并对牧草株型性状相关研究进展进行了综述,最后简要评述了当前在牧草株型育种研究上所存在的关键问题,提出了相关建议,并指出可借鉴作物株型育种前沿研究方向制定牧草株型育种的研究策略。     

甘肃岷县当归茎线虫病发生情况调查分析

2014年11月对甘肃省当归主产区岷县的5个乡镇42块当归田采用随机取样方法进行了系统调查,以了解当归茎线虫病的发生分布情况。调查结果表明,当归茎线虫病田间病株率达到25%~79%,病情指数达15.8~68.0,其中,以梅川镇梅川村发病最严重,发病率达79%,病情指数达68.0;在不同土壤深度、不同土壤类型、不同茬口作物根际土壤中均有腐烂茎线虫分布,但群体密度不同。以5.0~10cm土层分布比例较大,每100g达230头;以黑土中病原线虫密度较大,每100g达1 102头,与黄土和沙壤土相比线虫密度差异显著(P0.05);不同茬口作物中以黄芪茬口病原线虫密度较大,每100g达590头,与马铃薯、大豆、小麦茬口相比线虫密度差异均显著(P0.05)。     

Molecular mechanisms for anthelmintic resistance in strongyle nematode parasites of veterinary importance

Veterinarians rely on a relatively limited spectrum of anthelmintic agents to control nematode parasites in domestic animals. Unfortunately, anthelmintic resistance has been an emerging problem in veterinary medicine. In particular, resistance has emerged among the strongyles, a group of gastrointestinal nematodes that infect a variety of hosts that range from large herbivores to small companion animals. Over the last several decades, a great deal of research effort has been directed toward developing an understanding of the mechanisms conferring resistance against the three major groups of anthelmintics: macrocyclic lactones, benzimidazoles, and nicotinic agonists. Our understanding of anthelmintic resistance has been largely formed by determining the mechanism of action for each drug class and then evaluating drug‐resistant nematode isolates for mutations or differences in expression of target genes. More recently, drug efflux pumps have been recognized for their potential contribution to anthelmintic resistance. In this mini‐review, we summarize the evidence for mechanisms of resistance in strongyle nematodes.     

绿肥影响农田土传病害的研究进展

土传病害是制约我国农业可持续发展的因素之一。绿肥作为高效清洁的有机肥源,与主作物合理搭配,可有效降低主作物土传病害的发生和危害,是减少化学药剂使用的重要措施。因此,综述绿肥对土传病害的防控效果与机制,对于绿肥推广应用和土传病害绿色防控具有重要意义。绿肥影响作物土传病害的研究主要集中于土传真菌病害和线虫病害,且大多数研究表明,绿肥可通过增强主作物整体抗病水平,对病原菌的化感抑制作用和改善土壤理化性质,增加土壤微生物中拮抗菌多样性和丰富度等,显著降低主作物土传病害发病率和严重程度。然而,绿肥影响主作物病害的作用机制研究不够深入,绿肥-主作物搭配模式和绿肥调控主作物病害的社会经济学效益仍需探究。同时,加强绿肥-主作物病害一体化防控及绿肥与根际促生菌、生防菌等其他有机改良剂或与适当的化学防控措施之间协同作用的研究,是未来需要加强的研究方向。     

Assessment of genetic variability of resistance to gastrointestinal nematode parasites in Creole goats in the humid tropics

Goat production is widespread in the tropics. Goats are very susceptible to gastrointestinal nematode infection, but there is less evidence of their genetic resistance. Genetic resistance of Creole goats to gastrointestinal nematodes has been studied at Guadeloupe in the French West Indies since 1995. The objective of this research was to investigate genetic variation for resistance to gastrointestinal nematode infection, in order to introduce this trait into breeding schemes. Genetic variability was assessed within a Creole experimental flock. Forty-nine sire groups were characterized at weaning and 55 during fattening after weaning. Kids were naturally infected, mainly by Haemonchus contortus and Trichostrongylus colubriformis. Fecal egg counts were determined once at weaning and every 6 and 7 wk after drenching during fattening. Blood samples were collected every 7 wk during fattening for determination of packed cell volume. Live weights were recorded at weaning and at the beginning and middle of every infection period during fattening. Genetic parameters were estimated using the REML for multivariate animal models. The heritability estimate for transformed fecal egg count was 0.37+/-0.06 at weaning. During fattening, it increased from 0.14+/-0.05 at 4 mo to 0.33+/-0.06 at 10 mo. Heritabilities of packed cell volume ranged from 0.10 to 0.33. At weaning, maternal heritability of fecal egg count reached 0.26 and direct heritability 0.20. After 6 mo of age, maternal effects were found to be unimportant for fecal egg count and packed cell volume. Live weights presented significant genetic variability. Genetic relationships between fecal egg counts and live weight in infected pastures were never significant. Genetic correlations between packed cell volume and live weight decreased from 0.47 to 0.10 from weaning to 10 mo of age. These results demonstrated the feasibility of breeding for improved resistance to nematodes in Creole kids.     

内源脱落酸生理作用机制及其与苜蓿耐旱性关系研究进展

随着全球气候的恶化,水资源短缺等生态问题日益严重。在这样的背景下,作物的耐旱性研究成为人们研究的热点之一。脱落酸(ABA)作为胁迫激素,在植物干旱胁迫响应中发挥着重要而广泛的作用。植物细胞中,ABA通过2-甲基-D-赤藓糖-4-磷酸(2-C-methyl-D-erythritol-4-phosphate, MEP)途径合成,并最终与相应的受体结合并通过一系列的信号转导控制气孔关闭,或者通过其他通路调节胁迫相关的基因表达。紫花苜蓿是栽培广泛且品质优良的豆科牧草,干旱胁迫下苜蓿中脱落酸(ABA)会发生积累;同时,ABA水平的升高与苜蓿主根贮藏蛋白动态、基因表达以及一些渗透调节物质的积累密切相关。ABA与苜蓿耐旱性关系的研究正在逐渐深入,这些研究将深化人们对苜蓿耐旱机理的认识,并对苜蓿的育种具有深远影响。     

荒漠草原植物抗旱生理生态学研究进展

荒漠草原植物由于长期在干旱环境下生存,形成了一系列抵御干旱逆境的生理生态机制.研究其生理生态学适应机制,对当前植物抗逆育种、生态环境恢复和作物抗旱性能评价等都具有重要意义.简要回顾了近20年来国内外在荒漠草原植物生理生态学方面的研究进展,包括形态结构、水势和渗透调节、光合和水分利用效率、蒸腾和气孔导度以及种群和群落等对水分胁迫的响应,并结合各个领域当前采用的主要实验手段进行了评述.进而分析了我国在上述领域的研究现状和应予以重点关注的问题.     

Slowing the spread of anthelmintic resistant nematodes of sheep and goats in the United Kingdom.

Anthelmintic resistant nematodes pose an increasing threat to animal welfare and lamb production on lowland sheep farms in the United Kingdom. Based on published information on anthelmintic resistance in nematodes and insecticide resistance in arthropods, seven recommendations are made for reducing the development and spread of anthelmintic resistant nematodes. The two most important are probably to prevent the introduction of resistant worms through the purchase of stock and to reduce the reliance on frequent anthelmintic treatments by using epidemiological principles of nematode control.