作物海藻糖合成相关基因的研究进展

海藻糖是一种非还原性二糖,广泛存在于自然界各种生物中。随着海藻糖代谢途径的发现,人们逐渐重视对海藻糖及其中间产物海藻糖-6-磷酸（trehalose 6-phosphate,T6P）的研究。T6P是糖信号重要标志,也是植物生长发育必不可少的组成部分。海藻糖-6-磷酸合成酶（trehalose-6-phosphate synthases,TPS）催化T6P的生成,然后在海藻糖-6-磷酸磷酸酶（trehalose-6-phosphate phosphatase,TPP）催化作用下发生去磷酸化反应生成海藻糖。海藻糖合成相关基因在植物生长发育、逆境调控中具有重要作用,本文对海藻糖合成及作物中相关基因的功能进行了总结。     

陆地棉小GTP结合蛋白基因GhROP6的克隆及表达初步分析

为探究ROP基因在棉花抵御逆境胁迫中的生物学功能,利用同源克隆的方法获得一个陆地棉GhROP6基因,通过生物信息学方法分析其理化性质、结构及进化关系,利用实时荧光定量PCR(qRTPCR)技术探究GhROP6基因的组织表达特异性及不同逆境胁迫和外源激素处理下的表达模式,构建GhROP6基因的VIGS载体并转化棉花,利用qRT-PCR技术检测其沉默效率。结果显示,GhROP6基因开放阅读框（ORF）为597 bp,编码一个含198个氨基酸的I类ROP蛋白;多重序列比对结果显示,GhROP6符合ROP蛋白结构特征,且与其他物种ROP蛋白高度同源;进化树分析结果显示GhROP6蛋白与拟南芥AtROP6蛋白同源性最高;GhROP6基因在棉花根、茎、真叶及子叶中均有表达,且在真叶中表达量最高;GhROP6基因对干旱、高盐、低温、高温等胁迫和外源脱落酸（ABA）、生长素（IAA）处理均有不同程度的响应,可能在棉花抗逆反应中扮演着重要角色。GhROP6在棉花的叶片和根部均得到有效沉默,表明已获得GhROP6基因沉默植株。本研究为进一步了解GhROP6基因的分子生物学功能奠定了基础。     

谷子CIPK基因(Seita.5G145900)对非生物逆境的响应

在谷子基因组中鉴定出一个CIPK(Seita.5G145900,命名为SiCIPK19)基因。为揭示SiCIPK19对逆境胁迫的响应,对其基因结构、蛋白特征、功能、进化等性状进行了系统的分析和预测,并用实时定量PCR(RT-qPCR)检测了其在谷子苗期不同逆境及关键生育期干旱胁迫下的表达。结果表明,SiCIPK19基因位于谷子5号染色体,基因组序列长1 353 bp,编码450个氨基酸,基因无可变剪切,且不含内含子。功能域分析和多序列比对发现,SiCIPK19蛋白具有非常保守的序列结构,与其他植物CIPK蛋白也非常相似。RT-qPCR分析表明,SiCIPK19基因被聚乙二醇6000(PEG 6000)、ABA、高盐和低温胁迫强烈诱导。此外,SiCIPK19基因在谷子拔节期、抽穗期和灌浆期干旱条件下参与了对干旱胁迫的响应,推测该基因参与谷子对非生物逆境的应答,尤其在抽穗期和灌浆期干旱胁迫应答中发挥重要作用。本研究结果为进一步分析CIPK基因逆境应答机制,以及利用基因工程方法改善谷子抗逆性和提高产量提供了理论支持。     

巴西橡胶树HbNAC1基因启动子的克隆及序列分析

NAC转录因子是植物特有的一类转录调控因子,在植物的生长发育、激素调节和境胁迫应答中具有重要的功能。为研究NAC转录因子在巴西橡胶树（Hevea brasiliensis）抗逆胁迫中的功能,本项目组根据巴西橡胶树NAC转录因子-HbNAC1基因序列,通过Genome Walking方法从巴西橡胶基因组DNA中获得了长度为1861bp的HbNAC1基因的5＇调控区片段,序列分析表明该段序列含有一个典型的真核生物核心启动子区域,转录起始位点T位于起始密码子上游52bp处。该启动子序列除了含有TATA-box、CAAT-box等基本顺式作用元件外,还具有茉莉酸响应元件以及大量光顺式作用元件和逆境胁迫诱导相关的顺式调控元件,这表明HbNAC1基因在橡胶树逆境胁迫应答过程具有重要功能,其启动子可能是一个光诱导型和组织特异性启动子。     

逆境胁迫下植物MAPK级联反应途径研究新进展

MAPK级联反应途径是广泛存在于真核生物体内的信号传导途径,参与植物生长发育及对逆境胁迫的应答反应。目前已从植物中鉴定了多条MAPK级联反应途径以及多个MAPK级联途径激酶基因,但是对MAPK级联反应途径在逆境胁迫下作用机制的了解仍有很多不足。本文基于近年来国内外在基因组范围内对MAPK级联途径激酶基因的分析,介绍了植物基因组中MAPK级联途径激酶基因的数量和结构特点、激酶的结构特点、MAPK信号传导途径基因家族在逆境胁迫下的表达特性以及MAPK级联反应途径的研究方法等,以期为该领域的相关研究提供参考。     

玉米转录因子ZmBES1/BZR1-7基因克隆及功能分析

BES1/BZR1蛋白是油菜素内酯信号途径的唯一转录因子,在植物生长发育及逆境应答中发挥重要作用。为了探究玉米ZmBES1/BZR1-7基因的功能,从玉米自交系B73中克隆到ZmBES1/BZR1-7基因,并对其功能进行初步分析。序列分析结果表明,ZmBES1/BZR1-7基因无内含子,开放阅读框(ORF)长975 bp,编码324个氨基酸。ZmBES1/BZR1-7蛋白N端高度保守,包含bHLH结构域,与水稻OsBZR1-1相似性达75.95%。实时荧光定量PCR结果表明,ZmBES1/BZR1-7在玉米叶和根中的表达受渗透与盐胁迫诱导显著;16% PEG-6000和100 mmol·L^-1 NaCl处理12 h,叶片中ZmBES1/BZR1-7表达量分别为对照的17.8倍和19.8倍。酵母激活试验结果表明,ZmBES1/BZR1-7蛋白具有转录激活活性。共相关分析结果表明,玉米中有72个基因与ZmBES1/BZR1-7基因的表达相关性较高,启动子区均含有E-box或BRRE元件,推测可能是ZmBES1/BZR1-7转录因子调控的靶基因,主要参与细胞、细胞组分、细胞代谢过程等。本研究结果为深入解析玉米ZmBES1/BZR1-7的功能及其调控网络奠定了基础。     

水稻蜡质合成相关基因OsGL1-5的表达模式及逆境响应特征分析

通过生物信息学方法对水稻蜡质合成相关基因OsGLl-5启动子序列特点进行分析;并以水稻中花11不同组织和发育时期的穗子为材料,通过半定量RT-PCR及mRNA原位杂交技术分析OsGLl-5的时空表达特征;同时,分别以200mmol·L-1 NaCl、100μmol· L-1 ABA和1.0％ H2O2处理水稻幼苗,通过半定量RT-PCR分析逆境胁迫下OsGL1-5的表达模式.生物信息学分析表明,OsGL1-5启动子中包括大量与干旱、冷、盐等多种逆境胁迫相关的调控序列.时空表达特征分析表明,OsGL1-5主要在不同发育时期的穗子中表达,且表达部位集中在稃片的毛状体和花药绒毡层中,叶中表达量相对较低,而茎和根中没有检测到表达.NaCl、ABA以及H2O2等逆境胁迫下,OsGL1-5表达量在不同处理时间有所增加.     

玉米乙烯应答元件结合蛋白基因启动子克隆与功能验证

为了给玉米转基因研究提供更多的非生物逆境诱导启动子,寻找只在逆境胁迫条件下适当驱动外源抗逆基因的表达,在生物信息学分析的基础上,克隆与水稻DREB1B转录因子基因同源的玉米乙烯应答元件结合蛋白基因sb CBF6的启动子psb CBF6,在非生物逆境应答元件分析和实时定量PCR验证其非生物逆境胁迫响应特性后,用以构建驱动报告基因GUS的表达载体,并使用基因枪法转化玉米愈伤组织,通过愈伤组织的GUS荧光值与荧光素酶发光值的比值,评价psb CBF6启动子在非生物逆境胁迫及激素诱导条件下的驱动活性。结果表明,sb CBF6基因在各种非生物逆境胁迫下差异表达。psb CBF6启动子长1 479 bp,存在多种与非生物逆境胁迫应答相关的调控元件,可在非生物胁迫条件下驱动外源抗逆基因在转基因植物中诱导表达。试验结果为研究抗逆转基因玉米提了供参考。     

谷子GRAS转录因子家族的全基因组鉴定、表达分析及标记开发

为了鉴定谷子GRAS家族基因并揭示SiGRASs响应外源植物激素和逆境胁迫过程的表达规律,本研究采用生物信息学方法对谷子GRAS转录因子家族进行全基因组鉴定,利用实时荧光定量PCR(qRT-PCR)进行4种激素和2种胁迫处理后的表达分析,并根据SiGRAS23序列差异开发分子标记。结果表明,谷子全基因组共包含52个GRAS转录因子基因,大部分编码亲水性蛋白;82.69%的基因编码酸性蛋白,长度为362~734 aa,分子量为39.81~100.09 kDa,等电点为4.85~9.53。系统发育分析将谷子GRAS家族划分为10个亚家族。组织表达量分析表明,各亚族基因具有明显的组织表达特异性,LISCL、DELLA和SHR亚族基因分别在叶、茎和根中有较高的表达量,PAT1和HAM亚族大部分基因为组成型表达,但在叶中的表达量最高。SiGRASs启动子区含有多种植物激素、逆境响应相关的顺式作用元件;qRT-PCR结果显示,SiGRASs在不同激素和非生物胁迫下的表达水平存在较大差异,其中PAT1亚族中Seita.2G369400对6种不同的处理响应最为敏感;少数SiGRASs基因在各组织和各种激素和非生物胁迫处理下,表达量均在极低水平。DELLA亚族中的SiGRAS23在遗传群体AJF₅的双亲矮宁黄和晋谷21号间存在序列差异,据此开发的分子标记D8-1与该群体株高性状紧密连锁。本研究为解析谷子GRAS家族基因参与激素信号转导及逆境胁迫响应的功能研究奠定了基础,SiGRAS23的分子标记可用于今后谷子种质资源株高等位变异的筛选。     

番茄SlMAPK9-2基因分离及表达分析

促分裂原活化蛋白激酶(MAPK)信号途径在植物生长发育以及多种逆境胁迫响应和激素调控过程中发挥着至关重要的作用。为了研究MAPK基因的结构和功能,利用生物信息学分析以及PCR扩增方法从番茄中分离了1个新的MAPK基因,克隆其c DNA全长序列,命名为Sl MAPK9-2;利用NCBI数据库Blast P工具和在线软件MEME分析发现其具有MAPK保守的结构域和保守基序。系统进化树分析显示Sl MAPK9-2属于D组MAPK,与茄科植物马铃薯和烟草MAPK9位于同一进化树分支。利用数据库PGDD分析发现,Sl MAPK9-2与Sl MAPK16以及Pm MAPK9之间发生了大片段复制事件,且2个基因对的Ka/Ks均小于1,说明经历了达尔文纯化选择。实时荧光定量PCR分析发现,Sl MAPK9-2在不同组织器官中均有表达,在开放花中表达量最高。非生物逆境(高温和盐胁迫)和外源激素(脱落酸和水杨酸)处理可以显著改变Sl MAPK9-2的表达水平。启动子预测分析也发现,Sl MAPK9-2启动子区含有大量响应病原菌、激素、高温及脱水的顺式作用元件。综上,Sl MAPK9-2可能在番茄逆境胁迫应答中发挥重要调控作用。本研究为进一步探索Sl MAPK9-2的生物学功能及作用机制奠定了基础。     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Biodiversity and ecogeography of wild Lactuca spp. in some European countries

Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.     

Properties of anaerobically digested and composted municipal solid waste assessed by linking soil mesofauna dynamics and nitrogen modelling

We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Variation in quality parameters between and within 14 Nordic tree fruit and berry species

Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.     

Potassium Fixation and Release Characteristics in Rhizosphere and Nonrhizosphere Soils for a Rapeseed–Rice Cropping Sequence

Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L^?1 nitric acid (HNO₃) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L^?1 ammonium acetate (NH₄OAc) and 1.0 mol L^?1 HNO₃ extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils.