盐地碱蓬耐盐相关基因克隆研究进展

盐地碱蓬是一种生长于盐碱地和海滨沙滩的盐生植物,富含氨基酸、维生素、矿物质等,极具开发价值。由于其具有很强的耐盐性,人们日益重视其耐盐机理的研究。目前对其耐盐机理的研究已经进入到耐盐基因的克隆、结构分析、功能研究等方面。综述了近年来盐地碱蓬与耐盐相关的基因克隆、结构及功能分析等方面的研究进展。     

盐胁迫下3种滨海盐生植物的根系生长和分布

我国广大滨海地区的盐土上发育着大量的盐生植物,这些植物的根系对维持土壤稳定性,减小风蚀和水蚀具有重要作用。在水培条件下,针对碱蓬、盐角草和盐地碱蓬3种滨海盐生植物,研究它们在不同盐浓度条件下根系分布的差异。结果表明:一定浓度的盐分可以促进3种盐生植物生长,但较高浓度的盐抑制其生长,特别是对根系生长的抑制作用更大。在同样盐浓度下,盐地碱蓬的生长最快,生物量也最大。在盐分浓度较低时,3种盐生植物的主根长和总根长都有所增加,与对照相比,盐角草增加的幅度较大,但高浓度的盐会抑制根系总长度的增加,其中盐角草较碱蓬和盐地碱蓬抑制的程度轻。盐分对3种植物的根系平均直径没有显著的影响,但有减小的趋势。在水培条件下,碱蓬和盐角草的根系上、中、下部分布的较均匀,而盐地碱蓬的根系中部比上部和下部有显著的增加,盐分对每种植物的根系的分布没有显著的影响。从根系的分布特征可以推断:盐角草比碱蓬和盐地碱蓬具有较强的抗盐性和耐瘠薄能力;碱蓬的耐盐能力较其它两种植物差,盐角草的耐盐性最强。根据3种滨海盐生植物的根系生长和分布特征,证明这3种植物的根系分属于2种功能型,碱蓬是浅根系功能型,盐角草和盐地碱蓬是深根系功能型。根系分布的参数表明3种滨海盐生植物中盐地碱蓬是用来加强土壤稳定性最好的植物。     

8种盐生植物种子萌发特征与NaCl盐度的关系

耐盐植物的选育是盐渍土地生物改良的关键。通过对13个NaCl盐度梯度下，真盐生植物囊果碱蓬、盐地碱蓬、高碱蓬、盐角草、盐爪爪，泌盐植物大叶补血草、耳叶补血草、黄花补血草8种盐生植物的萌发试验，测定其种子发芽率、发芽势、发芽指数和相对盐害率等指标，研究不同NaCl盐度胁迫对其萌发特性的影响。结果表明：低盐度（50 mmol/L）能促进8种盐生植物的萌发；随着盐度的上升，盐角草、盐地碱蓬、囊果碱蓬、高碱蓬表现出较强的萌发耐盐性，发芽势和发芽指数优于其他植物；盐角草的萌发耐盐性最佳，在1000 mmol/L盐度下萌发率仍能达到54.0%。进一步通过S型生长曲线和线性模型分析得出，8种植物为对抗逆境大致分为"快速型"和"缓慢型"两种萌发策略；随盐度的升高，初始萌发时间和萌发高峰时间均不同程度的向后推迟。盐度≤200 mmol/L时，囊果碱蓬的萌发占据优势，其萌发速率大于其他植物，且差异显著；中盐度400 mmol/L左右时，盐地碱蓬和盐角草萌发最快，二者无显著差异；盐度≥600 mmol/L时，盐角草萌发速率较快，相比其他植物差异显著。泌盐植物的萌发耐盐适宜浓度和耐盐极限浓度均低于真盐生植物。8种植物均有作为氯化物为主盐渍土地区生物改良材料的潜力。     

碱蓬属植物耐盐机理研究进展

碱蓬属(Suaeda)植物是一类典型的真盐生植物,属于重要的盐生植物资源,全球广泛分布.人们已经对20种碱蓬属植物进行了观察和盐胁迫实验,研究了不同器官或组织的生理生化特征及其对盐胁迫的反应,并基于这些研究分析了盐胁迫的应答机制.叶片肉质化、细胞内离子区域化、渗透调节物质增加和抗氧化系统能力增强是碱蓬属植物响应和适应盐胁迫的重要方式和途径.但迄今为止的研究工作尚有一定的局限性,主要包括:研究工作主要集中在植物地上部分,而对植物地下部分的研究较少;多是少数生物学指标或生理学现象的单独观察,而缺乏对生理代谢过程的整体和综合分析;针对某种碱蓬的独立分析较多,而与近缘种的比较研究较少;植物对中性盐胁迫的反应研究较多,而对碱性盐的研究较少.为进一步系统阐明碱蓬属植物的耐盐机制,今后的工作应注重碱蓬属植物响应和适应盐胁迫的信号网络和调控机制研究,基于系统生物学研究思路,采用现代组学技术探索该属植物响应盐胁迫的由复杂信号网络调控的特殊生理特征和特异代谢途径.     

藜科盐生植物的形态特征与耐盐分子机理研究进展

在非生物环境胁迫因子中,盐胁迫是造成农作物减产的主要因素之一.从藜科植物耐盐的形态生理学机制和分子生物学角度入手,讨论了藜科植物耐盐基因工程的新进展,探讨藜科盐生植物的盐胁迫机理,为利用基因工程手段培育耐盐植物奠定基础.     

真盐生植物盐地碱蓬资源特征与利用开发研究进展

盐地碱蓬为藜科碱蓬属一年生真盐生植物,能适应特殊的盐碱生境,具有典型的摄盐性和集积特征及种子二型性.本研究简要介绍了盐地碱蓬的生物学特性,重点概述了盐地碱蓬在盐碱地、重金属污染、石油污染、水体污染等生态价值,系统地综述了在食用蔬菜、黄酮类和多糖类、食用油和生物柴油、色素、膳食纤维、植物盐和植物碱、新型饲料和饲料添加剂、...     

植物耐盐基因工程研究进展

盐害是影响植物生长和作物产量的主要因素之一。用于提高植物耐盐性的基因工程方法很多,最常见的就是在植物中过量表达抗盐相关的功能基因,包括植物信号传导蛋白基因、植物离子通道蛋白基因和合成小分子渗透剂的酶基因等。归纳了近年来植物耐盐基因工程的研究进展,并展望了植物耐盐基因工程的研究前景。     

盐地碱蓬叶片液泡膜H^＋—ATPase B亚基的克隆及盐胁迫下表达分析

植物液泡膜H^ -ATPase在建立跨液泡膜质子梯度、促进液泡Na^ 区域化、提高植物耐盐性方面发挥着重要作用。本实验从盐生植物盐地碱蓬(Suaeda salsa L.)cDNA文库分离到碱蓬叶片液泡膜H^ -ATPase B亚基cDNA克隆。测序表明该基因长达1974bp,开放阅读框有1470bp编码489个氨基酸,含有一个保守的ATP结合位点,其蛋白分子量约为54．29kD。Northern及Western印迹表明盐地碱蓬液泡膜H^ -ATPase B亚基表达明显受NaCl胁迫诱导,并且在NaCl胁迫下,B亚基在转录及翻译水平上与液泡膜H^ -ATPase c亚基存在协同作用。盐胁迫下,盐地碱蓬液泡H^ -ATPase B亚基与c亚基的协同表达增加了液泡H^ -ATPase的数量,从而提高了液泡H^ -ATPase活性,为碱蓬叶片液泡Na^ 区域化提供了动力,最终提高了碱蓬植株的耐盐性。     

盐地碱蓬叶片液泡膜H+-ATPase B亚基的克隆及盐胁迫下表达分析

植物液泡膜H -ATPase在建立跨液泡膜质子梯度、促进液泡Na 区域化、提高植物耐盐性方面发挥着重要作用.本实验从盐生植物盐地碱蓬(Suaeda salsa L.)cDNA文库分离到碱蓬叶片液泡膜H -ATPase B亚基cDNA克隆.测序表明该基因长达1 974 bp,开放阅读框有1 470 bp编码489个氨基酸,含有一个保守的ATP结合位点,其蛋白分子量约为54.29 kD.Northem及Western印迹表明盐地碱蓬液泡膜H -ATPase B亚基表达明显受NaCl胁迫诱导,并且在NaCl胁迫下,B亚基在转录及翻译水平上与液泡膜H -ATPase c亚基存在协同作用.盐胁迫下,盐地碱蓬液泡H -ATPase B亚基与c亚基的协同表达增加了液泡H -ATPase的数量,从而提高了液泡H -ATPase活性,为碱蓬叶片液泡Na 区域化提供了动力,最终提高了碱蓬植株的耐盐性.     

黄河三角洲地区耐盐乡土植物种类及生态价值研究

描述了黄河三角洲地区耐盐乡土植物的种类及生态价值。黄河三角洲地区耐盐乡土植物以草本植物为主,灌木和乔木零星分布。主要耐盐乡土植物有芦苇、盐地碱蓬、柽柳和旱柳等。黄河三角洲地区耐盐乡土植物发挥着重要的生态作用,主要包括:防风固沙,保持水土,调节气候;固碳增汇,补偿碳排放;防治重金属等污染;净化水质;维持生物多样性;改良盐渍土。     

Observations on the Symgenesis and Dynamic Changes of Coastal Solonchak Vegetation at Jiangsu

This preliminary study attempts to make an approach to the symgenesis and dynamic changes of the hylophytic vegetation on coastal line, in general. By analysing the materials from various sources, and obtained by our own observations, the results are briefly summarized as follows: (1) The coastal solonchak vegetation along the shore line of Yellow Sea, bordering the east coast of Kiangsu province, within the warm temperate and the subtropical zones, is composed of many obligate halophtes, such as Salieornia europaea, Suaeda salsa, Suaeda glauca, etc. and some facultative hylophtes, such as Artemisia capillaris, Sonchus arvensis, Lepidium viginicum, etc., These species are naturally grouped in various plant communities frequently as belts, and responsible to differant salt concentrations and moisture. The distribution of a halophytic community generally appears to be limited by the salinity of soil. (2) Coastal solonehak phytocoenosim may be divided into following two main classes: 1. The primary seral communitis, which are generated and developed mainly on the primary bare area, contain 9 communities, such as Suaeda salsa community, Zoysis macrostachys community, etc. 2. The secondary seral communities, which are generated and developed mainly on the secondary bare area, contain 6 communities, such as Suaeda glauca community, Artemisia capillaris community, etc. (3) It is evident that the symgenesis and formation of coastal solonchak vegetation are in accordance with the course of the development of coastal solonchak. (4) Vegetational succession on coastal solonchak is caused by the decreasing salt content and increasing humus content of soil. In this paper, diagrams of successional dynamic changes have been prepared to show their close relationship between the hylophytic vegetation and the solonchak on coastal regions.     

盐地碱蓬亲环素CYP1基因的克隆、表达及耐盐性分析

为探索盐地碱蓬亲环素与其耐盐性的关系,使用RT-PCR和RACE完成盐地碱蓬亲环素基因的全长克隆与测序,并命名为SsCYP-1.SsCYP-1基因全长为875 bp,编码区为531 bp,编码176个氨基酸.多重序列BLAST结果表明,SsCYP-1基因可归于亲环素家族,并具有特定的肽酰脯氨酸顺反异构酶活性结构域特征.为验证盐地碱蓬亲环素的耐盐特性,构建了SsCYP-1表达载体并在大肠杆菌（E.coli） BL21 （Rosetta）中通过IPTG诱导表达,通过PAGE检测目的蛋白为19 KD,与Editseq软件预测的目的蛋白大小基本一致.对重组菌PET-Ss-CYP1进行耐盐分析表明其在高盐浓度培养下生长速度远高于对照菌pETDuet-1.据此,推测该基因在盐地碱蓬生长中可能具有相关的耐盐性作用.     

Expressed sequence tags from a NaCl-treated Suaeda salsa cDNA library

Past efforts to improve plant tolerance to osmotic stress have had limited success owing to the genetic complexity of stress responses. The first step towards cataloging and categorizing genetically complex abotic stress responses is the rapid discovery of genes by the large-scale partial sequencing of randomly selected cDNA clones or expressed sequence tags (ESTs). Suaeda salsa, which can survive seawater-level salinity, is a favorite halophytic model for salt tolerant research. We constructed a NaCl-treated cDNA library of Suaeda salsa and sequenced 1048 randomly selected clones, out of which 1016 clones produced readable sequences (773 showed homology to previously identified genes, 227 matched unknown protein coding regions, 16 anomalous sequences or sequences of bacterial origin were excluded from further analysis). By sequence analysis we identified 492 unique clones: 315 showed homology to previously identified genes, 177 matched unknown protein coding regions (101 of which have been found before in other organisms and 76 are completely novel). All our EST data are available on the Internet. We believe that our dbEST and the associated DNA materials will be a useful source to scientists engaging in stress-tolerance study.     

翅碱蓬对镉的耐性及吸收特性的研究

重金属Cd具有高毒性, 对生物体危害较大。盘锦红海滩优势物种翅碱蓬能够吸收一定量的重金属, 因此可用于湿地滩涂污染的原位修复。通过水培的方法, 以翅碱蓬为研究对象, 测定不同浓度Cd胁迫下翅碱蓬的根长、苗高、鲜重、叶绿素含量、及根、茎、叶内Cd的含量, 探讨Cd对于翅碱蓬生长发育的影响以及对Cd的吸收规律。结果表明: 低浓度Cd对翅碱蓬的根长和苗高起到促进作用, 而低浓度 Cd对翅碱蓬根长和苗高生长起到抑制; 无论低浓度还是高浓度, 对翅碱蓬鲜重均具有一定的抑制作用, 抑制强弱表现为20 μg·L-1浓度组>1 μg·L-1浓度组。不同Cd浓度下翅碱蓬叶绿素含量表现为“低促高抑”; 植物各个部位对于Cd的吸收为地下部分>地上部分。     

碱蓬cDNA表达文库的构建

以盐生植物盐地碱蓬（Suaeda salsa)地上部分为材料,提取植物总RNA,纯化出mRNA,合成cDNA第一链,得到双链cDNA后,连接入植物表达载体,构建cDNA表达文库。该文库重组子约10^6。将该文库转化农杆菌GV3101,可直接用以转化拟南芥。     

Organ-Specific Responses of Vacuolar H~+-ATPase in the Shoots and Roots of C_3 Halophyte Suaeda salsa to NaCl

Suaeda salsa L. is a halophytic species that is well adapted to high salinity. In order to understand its salt tolerance mechanism, we examined the growth and vacuolar H+-ATPase (V-ATPase) response to NaCl within the shoots and roots. The growth of shoots, but not roots, was dramatically stimulated by NaCl. Cl? and Na+ were mainly accumulated in shoots. V-ATPase activity was significantly increased by NaCl in roots and especially in shoots. Interestingly, antisera ATP95 and ATP88b detected three V1 subunits...     

种植盐地碱蓬改良滨海盐渍土对土壤微生物区系的影响

利用盐生植物盐地碱蓬对天津河口滨海盐碱地进行生物修复,研究了其对土壤微生物区系的影响.结果表明,种植区碱蓬根系土壤的可溶性盐分与对照土壤相比下降了41%（重量法）和37%（电导法）;根系土壤的微生物数量明显增加,其中细菌、放线菌和真菌分别较对照增加了2.3倍、4.3倍和71倍,与对照相比均为显著性差异.根系微生物的耐盐性结果显示,随着土壤盐分的降低,根系微生物生长的最适盐度也随之降低,耐盐性较低的微生物种群已逐渐成为优势种群.系统发育分析表明,枯草杆菌属成为植物修复后土壤中的优势种群.     

Ecological thresholds of Suaeda salsa to the environmental gradients of water table depth and soil salinity

The responses of Suaeda salsa to the environmental gradients of water table depth and soil salinity in the Yellow River Delta, China were analyzed from the aspect of ecological thresholds which were developed from the Gaussian model. Based on the correlation analysis of population biomass, density, height, coverage and abundance of Suaeda salsa, population biomass was selected as the population index for further analysis. The results indicated that the optimum water table depth for the growth of Suaeda salsa was about ?0.42 m, the ecological thresholds were from ?0.92 m to 0.08 m, and the optimum ecological thresholds were from ?0.67 m to ?0.17 m. To the soil salinity gradient, the optimum was about 12.71 g/kg, the ecological thresholds were from 5.17 g/kg to 20.25 g/kg, and the optimum ecological thresholds were from 8.94 g/kg to 16.48 g/kg. However, the effect of water-salinity interaction seemed to be important to the growth of Suaeda salsa, which was discussed through analyzing the water table depth-soil salinity relationship and their interactions. By using Ward cluster analysis and Gamma distances, 69 sampling sites were classified into 7 kinds of Suaeda salsa communities. It was found that there was a remarkable response of the community structure of Suaeda salsa to the water table depth and soil salinity gradients, which can be a switchover from xeromorphic and saline-alkali plants to limnophytes, and vice versa.     

过量表达GST基因对盐胁迫下转基因拟南芥氧化损伤的影响

利用模式生物拟南芥作为实验材料,通过测定谷胱甘肽-抗坏血酸代谢相关酶（GST、GPX、APX、GR、DHAR、MDHAR）的活性和GSH、ASA、MDA含量以及生物量等来研究过量表达具有过氧化物酶活性的盐地碱蓬谷胱甘肽转移酶基因（GST基因）对盐胁迫下转基因拟南芥氧化损伤的影响。结果显示,转基因拟南芥比野生型具有较高的GST、GPX以及MDHAR酶活性;前者还具有较多的还原型谷胱甘肽和抗坏血酸,并且谷胱甘肽库氧化水平较野生型高。盐胁迫不但部分抑制了野生型拟南芥的生长,同时也导致了大量脂质过氧化物的积累;而盐胁迫对转基因拟南芥的生长抑制不明显,也没有较多的脂质过氧化物的积累。结果表明,过量表达盐地碱蓬谷胱甘肽转移酶基因提高．广转基因拟南芥依赖于还原型谷胱甘肽的过氧化物清除途径,同时有可能改变了GSH和ASA的代谢途径,这两方面的作用导致了转基因拟南芥氧化损伤的降低,使转基因拟南芥在盐胁迫下保持较好的生长态势。     

石油污染盐碱土壤翅碱蓬根围的细菌多样性及耐盐石油烃降解菌筛选

为了更好地了解石油污染盐碱土壤翅碱蓬根围的细菌多样性,采用16S rRNA基因克隆文库方法对其进行分析,在此基础上采用富集培养方法从该生境中分离筛选耐盐石油烃降解菌.16S rRNA基因克隆文库分析结果表明,海杆菌属(Marinobacter)、食烷菌属(Alcanivorax)和假单胞菌属(Pseudomonas)是该生境中的优势菌.他们可能在石油污染盐碱土壤翅碱蓬植物修复过程中起重要作用.进一步采用富集培养方法,从该生境中分离得到8株耐盐石油烃降解菌,可以耐受6％-10％浓度的NaCl,石油烃降解率在32.3％-57.0％之间.经16S rRNA基因序列分析,8株菌隶属于戈登氏菌属(Gordonia)、无色杆菌属(Achromobacter)、迪茨菌属(Dietzia)、芽胞杆菌属(Bacillus)和假单胞菌属(Pseudomonas).他们可能参与石油污染盐碱土壤翅碱蓬植物修复过程中的石油烃降解.