Effects of short chain fatty acids on radicle emergence and root growth in lettuce

Abstract. Short chain fatty acids inhibit both radicle emergence and root growth in lettuce. The transition from ineffectual to inhibitory levels occurs abruptly. Root growth is more sensitive to lower concentrations than radicle emergence and is invariant with chain length. The effect of short chain alcohols on radicle emergence is similar to that of short chain acids, but their comparatively severe inhibition of root growth varies with chain length. Alkanes of the same chain lengths have no noticeable effect. Respiration is not altered by a representative short chain fatty acid (heptanoic). Lettuce seeds are sensitized to phytochrome-absorbed light by short chain fatty acids as found by Berrie and co-workers.     

芜菁UF3GT基因的克隆及表达特性

目的:克隆‘津田’芜菁和‘赤丸’芜菁的UDP-葡萄糖∶类黄酮3-O-葡萄糖基转移酶(UF3GT)基因并研究其表达特性。方法:利用RT-PCR方法克隆‘津田’芜菁BrUF3GT1基因和‘赤丸’芜菁BrUF3GT2基因,并进行生物信息学分析;通过Northern杂交检测BrUF3GT1和BrUF3GT2基因的UV-A诱导表达特性;对BrUF3GT1和BrUF3GT2基因进行原核诱导表达。结果:BrUF3GT1和BrUF3GT2的开放读框为1407 bp,编码468个氨基酸残基;氨基酸序列分析显示,BrUF3GT1和BrUF3GT2与拟南芥UF3GT的同源性为87%,从第16~453位氨基酸残基的肽段具有糖基转移酶家族成员的结构域;BrUF3GT1和BrUF3GT2基因具有高度同源性,核苷酸序列在7个位点存在差异,推导的氨基酸序列在1个位点存在差异;Northern杂交结果显示,UV-A可以诱导BrUF3GT1和BrUF3GT2基因表达,基因的表达量与处理时间相关;原核诱导表达及纯化后可以获得相对分子质量分别约为51.88×103和51.89×103的BrUF3GT1和BrUF3GT2蛋白。结论:克隆了‘津田’芜菁和‘赤丸’芜菁的UF3GT基因,为初步阐明2种芜菁的花青素生物合成机理奠定了实验基础。     

稀有濒危植物在温州植物园的保护现状

经过三十多年的引种驯化工作,目前已有44种国家稀有濒危植物成功迁地保护在温州植物园,大部分生长良好。可结合实际情况,选择适应性强、具开发价值的部分植物进行推广。     

海洋生态系统调节服务价值评估方法及应用——以温州市为例

海洋生态系统服务可分为供给、调节、文化和支持4组服务,调节服务是海洋生态系统服务的关键构成要素之一。现行国家标准《海洋生态资本评估技术导则》(GB/T 28058-2011)中调节服务价值已有相应评估指标和方法,但与陆地生态系统的评估体系并不统一。为了更好地接轨陆地生态系统评估体系和将海洋生态系统服务价值评估纳入国民经济核算体系,首先对调节服务价值的评估指标和方法进行改进和完善,之后以温州海域为例开展应用验证,并与国标方法评估的结果进行比对。选择固碳、气候调节和废弃物处理3项指标,分别采用替代市场价格法和替代成本法对2013—2017年5年间温州海域生态系统提供的调节服务价值进行评估,并初步揭示其空间分布规律。结果表明,采用改进后的评估指标和方法,2013—2017年温州海域调节服务价值变化范围为(63.59—86.25)亿元;其中,以废弃物处理提供的服务价值占主导地位(56.53%—76.64%),其次是气候调节服务提供的价值(23.33%—43.45%),二者合计占调节服务价值的99.9%以上。可见,温州海域调节服务价值的贡献主要来自废弃物处理和气候调节服务提供的价值。温州海域面积8649 km~2,2013—2017年其调节服务价值平均分布密度范围为(73.52—99.72)万元/km~2。此外,温州海域提供的调节服务价值相当于同年温州市地区海洋生产总值的7.34%—11.88%,相当于同年温州市地区生产总值(GDP)的1.26%—2.00%,对温州市第二产业增加值的贡献度为17%—27%,由此表明温州海域调节服务价值对温州市经济发展有着重要的支撑作用。温州海域调节服务价值的空间分布总体呈现出从近岸向外海明显降低趋势。采用新的评估指标和评估方法,能大幅度提高调节服务的价值(是旧方法评估价值的6—9倍),从而使温州市海洋生态系统服务总价值得到大幅提升。本研究对温州市海洋生态系统调节服务价值的评估,反映出近年来温州市海洋生态环境处于良好状态,同时表明海洋生态系统为人类带来了巨大效益,也可为温州市海洋生态文明建设和海洋部门管理工作提供一定的决策依据。     

Novel Fraction Collector for Studying the Oviposition Rhythm in the Turnip Moth

Turnip moths, Agrotis segetum (Schiff.) (Lepidoptera: Noctuidae), were held in a transparent plastic box with a window opening to a rotating paper drum upon which the females could lay eggs. A novel fraction collector, consisting of a standard 24-hr wall timer and simple electronic circuit, served to rotate the paper in hourly increments. The entire apparatus was housed in an environmental chamber on a 16 hr light: 8 hr dark photoperiod at constant 23.7°C and 55% r.h. Under these conditions a circadian rhythm of egg laying was indicated with a mean activity time 0.2 hr before dark and standard deviation of 2.1 hr. The relative egg productions during the second to seventh day of oviposition peaked on the third day. Differences in the circadian rhythms of mating and oviposition are considered in terms of ecological fitness.     

苦豆子生物碱对萝卜蚜的毒力及其对几种酯酶的影响

苦豆子Sophoraalopecuroids（L．）的次生代谢物质为喹诺里西定生物碱类。本研究明确了该生物碱中的野靛碱对萝卜蚜（Lipaphiserysimi）有很高的毒杀作用,对其无翅成蚜的致死中浓度（LC50,浸渍法）为（4325±2．12）mg／L,优于著名的杀蚜生物碱毒黎碱和烟碱,两者对该试虫的LC50分别为（684．70±2．28）mg／L和（1090．65±2．01）mg／L。用小菜蛾（Plutellaxylostella）幼虫作试虫,得知苦豆子7种主要生物碱对昆虫的乙酰胆碱酯酶（AChE）有抑制作用,其抑制程度排序为：总碱＞野靛碱＞槐胺碱＞槐定碱＞槐果碱＞氧化苦参碱＞苦参碱＞苦豆碱。野靛碱和苦豆碱对α-乙酸萘酯酶、α-乙酸萘酯羧酸酯酶及酯酶同功酶的活性亦表现不同程度的抑制作用。     

Fermentation of brined turnip roots using Lactobacillus plantarum and Leuconostoc mesenteroides starter cultures

The controlled fermentation of turnip slices using Lactobacillus plantarum or Leuconostoc mesenteroides as starter cultures led to earlier acid production and earlier and more pronounced inhibition of Enterobacteriaceae than with uninoculated (natural) fermentation. Unlike the natural fermentation, the controlled fermentations did not show a yeast secondary fermentation and also had a better colour. Due to its ability to produce higher amounts of acid, the use of Lact. plantarum is more desirable than of Leuc. mesenteroides.     

Multi-domain Packing in the Aminoacylatable 3′ End of a Plant Viral RNA

Turnip yellow mosaic virus (TYMV) contains a tRNA-like structure (TLS) in its 3′ untranslated region (3′ UTR).  This highly structured element induces valylation of the viral RNA by host cell enzymes and is important for virus proliferation. Directly upstream of the TYMV TLS is an upstream pseudoknot domain (UPD) that has been considered to be structurally distinct from the TLS.  However, using a combination of functional, biochemical, and biophysical assays, we show that the entire 3′ UTR of the viral genome is a single structured element in the absence of cellular protein.  This packing architecture stabilizes the RNA structure and creates a better substrate for aminoacylation, and thus the UPD and TLS are functionally and structurally coupled.  It has been proposed that the TYMV TLS acts as a molecular switch between translation and replication. Our results suggest that this putative switch could be based on structural changes within the global architecture of the UTR induced by interactions with the ribosome. The TYMV TLS·UPD might demonstrate how RNA structural plasticity can play a role in regulation of biological processes.     

Acidic dileucine motifs in the cylindrical inclusion protein of turnip mosaic virus are crucial for endosomal targeting and viral replication

Previously we reported that the multifunctional cylindrical inclusion (CI) protein of turnip mosaic virus (TuMV) is targeted to endosomes through the interaction with the medium subunit of adaptor protein complex 2 (AP2β), which is essential for viral infection. Although several functionally important regions in the CI have been identified, little is known about the determinant(s) for endosomal trafficking. The CI protein contains seven conserved acidic dileucine motifs [(D/E)XXXL(L/I)] typical of endocytic sorting signals recognized by AP2β. Here, we selected five motifs for further study and identified that they all were located in the regions of CI interacting with AP2β. Coimmunoprecipitation assays revealed that alanine substitutions in the each of these acidic dileucine motifs decreased binding with AP2β. Moreover, these CI mutants also showed decreased accumulation of punctate bodies, which enter endocytic-tracking styryl-stained endosomes. The mutations were then introduced into a full-length infectious clone of TuMV, and each mutant had reduced viral replication and systemic infection. The data suggest that the acidic dileucine motifs in CI are indispensable for interacting with AP2β for efficient viral replication. This study provides new insights into the role of endocytic sorting motifs in the intracellular movement of viral proteins for replication.     

基于COⅠ基因对温州沿海岛屿疣荔枝螺遗传多样性研究

温州沿海岛屿众多,水文环境复杂,疣荔枝螺(Reishia clavigera)是岩相潮间带常见种,对其群体间遗传多样性的分析,有助于合理保护和开发利用种质资源。本实验对温州沿海14个典型岛屿的158个疣荔枝螺个体,进行细胞色素氧化酶亚基Ⅰ(COⅠ)基因片段序列测定,得到158条长度为672bp的序列,A、T、C、G四种碱基含量分别为23.0%、38.4%、17.4%和21.2%。共检测到保守位点562个,变异位点108个,其中包括简约信息位点57个,单突变位点51个。所有个体的核苷酸多样性指数Pi为0.008 0±0.029 7,单倍型多样性为指数Hd为0.978±0.006,平均核苷酸差异度为5.328。群体间遗传距离在0.005 7～0.011 1之间,群体内遗传距离在0.005 7～0.010 8之间,不同疣荔枝螺群体之间的遗传距离处于同一水平。霓屿岛和大竹峙岛群体内遗传距离最小,洞头岛群体内遗传距离最大。共检测到102个单倍型,大部分单倍型聚合为一支,没有形成明显的区系结构,各个岛屿的疣荔枝螺存在基因交流。