复苏植物旋蒴苣苔J结构域蛋白编码基因BhDNAJC2的 克隆、表达与功能

热激蛋白(HSP)是一类在受到逆境刺激后大量表达的蛋白质, 能够帮助蛋白质正确折叠, 促使变性蛋白质降解, 缓解逆境胁迫对生物体的损伤。为揭示热激蛋白在耐旱的复苏植物中的保护作用, 该研究对复苏植物旋蒴苣苔(Boea hygrometrica)HSP40家族中J结构域蛋白BhDNAJC2的编码基因进行了克隆、表达与功能分析。Real-time PCR检测表明, 该基因受脱水、低温、热激等多种逆境条件和脱落酸(ABA)诱导表达。BhDNAJC2-YFP定位于细胞质、内质网和细胞核。过表达BhDNAJC2的拟南芥(Arabidopsis thaliana)株系在干旱、热激、盐胁迫和碱胁迫下均表现出明显的抗逆性。综上所述, BhDNAJC2可能在旋蒴苣苔抗旱、耐热及耐盐碱等胁迫反应中起关键作用。     

复苏植物旋蒴苣苔棉子糖合酶基因的克隆和表达

复苏植物是研究植物耐脱水机制的特殊模式植物和宝贵的耐旱基因资源植物。以复苏植物旋蒴苣苔(Boea hygrometrica) 为材料研究其在脱水和复水过程中棉子糖系列寡糖含量的变化, 并克隆了旋蒴苣苔棉子糖合酶基因BhRFS。荧光定量PCR检测表明, BhRFS受干旱、低温(4°C)、高盐(200 mmol·L^–1NaCl)和ABA(100 μmol·L^–1)诱导表达上调, 而高温(37°C)抑制其表达, H₂O₂(200 μmol·L^–1)处理对其没有影响。研究结果表明, BhRFS可能参与了多种非生物逆境胁迫抗性反应, 并受到ABA依赖的信号通路调控。     

复苏植物旋蒴苣苔C2结构域小蛋白BhC2DP1参与植物对ABA的反应

为揭示植物抗旱的调控机理, 对复苏植物旋蒴苣苔(Boea hygrometrica)的一个编码C2结构域小蛋白的基因BhC2DP1进行研究。Real-time PCR和Pro_BhC2DP1:GUS报告基因检测显示, 该基因只在干旱早期和外源Ca²⁺处理0.5小时时受诱导表达; 分别施加Ca²⁺螯合剂EGTA和逆境激素ABA均抑制该基因表达, 但二者同时处理则显著诱导其表达, 表明ABA对该基因转录水平的调控是Ca²⁺依赖型的。过表达BhC2DP1的拟南芥(Arabidopsis thaliana)对ABA的敏感性增强, EGTA处理可消除其与野生型的差异, 表明Ca²⁺是BhC2DP1蛋白参与ABA反应所必需的。综上所述, ABA和Ca²⁺信号途径的精细调控可能是决定干旱诱导旋蒴苣苔中BhC2DP1基因表达时间、丰度和功能的重要机制。     

陕西宁强县苦苣苔科野生植物资源调查及分析

目的：基于第四次全国中药资源普查项目，对陕西宁强县域内苦苣苔科野生资源进行详细的调查。方法：通过野外样方调查，结合线路调查和重点区域调查，采集标本、鉴定物种及查阅相关文献，对县域内苦苣苔科植物资源汇总分析。结果：宁强县域内分布的苦苣苔科野生资源有6属8种，分别为直瓣苣苔（Ancylostemon saxatilis）、旋蒴苣苔（Boea hygrometrica）、大花旋蒴苣苔（B. clarkeana）、珊瑚苣苔（Corallodiscus Batalin）、降龙草（Hemiboea subcapitata）、纤细半蒴苣苔（H. gracilis）、白花金盏苣苔（Isometrum farreri）和吊石苣苔（Lysionotus pauciflorus）。其中直瓣苣苔、纤细半蒴苣苔和白花苣苔偶见，吊石苣苔一般，大花旋蒴苣苔和珊瑚苣苔少有分布，降龙草相对较多。它们具有广泛的科研和生态价值、药用价值和园林园艺观赏价值。结论：宁强县苦苣苔科野生资源比较丰富，种类较多，但个别种类分布区域狭小，种群逐年减少。因此，建议加强资源保护，同时积极开展种苗繁育基础研究工作。     

钙盐及模拟干旱互作对大花套唇苣苔种子萌发和幼苗生长的影响

苦苣苔科原大花旋蒴苣苔(former Boea clarkeana Hemsl.)为我国特有的复苏植物,在最近的修订中被并入套唇苣苔属(Damrongia Kerr),更名为大花套唇苣苔[D. clarkeana(Hemsl.)C. Puglisi]。为了探究该植物对喀斯特特殊生境的适应机制,该文以大花套唇苣苔成熟种子为材料,通过观察钙盐和模拟干旱互作试验,研究了干旱和盐胁迫共同作用对其种子萌发和幼苗生长的影响。结果表明:钙盐及模拟干旱互作时,低浓度钙盐可减轻干旱对种子萌发和幼苗生长的抑制作用,且低程度的干旱与低浓度的钙盐相互作用时反而会促进种子萌发和幼苗生长; 低钙盐低干旱复合条件对大花套唇苣苔生长的促进作用体现了该物种对喀斯特地区保水性差的石灰岩土壤基质的专适性,避免了和其他植物直接生态位的竞争。     

光照强度对大花旋蒴苣苔叶形态和生理指标的影响

以复苏植物大花旋蒴苣苔(Boea clarkeana)为盆栽实验材料,通过梯度遮光处理,研究不同光照强度(100%、80%、60%、40%和20%透光率)和不同处理时间(30、60、90、120和150d)对大花旋蒴苣苔叶生长指标和生理指标的影响。结果表明:随着光照强度的减弱,大花旋蒴苣苔叶的各生长指标(叶片长、叶片宽、叶柄长、叶柄直径以及叶面积)呈现先增大后减小的趋势,透光率为60%时达到最大值;全光照(100%透光率)时,大花旋蒴苣苔表现出明显的外伤症状,透光率为80%和20%时,分别表现出中度伤害和轻度伤害,透光率为40%和60%时,未出现明显的外伤症状;过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和过氧化物酶(POD)3种抗氧化酶活性均较低且随着光强减弱呈现先降低后升高的趋势,随着处理时间的延长呈先上升后下降的趋势,全光照时抗氧化酶的活性最大,透光率60%处理下酶活性相对较低;丙二醛(MDA)含量、脯氨酸(Pro)含量和质膜透性随着光强减弱呈先降低后升高的趋势,随着处理时间的延长显著升高;叶绿素含量随着光强减弱呈逐渐上升的趋势,随着处理时间的延长先降低后升高。分析表明,40%～60%的透光率有利于大花旋蒴苣苔的生长,强光和弱光对大花旋蒴苣苔的生长均不利。     

两种不同生境苦苣苔科植物的复苏特性及其对水分的光合和生理响应

复苏植物可以耐受极度干旱的环境,脱水至10％相对水分含量后仍然可以复苏.苦苣苔科植物包含有较多复苏植物,不同类群的复苏机理可能存在差异.该文选择分布在亚热带和温带石灰岩地区的锈色蛛毛苣苔(Paraboea rufescens)和心叶马铃苣苔(Oreocharis cordatula)两种苦苣苔科植物,并对这两个物种的叶...     

5种半蒴苣苔属植物光合特性的比较

对半蒴苣苔属( Hemiboea C. B. Clarke)植物半蒴苣苔( H. henryi C. B. Clarke)、贵州半蒴苣苔( H. cavaleriei H. Lév.)、疏脉半蒴苣苔( H. cavaleriei var. paucinervis W. T. Wang et Z. Y. Li ex Z. Y. Li)、华南半蒴苣苔( H. follicularis C. B. Clarke)和红苞半蒴苣苔( H. rubribracteata Z. Y. Li et Yan Liu)叶片的光合特性进行了分析和比较。结果表明：5种植物的光合参数及其日变化曲线、光响应参数〔(包括最大净光合速率( Pmax )、表观量子效率(AQY)、光补偿点(LCP)和光饱和点(LSP)〕、CO2响应参数〔包括CO2饱和净光合速率(CSPn)、羧化效率(CE)、CO2补偿点( CCP)和CO2饱和点( CSP)〕均有较大差异。半蒴苣苔、疏脉半蒴苣苔和红苞半蒴苣苔的净光合速率( Pn)日变化曲线均呈“单峰型”,而贵州半蒴苣苔和华南半蒴苣苔的Pn日变化曲线均呈“双峰型”且“午休”现象明显;贵州半蒴苣苔和疏脉半蒴苣苔的气孔导度( Gs)和蒸腾速率( Tr)日变化曲线均呈“单峰型”,而其他3种植物的Gs和Tr日变化曲线均类似“双峰型”;5种植物的胞间CO2浓度( Ci)日变化均呈先降后升的趋势;此外,5种植物的Pn与Gs均呈显著正相关、与Tr均呈正相关、与Ci均呈负相关。5种植物的光响应曲线和CO2响应曲线均有差异,但在光合有效辐射( PAR)低于200μmol·m-2·s-1或环境CO2浓度( Ce)低于800μmol·mol-1的条件下,它们的Pn均随PAR或Ce的升高急剧增加。5种植物中,贵州半蒴苣苔的Pmax最高,疏脉半蒴苣苔的CSPn最高;贵州半蒴苣苔的LCP最高(55.74μmol·m-2·s-1),其他4种的LCP均小于10μmol·m-2·s-1;5种植物的LSP均介于600~800μmol·m-2·s-1之间,CCP介于50~150μmol·mol-1之间,而CSP均在1000μmol·mol-1以上。研究结果揭示：供试5种植物均为阴生植物,但因产地生境及遗传特性差异使它们各自适应不同的光照条件,因而,在引种栽培过程中应根据各种类的光合特性采取适当的遮阳措施。     

大花旋蒴苣苔对脱水与复水的生理响应

本试验以陕西、四川(下称西部)、安徽和浙江(下称东部)4省区大花旋蒴苣苔(Boea clarkeana Hemsl.)的离体叶片为材料,通过对不同脱水时间(0、4、8、12、24和48 h)和脱水48 h后不同复水时间(4、8、12、24和48 h)条件下大花旋蒴苣苔生理指标变化的研究,比较了中国东部和西部地区大花旋蒴苣苔的耐脱水特性。结果表明:4种群大花旋蒴苣苔的相对含水量在脱水过程中呈显著下降趋势(P0.05);相对含水量下降的总体趋势表现为浙江种群安徽种群四川种群陕西种群;在复水过程中,4种群相对含水量基本恢复到实验前水平;超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)3种抗氧化酶活性以及MDA、脯氨酸、可溶性糖和可溶性蛋白的含量在脱水过程中均表呈显著上升趋势(P0.05),在复水过程中均呈显著下降趋势(P0.05)。通过对4种群生理指标的比较研究发现,4种群的耐脱水性整体表现为陕西种群四川种群安徽种群浙江种群,即西部种群的耐旱性强于东部地区。     

苦苣苔科植物远缘杂交亲和性初探

该研究对苦苣苔科的蛛毛苣苔属[Paraboea(C.B.Clarke)Ridley]、马铃苣苔属(Oreocharis Bentham)、报春苣苔属(Primulina Hance)、吊石苣苔属(Lysionotus D.Don)、台闽苣苔属(Titanotrichum Solereder)、半蒴苣苔属(Hemiboea C.B.Clarke)、长蒴苣苔属(Didymocarpus Wallich)、光叶苣苔属(Glabrella Mich.MollerW.H.Chen)进行属间远缘杂交,对马铃苣苔属的马铃苣苔组、川滇马铃苣苔组、大叶石上莲组进行组间远缘杂交,统计不同杂交组合的结实情况及播种后的种子萌发情况,以明确不同属(组)间远缘杂交亲和性,为通过远缘杂交进行苦苣苔科种质资源的创新奠定基础。结果表明:(1)不同属作为父本,与同一母本进行杂交,以及同一属内不同种作为父本,与同一母本进行杂交,结实情况差异显著。(2)不同属作为母本,与同一父本进行杂交,以及同一属内不同种作为母本,与同一父本进行杂交,结实情况同样存在显著差异。(3)相同两个种正反交杂交成功率也并不一致。(4)马铃苣苔属与半蒴苣苔属,报春苣苔属与吊石苣苔属,吊石苣苔属与报春苣苔属和半蒴苣苔属,光叶苣苔属与报春苣苔属和吊石苣苔属之间部分种进行远缘杂交能够正常结实,且杂交种子能够正常萌发。(5)马铃苣苔属内组间杂交无明显生殖隔离的现象。     

The early light-inducible proteins of barley. Characterization of two families of 2-h-specific nuclear-coded chloroplast proteins

Within 1-2 h of illumination of etiolated barley plants the mRNAs of seven nuclear-coded proteins are transiently induced. It is proposed that at least some of these proteins are precursors to chloroplast membrane proteins since after posttranslational transport 2-h-specific bands of 18.5 kDa, 18 kDa and 13.5 kDa have been found bound to thylakoid membranes. cDNA clones for these early light-inducible proteins (ELIPs) have been isolated. Hybrid-release translation shows that part of their information must be homologous since the complete set of early light-inducible translation products is obtained with all investigated clones although the proportions of the translated bands vary for individual clones. From hybridization data it is concluded that two ELIP families of high (24-27 kDa) and of low (16-18 kDa) molecular mass exist which are induced in parallel. Induction of ELIPs occurs even at very low light intensities and is saturated at about 1000 lx. Therefore, ELIPs are not considered to represent light stress proteins but to play a regulatory role during development.     

CBL1, a calcium sensor that differentially regulates salt,drought, and cold responses in Arabidopsis

Although calcium is a critical component in the signal transduction pathways that lead to stress gene expression in higher plants, little is known about the molecular mechanism underlying calcium function. It is believed that cellular calcium changes are perceived by sensor molecules, including calcium binding proteins. The calcineurin B-like (CBL) protein family represents a unique group of calcium sensors in plants. A member of the family, CBL1, is highly inducible by multiple stress signals, implicating CBL1 in stress response pathways. When the CBL1 protein level was increased in transgenic Arabidopsis plants, it altered the stress response pathways in these plants. Although drought-induced gene expression was enhanced, gene induction by cold was inhibited. In addition, CBL1-overexpressing plants showed enhanced tolerance to salt and drought but reduced tolerance to freezing. By contrast, cbl1 null mutant plants showed enhanced cold induction and reduced drought induction of stress genes. The mutant plants displayed less tolerance to salt and drought but enhanced tolerance to freezing. These studies suggest that CBL1 functions as a positive regulator of salt and drought responses and a negative regulator of cold response in plants.     

Genome-wide analysis of the family of light-harvesting chlorophyll a/b-binding proteins in arabidopsis and rice

Light-harvesting antenna system possesses an inherent property of photoprotection. The single-helix proteins found in cyanobacteria play role in photoprotection and/or pigment metabolism. The photoprotective functions are also manifested by the two- and four-helix proteins. The photoprotection mechanism evolved earlier to the mechanism of light-harvesting of the antenna complex. Here, the light-harvesting complex genes of photosystems I and II from Arabidopsis are enlisted, and almost similar set of genes are identified in rice. Also, the three-helix early light-inducible proteins (ELIPs), two-helix stress-enhanced proteins (SEPs) and one-helix high light-inducible proteins [one-helix proteins (OHPs)] are identified in rice. Interestingly, two independent genomic loci encoding PsbS protein are also identified with implications on additional mode of non-photochemical quenching (NPQ) mechanism in rice. A few additional LHC-related genes are also identified in rice (LOC_Os09g12540, LOC_Os02g03330). This is the first report of identification of light-harvesting complex genes and light-inducible genes in rice.Key words: Lhca and Lhcb proteins, Lhc proteins evolution, light-inducible proteins, protein alignment, PsbSThe light-harvesting proteins are present in different taxa. The proteins of light-harvesting systems from higher plants, cyano-bacteria, purple bacteria and green sulphur bacteria share no sequence similarity however little structural similarity can be seen.¹ Apparently, the light-harvesting systems in these different taxa might have evolved independently from each other.¹ To enable efficient transfer of excitation energy into the reaction centers, where charge separation takes place, different proteins are recruited in order to coordinate the photosynthetic pigment molecules. The light-harvesting and light dissipation are tightly coupled processes involving the higher plant light-harvesting antenna. Here, genome-wide analysis of the light-harvesting chlorophyll a/b-binding proteins and light-inducible proteins in Arabidopsis thaliana L. and Oryza sativa L. (rice) is conducted. This study wherein genes coding for antenna proteins are identified and named can be used as a nomenclature guide to the light-harvesting complex gene family members and their relatives in rice.     

小麦ARF基因家族生物信息学分析及在干旱胁迫下的表达特性研究

植物生长素响应因子ARF(auxin response factor)参与调节了植物的向性运动、顶端优势、微观的分化、侧根和茎的形态发生等众多生理反应,在植物生长发育的整个过程都起到重要调控作用。本研究通过对小麦最新基因组数据进行分析,获得了61个ARF家族基因,命名为TaARFs,根据染色体编号排列为TaARF1~TaARF61,对61个TaARFs基因进行系统生物信息学分析后发现ARF家族基因结构较为复杂,外显子数量从1个到15个变化不等,除了4号染色体和5A和5B染色体之外,其余的染色体均有ARF家族基因分布。ARF家族基因大多包含B3 DNA结构域、ARF结构域(Auxin-resp)和Aux/IAA结构域;同源进化分析表明,小麦ARF家族基因的旁系同源基因数量明显多于大麦和二穗短柄草。通过拟南芥数据库比对获得14个高同源的根系发育相关的小麦ARF家族基因,利用二系杂交小麦京麦6号及父母本根系为试材进行干旱胁迫处理及实时荧光定量PCR(qPCR)筛选。结果表明,7个小麦ARF基因不同程度受到干旱胁迫诱导,其在旱胁迫下的表达量显著高于正常条件下的表达量,可能参与干旱胁迫应答;此外本研究还发现,ARF基因在F1杂交种中表达量显著高于双亲,表现出超亲表达模式,可能参与了根系抗旱杂种优势基因表达调控网络。     

Heavy metal stress-inducible early light-inducible gene CaELIP from hot pepper (Capsicum annuum) shows broad expression patterns under various abiotic stresses and circadian rhythmicity

An early light-inducible protein gene (CaELIP) was isolated from a cDNA library of hot pepper (Capsicum annuum) that showed heavy metal stress-inducible expressions. This gene contains an open reading frame (ORF) encoding a protein of 160 amino acids, and the protein has significant homology with reported early light-inducible proteins from other plant species. Topology analysis for CaELIP suggested three transmembrane domains. Genomic DNA blot analysis showed that CaELIP is a single copy gene in hot pepper. The treatment of seedling roots of hot pepper with Cu induced ROS generation in the root, and the level of ROS generation was paralleled to the concentration of Cu that again was matched to the increase in the CaELIP expression level. Results suggested that expression of CaELIP can be induced by the ROS generated by the excessive Cu in the plant. Exogenous SA treatment significantly alleviated Cu-induced expression of CaELIP, while exogenous JA treatment aggravated expression of CaELIP under Cu stress. CaELIP showed a transient expression when exposing the plant to light for 1 h. CaELIP also showed an endogenous circadian rhythmicity with high expression level in the morning and decreased expression level thereafter. The expression of CaELIP was also induced by high or low temperature, high salinity, drought, and stress hormone ABA. Taken together, the results suggest that CaELIP would function in responding to environmental signals and possibly regulating the response to the abiotic stresses that can be related to the abiotic stress tolerance in plants.