Diverse Regulations of Viral and Host Genes in Tomato Germplasms Responding to Tomato Yellow Leaf Curl Virus Inoculation

Tomato yellow leaf curl virus(TYLCV)is the dominating pathogen of tomato yellow leaf curl disease that caused severe loss to tomato production in China.In this study,we found that a TYLCV-resistant tomato line drastically reduced the accumulation of viral complementary-sense strand mRNAs but just moderately inhibited that of viral DNA and virion-sense strand mRNAs.However,two other resistant lines did not have such virus inhibition pattern.Analysis of differential expressed genes showed that the potential host defense-relevant processes varied in different resistant tomatoes,as compared to the susceptible line,suggesting a diversity of tomato TYLCV-resistance mechanisms.

Tomato leaf curl Bangladesh病毒完整基因组上微卫星分布

为了展示Tomato leaf curl Bangladesh病毒完整基因组上的微卫星分布特性。借助MATLAB软件、应用最优完全子图算法,提取并展示NCBI数据库中Tomato leaf curl Bangladesh病毒完整基因组(AF_188481.1)上的微卫星分布特性,计算1-碱基组至6-碱基组在完整基因组序列上重复出现的次数和位置,展示它们的分布规律(指数函数)。结果表明:Tomato leaf curl Bangladesh病毒完整基因组(AF_188481.1)上各种N-碱基组(N取1至6)最大的重复出现次数,随N按指数函数数减少;笔者提取和展示Tomato leaf curl Bangladesh病毒完整基因组序列微卫星分布特性(特别是微卫星各种N-碱基组重复出现的位置和次数)的方法,可以系统地运用到其他病毒完整基因组序列微卫星分布特性的提取和展示中,从而为有效利用微卫星分布特性研究完整基因组的结构和功能、遗传和变异规律提供完备、仔细的数据支撑。

基于CURL异构数字资源统一检索的研究

运用CURL技术,实现对不同异构数字资源的统一检索。首先通过嗅觉器抓取和分析不同异构数字资源的传递参数,对传递参数进行元数据描述以后,运用CURL把参数传递到不同的异构数字资源库,最后通过分析传回的网页,实现在同一页面显示不同异构数字资源的检索结果。通过对北京农业数字图书馆不同异构数字资源的整合,实现了对馆内异构数字资源的统一检索。

基于CURL的大学异构数字资源统一查询系统研究

文章通过分析异构数字资源统一查询的流程模型和实现方式,提出针对大学图书馆数字资源的异构性,对不同数据源采用不同的统一查询方式。基于对需要查询的数据源统一资源定位符(URL)和查询参数定义的分析,以天津商业大学图书馆CNKI期刊全文数据库为例,重点分析采用CURL访问组件代理查询图书馆采购的专业数据库。

豌豆卷曲突变基因curl的染色体定位

利用一套 5个豌豆染色体易位系和 2个形态标记基因系chl 7及Viola为标记材料 ,对豌豆卷曲突变基因curl进行了染色体定位。结果表明 ,突变基因curl位于豌豆第 3染色体的长臂上 ,处于黄化基因chl 7和种皮皱纹基因r之间 ,排列顺序为r curl (chl 7) ,curl与chl 7之间的交换值为 34.2 4%±4.5 7%,与r之间的交换值为 19.79%± 3 .5 5 %。

基于CURL的网络学习资源聚合系统开发

设计并实现了一个基于CURL的网络学习资源聚合系统.利用CURL多线程函数将数据使用GET或POST方式同时发送给所有资源网站,对资源网站返回的HTML代码进行统一编码,使用正则表达式提取返回代码的搜索结果区域,使用PHP DOM操作类修正代码中的图像和链接的URL地址,再将所有返回代码载入到同一个页面中,并使用瀑布流模型实现逐段加载.

H(curl)-椭圆问题不连续Galerkin法的后验误差估计

针对Lipschitz多面体区域上H(curl)-椭圆问题的不连续Galerkin法,提出了一种新的基于残量型的后验误差估计,并证明了该后验误差的一个上界估计.其中问题的最困难性在于如何处理跳跃项中出现的局部网格尺寸的负次幂.

含时div－curl引理的一个证明

本文中我们用Ｆｏｕｒｉｅｒ分析方法证明了含时的ｄｉｖ－ｃｕｒｌ引理。

Response of the cold water mass in the western South China Sea to the wind stress curl associated with the summer monsoon

Analysis of climatological observation temperature data reveals that during the southwesterly monsoon, there exists a low tempera- ture zone east of Vietnam. It cools down from June to August and warms up in September. Meanwhile, during this period, the cold water mass spreads eastward to the deep basin. Numerical experiments validate the results of data analysis and further verify that there are two basic factors that induce the Vietnam cold water. The major one is the strong local positive wind stress curl, which leads to the divergence of sea surface water and the upward supplement of lower layer water in the deep basin. Another minor one is the alongshore component of southwesterly monsoon, which drives the offshore Ekman transport and coastal upwelling in the shallow region along the Vietnam coast. In addition, the negative wind stress curl in the southern South China Sea inputs negative vorticity to the ocean and drives a strong anticyclonic gyre, which affects the spatial distribution of the cold water evidently.

Molecular and biological characterization of melon-infecting squash leaf curl China virus in China

It has been reported that squash leaf curl China virus(SLCCNV)infects some Cucurbitaceae crops except for melon(Cucumis melo L.).A new disease of melon exhibiting severe leaf curl and dwarfing was observed in Hainan Province of China.In this study,the pathogen was identified as SLCCNV through biological and molecular characterization.The isolate(SLCCNV-HN)possess a bipartite genome,DNA-A(HM566112.1)with the highest nucleotide identity(99%)to SLCCNV-Hn(MF062251.1)pumpkin and SLCCNV-Hn61(AM260205.1)squash isolates from China,whereas DNA-B(HM566113.1)with the highest nucleotide identity(99%)to SLCCNV-Hn(MF062252.1).Phylogenetic analyses based on the full-length SLCCNV-HN DNA-A and-B sequences indicated that SLCCNV-HN melon isolate is clustered with SLCCNV-Hn pumpkin,SLCCNV-Hn61 and SLCCNV-SY squash isolates from southern China,forming an independent cluster.Infectious clone of SLCCNV-HN was constructed and the melon plants were inoculated and the infection rate is 100%,the systemic symptoms in melon showed identical to those of melon plants infected in fields.Additionally,melon plants transmission of this virus by Bemisia tabaci with a transmission rate of 95%(19/20)showed leaf curl and dwarf symptoms 15 days post transmission,thereby fulfilling Koch’s postulates.Analysis of genomic organization and phylogenetic trees indicated that SLCCNV-HN melon isolate belongs to the Begomovirus genus.To the best of our knowledge,this is the first characterization of meloninfecting SLCCNV through its genome,infectious clone and transmission.

Monoclonal Antibodies Against the Whitefly-Transmitted Tomato Yellow Leaf Curl Virus and Their Application in Virus Detection

Tomato yellow leaf curl virus（TYLCV）is a species of the family Geminiviridae,causing serious yield losses in tomato production.The coat protein（CP）gene of TYLCV isolate SH2 was expressed in Escherichia coli BL21（DE3）using pET-32a as the expression vector.The recombinant protein was purified through Ni＋-NTA affinity column and used to immunize BALB/c mice.Three hybridoma cell lines（2B2,2E3 and 3E10）secreting monoclonal antibodies（MAbs）against TYLCV CP were obtained by fusing mouse myeloma cells（Sp 2/0）with spleen cells from the immunized BALB/c mouse.The titers of ascitic fluids of three MAbs ranged from 10-6 to 10-7 in indirect-ELISA.Isotypes and subclasses of all the MAbs belonged to IgG1,κ light chain.Triple antibody sandwich enzyme-linked immunosorbent assay（TAS-ELISA）showed that the MAb 3E10 could react with five begomoviruses infecting tomato,while the other two（2B2 and 2E3）mainly reacted with TYLCV.TAS-ELISA was set up using the MAb 3E10,and the established method could successfully detect virus in plant sap at 1：2 560（w/v,g mL-1）.Detection of field samples showed that begomoviruses were common in tomato crops in Zhejiang Province,China.

基于cURL的在线环境报警系统的设计

根据新兴铸管股份有限公司现有监测系统数据流向,利用cURL、LAMP等工具开发出一种在线环境报警系统。系统运行期间抓取数据3 417 536条,触发警报104次,实现了无人值守、数据异常报警等功能,保证了环境效益、社会效益的双向收益。

Isolation and Identification of Squash Leaf Curl China Virus in Zucchini

[Objectives]In 2019,virus diseases occurred widely on zucchini planted in Shandong Province.The disease symptom was different from previous reports.This study aimed to identify the pathogen causing the zucchini virus disease.[Methods]Ten diseased zucchini leaves were collected in the field and used as materials for PCR and sequencing.[Results]PCR detection and sequencing showed that the nucleotide sequence of the amplified fragment had the highest identity with the squash isolate of squash leaf curl China virus(SLCCNV)(MW389919.1)in Guangdong Province.Primers were further designed for amplifying the full-length SLCCNV.The full-length DNA-A was 2730 bp(OM692270.1),and the full-length DNA-B was 2711 bp(OM692269.1).Through sequence alignment,it was found that the DNA-A sequence shared identity of 89.65%-99.42%with registered SLCCNV,and the identity with the SLCCNV-GDHY pumpkin isolate(MW389919.1)in Guangdong was the highest,at 99.42%.The DNA-B sequence was identical with registered SLCCNV in the range of 81.82%-97.29%,and the identity with the SLCCNV-GDHY pumpkin isolate(MW389918.1)in Guangdong,was the highest,at 97.29%.Therefore,it was speculated that SLCCNV is the pathogen of zucchini virus disease.Since the virus was first found on zucchini in Shandong,it was named SLCCNV-SD.[Conclusions]This study provides materials for the research on the spread of SLCCNV in China and the analysis of population genetic characteristics,as well as a reference for the prevention and control of the virus in zucchini.

Experimental studies on curling development of artificial soils

Soil curling is an important phenomenon associated with volume changes induced by increasing soil suction upon desiccation.The study of soil behaviors associated with drying in soils(e.g.soil shrinkage,desiccation cracks and curling)has received increasing attention over the last few years,which has been mainly driven by the forecast climate change that will warm up our planet.There are significant gaps in the current knowledge related to the factors that control the development of curling deformations in soils.For this,the curling phenomenon is investigated through laboratory desiccation tests on different mixtures of artificial soils.The effects of soil grain size distribution,mineralogy,soil microstructure,and soil water content on the curling deformation are analyzed.Digital photos were taken at regular time intervals during the tests to understand the volume changes in the soil samples during drying.It is found that soil fabric and soil water content have significant effects on curling scenario.It is observed that the percentage of sand particles and the initial water content play a critical role in the development of soil curling.Samples of pure clayey minerals experienced shrinkage without or with minor curling during drying.

Free-standing,curled and partially reduced graphene oxide network as sulfur host for high-performance lithium–sulfur batteries

Lithium–sulfur（Li–S） batteries have received more and more attention because of higher specific capacity and energy density of sulfur than current lithium–ion batteries. However, the low electrical conductivity of sulfur and its discharge product, and also the high dissolution of polysulfides restrict the Li–S battery practical applications. To improve their performances, in this work, we fabricate a novel free-standing, curled and partially reduced graphene oxide（CPrGO for short） network and combine it with sulfur to form a CPrGO–S composite as a cathode for Li–S battery. With sulfur content of 60 wt%, the free-standing CPrGO–S composite network delievers an initial capacity of 988.9 m Ah·g^（-1）. After 200 cycles,it shows a stable capacity of 841.4 m Ah·g^（-1） at 0.2 C, retaining about 85% of the initial value. The high electrochemical performance demonstrates that the CPrGO–S network has great potential applications in energy storage system. Such improved properties can be ascribed to the unique free-standing and continous CPrGO–S network which has high specific surface area and good electrical conductivity. In addition, oxygen-containing groups on the partially reduced graphene oxide are beneficial to preventing the polysulfides from dissolving into electrolyte and can mitigate the ＂shuttle effect＂.

Mapping and Candidate Gene Screening of Tomato Yellow Leaf Curl Virus Resistant Gene ty-5

To identify the inheritance pattern and perform fne mapping of ty-5 gene, P1, P2, F1, BC1 and F2 generations were obtained through a cross between CLN32120a-23 （containing ty-5 gene, P1） and S. lycopersicum Moneymaker （fully susceptible, P2）. The results showed that resistance of ty-5 gene was determined by a recessive effect. Meanwhile, it was presumed that another resistance gene might be involved in mediating the resistance to tomato yellow leaf curl virus （TYLCV）. In this study, fne mapping was used to map TYLCV resistance locus to an interval between NAC1 and TES2461 on the short arm of chromosome 4 with genetic distances of 0.5 and 0.8 cM, respectively. qRT-PCR results showed that four candidate genes, SlNAC1; LOC104229164; LOC101260925 and LOC101261508 having resistance-related expression patterns, were the likely target genes of ty-5. In addition, it was found that the codominant marker TES2461 could be used in marker-assisted selection （MAS） breeding. The fndings of this research provided the basis for future cloning of ty-5 gene as well as MAS breeding and plant resistance mechanism studies.

Minimizers of curl prescribed full trace

This paper concerns the minimization problem of L2 norm of curl of vector fields prescribed full trace on the boundary of a multiconnected bounded domain.The existence of the minimizers in H1 are shown by orthogonal decompositions of vector function spaces and a constructed auxiliary variational problem.And the H2 estimate of the type II divergence-free part of the minimizers is established by div-curl-gradient type estimates of vector fields.

Sweet Potato Leaf Curl Virus: Coat Protein Gene Expression in <i>Escherichia coli</i>and Product Identification by Mass Spectrometry

Sweet potato is one of the first natural GMOs, genetically modified 8000 years ago by Agrobacterium rhizogenes as reported recently by Kyndt et al. A section of 10 kbp long DNA (Transferred- DNA or T-DNA) of the Ri (Root-inducing) plasmid was transferred to the plant genome by A. rhizo-genes and has been maintained in all 291 hexaploid sweet potato cultivars of the world. The maintenance in the sweet potato genome and expression of two T-DNA genes for tryptophan-2-monooxygenease (iaaM) and for indole-3-acetamide hydrolase (iaaH) are likely to be physiologically significant since these enzymes convert tryptophan to indole-3-acetic acid, a major plant growth hormone auxin. Sweet potato (Ipomoea batatas (L.) Lam) is ranked the third most important root crop after potato and cassava, and the seventh in global food crop production with more than 126 million metric tons. Although sweet potato originated in Central or South America, China currently produces over 86% of world production with 109 million metric tons. In the United States, North Carolina is the leading producer with 38.5% of the 2007 sweet potato production, followed by California, Mississippi, and Louisiana with 23%, 19%, and 15.9%, respectively. Leaf curl virus diseases have been reported in sweet potato throughout the world. One of the causal agents is Sweet potato leaf curl virus (SPLCV) belonging to the genus Begomovirus (family Geminiviridae). Although SPLCV does not cause symptoms on Beauregard, one of the most predominant sweet potato cultivars in the US, it can reduce the yield up to 26%. Serological detection of SPLCV is not currently available due to the difficulties in obtaining purified virions that can be used as antigen for antiserum production. In attempts to obtain the coat protein (CP) of SPLCV for antibody production, primers were designed to amplify the CP gene. This gene was cloned into the expression vector pMAL-c2E as a fusion protein with maltose-binding protein, and transformed into Escherichia coli strain XL1-Blue. After gene induction, a fusion protein of 72 kDa was purified by amylose affinity chromatography. The yield of the purified fusion protein was approximately 200 μg/liter of bacterial culture. Digestion with enterokinase cleaved the fusion protein into a 42.5 kDa maltosebinding protein and a 29.4 kDa protein. The latter protein was identified by mass spectrometry analysis as the coat protein of SPLCV based on the fact that the mass spectrometry elucidated the sequences corresponding to 37% of amino acid positions of the SPLCV coat protein.

Generation and propagation of 21-day bottom pressure variability driven by wind stress curl in the East China Sea

Between June 2015 and June 2017,two pressure-recording inverted echo sounders(PIESs)and five current and pressure-recording inverted echo sounders(CPIESs)deployed along a section across the Kerama Gap acquired a dataset of ocean bottom pressure records in which there was significant 21-day variability(Pbot21).The Pbot21,which was particularly strong from July-December 2016,was coherent with wind stress curl(WSC)on the continental shelf of the East China Sea(ECS)with a squared coherence of 0.65 for a 3-day time lag.A barotropic ocean model demonstrated the generation,propagation,and dissipation of Pbot21.The modeled results show that the Pbot21 driven by coastal ocean WSC in the ECS propagated toward the Ryukyu Island Chain(RIC),while deep ocean WSC could not induce such variability.On the continental shelf,the Pbot21 was generated nearly synchronously with the WSC from the coastline to the southeast but dissipated within a few days due to the effect of bottom friction.The detection of Pbot21 by the moored array was dependent on the 21-day WSC patterns on the continental shelf.The Pbot21 driven southeast of the Changjiang Estuary by the WSC was detected while the Pbot21generated northeast of the Changjiang Estuary was not.