盐腺在红树耐盐中作用初探

红树林分布在热带及亚热带海岸潮间带,具有多种抗盐机制以适应高盐环境.本文以采自海南东寨港国家级自然保护区潮间带滩涂的19种红树植物为实验材料,探究盐腺在红树耐盐中的作用.利用微分干涉差显微镜观察其叶片的表皮结构,发现老鼠簕（Acanthus ilicifolius）、美国大红树（Rhizophora mangle）、无瓣海桑（Sonneratia apetala）、海桑（Sonneratia caseolaris）、白骨壤（Avicennia marina）、尖瓣海莲（Bruguiera sexangula var.rhynchopetala）、萌芽白骨壤（Avicennia germinans）、桐花树（Parmentiera cerifera）、阿吉木（Aegialitis annulata）等9种红树叶片表面具有盐腺,而玉蕊（Barringtonia racemosa）、水黄皮（Pongamia pinnata）、卤蕨（Acrostichum aureum）、木果楝（Xylocarpus granatum）、银叶树（Heritiera littoralis）、拉贡木（Laguncularia racemosa）、秋茄树（Kandelia obovata）、木榄（Bruguiera gymnorrhiza）、红茄苳（Rhizophora mucronata）和榄李（Lumnitzera racemosa）等10种红树没有盐腺.通过对相同生境下19种红树成熟叶片表面及内部Na＋含量的测定发现,老鼠簕、无瓣海桑、白骨壤等有盐腺红树叶片Na＋含量及Na＋分泌量均较无盐腺红树高.这些结果表明,具盐腺的红树具有积累盐分的特性,也通过盐腺把过多盐分分泌到体外而适应高盐环境.     

红树植物耐盐–耐淹性的荟萃分析及其应用对策

基于盐度和潮汐淹水对红树植物筛选和定植的重要作用, 选择5种中国造林工程中常用的红树植物, 采用文献检索和荟萃分析方法, 探究其耐盐–耐淹性。结果表明: 白骨壤(Avicennia marina)的耐盐–耐淹性最强 , 能 够 生 长 于 高 盐 度 (40‰)和 长 时 间 淹 水 (16 h/d)环 境 中 ; 秋 茄 (Kandelia obovata)和 桐 花 树 (Aegicerascorniculatum)具 有 较 强 的 耐 盐 –耐 淹 性 , 能 够 生 长 于 中 盐 度 (30‰)和 较 长 时 间 淹 水 (12 h/d)环 境 中 ; 木 榄(Bruguiera gymnorrhiza)和无瓣海桑(Sonneratia apetala)的耐盐性较低, 能够生长于低盐度(20‰)环境中, 前者可种植在较长时间淹水(12 h/d)区域; 超过单一盐度或淹水胁迫耐受限度时, 复合胁迫会降低红树植物的耐受性; 在实际造林应用中, 白骨壤、秋茄和桐花树具有较强的耐盐–耐淹性, 适合中国南部沿海的红树林宜林地。最后, 提出相应的工程应用对策, 可为中国红树林的精准修复提供科学依据。     

北仑河口的红树林及其生态恢复原则

以东兴河桥为起点,1km为单位尺度,将北仑河口岸线划分为12个岸段,其中第12岸段长为2km。在各岸段进行优势群落样方调查。同一群落选3个样方。每样方面积16m^2,用取土器钻取各群落20cm-40cm土层土壤3份,用于测定土壤含水量、全N和全P。广西北仑河口的红树林由7种红树植物和6种群落类型组成。与广西其它海岸相比,老鼠Le和卤蕨群落在该河口发育良好。严重的滩涂侵蚀、红树林生境的破碎和土壤养分的明显缺乏是北仑河口次生红树林自然恢复困难的主要原因。不同的红树植物生长在不同的岸段是对盐度响应的结果。北仑河口123km长的岸线可大体上划分为内河（2km)、河口（5km）、近海河口（2km)、近海（3km)4个生态区间。应用工程的方法提高滩涂的高程,引入红树林新品种是北仑河口红树林生态恢复的关键。     

黄河河口湿地潮汐作用下土壤盐分异质响应研究

对黄河三角洲潮间带与潮上带土壤盐分的空间分布特征分析,结果表明:(1)受海水及较低植被盖度的影响,潮间带地区变异性较低,而潮上带地区具有较强的变异性.垂直方向上,各土层的含盐量极值比以及变化幅度均成明显下降趋势.(2)潮上带,地下水埋深越深表层土壤盐分含量越低,而近海岸以柽柳为优势种的潮间带地区,土壤表层盐分较高而其地下水埋深相对较深.(3)不同群落中土壤盐分剖面分属于表聚型、平均型和底聚型,垂直方向上,随着土壤深度的增加,土壤盐分变异系数逐渐变小.(4)柽柳群落、碱蓬群落与芦苇群落的土壤盐分类型均为氯、钠型;朝间带地区土壤氯、钠离子的含量随不同植被的变化规律为芦苇柽柳碱蓬,反映出碱蓬植物较高的耐碱与吸盐能力.     

Alterations in phosphoproteome under salt stress in Thellungiella roots

High salinity stress is a major environmental factor that limits plant’s distribution and productivity. An Arabidopsis-related halophyte, Thellungiella halophila, is an emerging model system used for plant abiotic stress tolerance research. Previous studies have suggested that protein phosphorylation has a crucial role in the high salinity response in plants. However, the phosphoproteome differential expression under high salinity stress in halophytes has not been well studied. In this report, phosphoproteome differential expression was analyzed under high salinity stress in Thellungiella roots. Twenty-six putative phosphoproteins were found to have changed expression pattern at the post-translational level. Twenty of these were identified by mass spectrometric analysis, including 18 upregulated and two downregulated phosphoproteins. These proteins were involved in a variety of cellular processes, such as signal transduction, ROS detoxification, energy pathway, protein synthesis and protein folding. While most of these salt-responsive putative phosphoproteins are known salt-stress-related proteins, some of them have not been previously reported. Our results provide not only new insights into salt stress responses in Thellungiella but also a good foundation for further investigation of these high salinity-regulated phosphoproteins.     

Genetic mechanisms and evolutionary significance of natural variation in Arabidopsis

Genomic studies of natural variation in model organisms provide a bridge between molecular analyses of gene function and evolutionary investigations of adaptation and natural selection. In the model plant species Arabidopsis thaliana, recent studies of natural variation have led to the identification of genes underlying ecologically important complex traits, and provided new insights about the processes of genome evolution, geographic population structure, and the selective mechanisms shaping complex trait variation in natural populations. These advances illustrate the potential for a new synthesis to elucidate mechanisms for the adaptive evolution of complex traits from nucleotide sequences to real-world environments.     

Photosynthetic recovery of desiccated intertidal seaweeds after rehydration

Intertidalseaweedsusuallyexperiencehoursto daysofdesiccationduringemersionbeforebeingim mersedagainintidecycles[1].Tosomespeciesofsea weedsthedesiccationimposednegativeeffectson photosynthesisandrespiration[2—6],itcouldalsoen hancethenetphotosynthesisofmostdetectedsea weedsattheinitialphaseofthewaterlosingpro cess[5,7—12].However,littlehasbeendocumentedon therelationshipofphotosyntheticrecoverywithwater retainingability.Desiccation resistantperformancesofintertidal seaweedswereconsideredtobe…     

Photosynthetic recovery of desiccated intertidal seaweeds after rehydration

Intertidal seaweeds experience periodical desiccation and rehydration to different extents due to the tidal cycles and their vertical distributions. Their photosynthetic recovery process during the rehydration may show different patterns among the seaweeds from different zonations or depths at intertidal zone. In this study 12 species of seaweeds collected from the upper, middle, lower and sublittoral zones were examined. The relationship of the photosynthetic recovery to vertical distribution was assessed by comparing their patterns of photosynthetic and respiratory performances after rehydration following desiccation. Both the photosynthesis and dark respiration declined during emersion, showing certain degrees of recovery after re-immersion into seawater for most species, but the extents were markedly different from one species to the other. The species from upper intertidal zone after being rehydrated for 1 hour, following 2 hours of desiccation, achieved 100% recovery of their initial physiological activity, while most of the lower or sublittoral species did not achieve full recovery. It is the ability to withstand desiccation stress (fast recovery during rehydration), but not that to avoid desiccation (water retaining ability) that determines the distribution of intertidal seaweeds. Such physiological behavior during rehydration after desiccation reflects the adaptive strategy of intertidal seaweeds against desiccation and their capability of primary production in the process of rehydration.     

天津滨海湿地土壤盐分空间演变规律研究

天津滨海的天然湿地主要起源于全新世中、晚期以来的海陆变迁,后来的海陆交互作用以及人类活动使其产生了不同程度的盐渍化.为研究湿地土壤盐分自潮间带向内陆演进的演变规律,依据距海距离,选取潮间带(0 km)、北大港(24 km)、七里海(38 km)和大黄堡(70 km)4个典型滨海湿地,对其土壤盐分的演变规律进行分析.结果显示:(1)土壤含盐量和电导率自潮间带向内陆呈显著指数递减趋势,并表现出表层(0~5 cm)聚集特征.(2)除(HCO3-+CO32-)外,离子含量与距海距离之间呈极显著指数负相关关系.潮间带、七里海和大黄堡湿地的土壤阳离子均以Na+为主,而北大港湿地以Na+和Ca2+组成占绝对优势.从潮间带到内陆湿地,土壤中阴离子从以Cl-为主过渡到以Cl-、SO42-和HCO3-+CO32-为主.(3)除大黄堡湿地,各湿地含盐量均与Cl-呈极显著正相关,与SO42-从潮间带湿地到内陆湿地由不相关过渡到极显著正相关,HCO3-+CO32-与含盐量仅在北大港湿地呈极显著正相关.(4)潮间带湿地土壤表层(0~5 cm)和中间层(20~50 cm)为弱碱化土,次表层(5~20 cm)和深层(50~100 cm)为中度碱化;北大港和大黄堡湿地整个1 m土层均为弱碱化;七里海湿地为中度碱化.     

海草光合作用研究进展

生活在潮间带和潮下带海水中的单子叶植物海草,在生理生态方面对海洋沉水环境形成了一系列的适应,其光合作用受到光照、温度、无机碳和盐度等环境因子的影响,其中光照和无机碳常常成为限制因子。为了适应低无机碳的海洋环境,海草具有利用HCO-3能力,并在光合代谢上形成一定的适应性。全球气候变化与人类活动可以通过改变光照、温度等环境因子进而影响到海草床的演化。     

影响青少年短跑运动员放松的因素及训练方法研究

运用文献资料法、问卷调查法、实验法及数理统计法等科研方法,以生理学、人体解剖学、心理学及运动生理学、运动心理学、运动生物化学、运动训练学等理论为基础,对影响青少年短跑运动员放松的因素进行了系统和多角度的研究,主要从训练学、心理学和社会学三个方面提出了相应的放松训练的方法.     

白骨壤对关键环境因子的生态响应研究进展

白骨壤（犃狏犻犮犲狀狀犻犪犿犪狉犻狀犪）是红树林生态系统的先锋植物.为适应低温、高盐、淹水、土壤缺氧和潮水冲击等诸多不良因子的影响,白骨壤已特化出一套适应机制：包括形态结构、水分、光合作用、蒸腾作用、气孔导度、生物量和生长等.本文综述了白骨壤对低温、盐度、土壤、潮水浸淹、风浪作用等环境因子的生态响应,指出白骨壤作为先锋树种和乡土树种,对环境具有较强的耐受性和适应性并能有效保护生态安全,可作为红树林造林优先选择的树种,应深入研究其与各环境因子的生态响应机制,为红树林造林地选择及生态修复提供科学依据.     

盐胁迫下植物质膜H+-ATPase研究进展

质膜H -ATPase在植物细胞的跨膜物质转运、胞内pH值调节以及植物对环境胁迫的响应等诸多方面具有重要作用,是植物生命活动过程的主宰酶.盐胁迫是影响植物生长发育的主要环境因子,植物质膜H -ATPase活性的调节是植物适应盐环境、提高耐盐性的重要细胞机理.综述了植物质膜H -ATPase活性变化及其调节机理对盐胁迫响应的研究状况,对质膜H -ATPase活性调节机理研究中仍未解决的问题进行了展望.     

Insect population differentiation in response to enviromental thermal stress

Numerous studies reported the adaptation strategies adopted by ecthotherms to survive under environmental thermal stress. Geographic and seasonal variations in the thermal stress tolerance, which is closely associated with species' climatic adaptation and allopatric speciation, have been extensively investigated in insects. The variation patterns suggest directional selection for species' adaptive straits, and are used to predict the origin, distribution and dynamics of insect populations. These studies are becoming more and more important in the context of global warming. This paper discusses the process of adaptation to environmental thermal stress and the mechanisms underlying the differentiation in related adaptive straits of insect populations.     

Insect population differentiation in response to enviromental thermal stress

Innature,somespeciesoccupyarestrictedgeo graphicrangewhilesomeothershaveawideorevencosmopolitandistribution .Somespeciesonlyemergeinmildseasonswhilesomeothershavedominatingpopulationsoverseasons .Thus,thepopulationdy namicsofspeciesvariesindifferenttemporalandspa tialniches,reflectingdifferentrequirementsforther malbudgetandhabitattraits[1— 3].Generally ,species’abilitytosurvivethermalstress ,togetherwithotherfactors,hasdetermineditsrangeandpo tentialregionaldistribution[4 ].Inthepastdecades…     

野大豆与栽培大豆愈伤组织耐盐性比较

野大豆(Glycine soja)是唯一能与栽培大豆(Glycine max)杂交而后代能育的野生近缘种,具有极强的耐盐碱性,利用野大豆与栽培大豆有性杂交,结合离体组织培养技术,进行耐盐性变异体的离体筛选,是提高大豆耐盐性的一种有效途径。本研究选择5种栽培大豆品种和从黄河三角洲地区(山东东营)获得的野大豆,进行了大豆成熟胚愈伤组织诱导及愈伤组织耐盐性研究。结果显示,不同浓度Na Cl胁迫下,野大豆愈伤组织的存活率明显高于栽培大豆,与对照相比鲜重下降幅度明显低于栽培大豆;Na Cl胁迫下,野大豆愈伤组织的超氧化物歧化酶(SOD)和过氧化物酶(POD)活性明显高于栽培大豆愈伤组织,MDA含量明显低于栽培大豆,表明野大豆愈伤组织耐盐性明显优于栽培大豆。该研究为耐盐大豆新品种培育提供了理论依据。     

盐性条件下的AM真菌以及AM真菌提高植物耐盐性研究

本文针对国内外有关盐性条件下的丛枝菌根相关报道,概述了自然盐性土壤中的AM真菌,盐胁迫对丛枝菌根的影响作用以及盐胁迫下AM菌根对植物的影响。许多研究表明,在自然盐性土壤中存在着大量的AM真菌,土壤盐度影响着菌根的形成和发育;在盐性环境下,AM真菌能促进植物的生长和对矿质营养的获取,提高植物的耐盐性。因此,菌根对盐碱土壤中植物的生长有着潜在的促进作用,植物菌根修复技术将助于盐碱土壤的开发、改良。     

耐盐木霉ST02对番茄种子和幼苗盐耐受能力的影响

木霉菌能够促进植物对盐胁迫的耐受性,研究选用耐盐木霉选择培养基筛选获得的木霉菌株ST02,对其耐盐活性进行检测,具有较强耐盐活性.用ST02木霉菌株的孢子悬液对番茄种子和幼苗进行处理,分析木霉处理对盐胁迫条件下番茄种子萌发,幼苗生长和耐盐生理生化的影响.结果显示:ST02孢子悬液促进NaCl胁迫下番茄种子的发芽率和发芽势,提高200 mmol/L NaCl胁迫下番茄幼苗的存活率、株高和鲜重,以及番茄幼苗的叶绿素含量和净光合速率,影响番茄幼苗的离子渗漏率和丙二醛(malondialdehyde,MDA)含量,提高超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)等抗氧化酶的活性.说明木霉ST02孢子悬液处理能够通过提高植物的抗氧化防御反应促进番茄对NaCl胁迫的耐受性.     

植物耐盐性研究进展

对近年来植物在盐环境下所受的伤害和植物的耐盐机理的相关研究作一综述,以期为深入揭示植物耐盐机理,筛选耐盐植物新品种提供参考依据.     

微波处理对不同植物种子活力及耐盐性的影响

为了研究微波预处理工艺对不同种类植物种子耐盐性的影响及所选工艺参数的普遍性，用NaCl溶液和原生水分别作种子萌发的培养液，选择蔬菜种子（白菜）、草本植物（高羊茅、黑麦草）和木本植物（刺槐）为实验对象，以相对幼苗活力指数评价种子的耐盐性，采用对比实验考察了微波预处理对4种不同种类植物种子活力的影响．结果表明，NaCl单一盐类对种子萌发的胁迫作用均比原生水复合盐类大；对2g种子，在原生水培养条件下，微波参数2450MHz、65W，辐照6s，间隔10min，重复照射1次，处理后种子的相对幼苗活力指数均显著提高，增幅为31％～84％．虽然上述种子种类不同，但由于微波因素影响种子活力的生理生化基础及其作用机制相同，所以同样的微波处理工艺参数均能达到显著提高种子活力的效果。