小麦耐盐细胞系对盐胁迫的伤害性反应

通过逐级提高ＮａＣｌ浓度的筛选方法,得到了能在１．５％ＮａＣｌ下生长良好的小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．）耐盐细胞系。在盐分胁迫下,耐盐细胞系含水量的降低幅度小于不耐盐细胞系（对照）,Ｈ２Ｏ２含量和Ｏ－２产生速率的增加幅度也明显小于对照细胞系。同时,膜的相对透性、膜脂过氧化和脱酯化程度的提高幅度也明显低于对照细胞系。表明盐分对小麦细胞系膜的伤害与活性氧介导的膜脂过氧化和脱酯化有关,而耐盐细胞系比对照细胞系表现出较强的抗活性氧伤害的能力。     

植物盐胁迫应答的分子机制

植物对盐胁迫的耐受反应是个复杂的过程,在分子水平上它包括对外界盐信号的感应和传递,特异转基录因子的激活和下游控制生理生化应答的效应基因的表达。在生化应答中,本着重讨论负责维持和重建离子平衡的膜转运蛋白、渗调剂的生物合成和功能及水分控制。这些生理生化应答最终使得液泡中离子浓度升高和渗调剂在胞质中积累,近年来,通过对各种盐生植物或盐敏感突变株的研究,阐明了许多盐应答的离子转运途径、水通道和特种特异的渗调剂代谢途径,克隆了其相关基因并能在转基因淡水植物中产生耐盐表型,另一方面,在拟南芥突变体及利用酵母盐敏感突变株功能互补筛选得到一些编码信号传递蛋白的基因,这些都有助于阐明植物盐胁迫应答的分子机制。     

3种野生地被植物对践踏胁迫的生理生态响应特征

不同强度践踏胁迫下,对3种野生地被植物主要生理生态响应特征进行了研究,结果表明：重度践踏胁迫下匍枝委陵菜的盖度、生物量下降幅度最大,和对照相比分别下降46.58%和43.53%。重度践踏胁迫下车前的纤维素含量最高,比对照增加43.31%。中度践踏胁迫下紫花地丁丙二醛含量积累最少,比对照升高28.57%。紫花地丁叶绿素含量对践踏胁迫响应敏感,轻度践踏可使叶绿素含量提高45.21%（p< 0.05）,重度践踏使匍枝委陵菜和紫花地丁的叶绿素含量分别下降了21.59%和29.37%。践踏胁迫使3种野生地被植物的群体净光合速率下降。综合分析结果为车前最耐践踏,紫花地丁次之,匍枝委陵菜最不耐践踏。     

罗布麻对不同浓度盐胁迫的生理响应

利用网室盆栽实验, 研究不同浓度的NaCl(100–400 mmol·L^–1)胁迫对罗布麻(Apocynum venetum)生长及生理特性 的影响。结果表明, 100 mmol·L^–1NaCl处理显著降低了罗布麻植株的鲜重, 但对其干重影响不大; 随着盐浓度继续增加, 罗布麻鲜重和干重显著下降。在盐胁迫下, 罗布麻叶片内的丙二醛含量、电解质渗漏率、根部和地上部Na⁺的含量明显增加, K⁺的含量随着盐离子浓度的增加而降低。盐胁迫显著降低了地上部Ca²⁺的含量, 而对根部Ca²⁺的含量没有影响。植株K⁺/Na⁺和Ca²⁺/Na⁺比值随着盐胁迫强度的增加而降低。盐胁迫显著促进了罗布麻根部对K⁺和Ca²⁺的选择性吸收及对K⁺的选择性运输。当NaCl浓度小于或等于200 mmol·L^–1时, 随着盐离子浓度的增加, 罗布麻叶片内的脯氨酸和可溶性糖积累显著增加,而当NaCl浓度大于200 mmol·L^–1时, 这2种有机溶质含量显著下降。总体上, 罗布麻通过积累无机离子、合成有机溶质及维持较高的K⁺、Ca²⁺选择性吸收和运输来适应一定浓度(≤200 mmol·L^–1NaCl)的盐胁迫。     

Linkage Relationships in Wild Emmer Wheat, TRITICUM DICOCCOIDES

The linkage relationships in wild emmer wheat, Triticum dicoccoides , between nine enzymatic loci (Mdh-1, Ipo, β-Glu, Pept-1, Pept-3, Est-5, Est-1, 6Pgdh-2 and Hk) and a coleoptile pigment locus (Rc) were investigated. Chromosome locations of genes were inferred from analysis of ditelocentric lines of Triticum aestivum, cultivar Chinese Spring. The loci Mdh-B1 and Hk are linked (lambda = 0.1869) and are most likely located on the chromosome 1B. The loci Pept-B1 and Rc are linked (lambda = 0.2758) and are located on the 6Bq chromosomal arm. Rc also has significant interactions with the loci Pept-3 and Ipo, although there is no significant linkage detectable. The interactions may be a result of epigenetic interactions. Est-1 has only one active product in T. dicoccoides and is most likely located on the 3Ap chromosome arm. No significant interactions were found for the remaining loci.     

罗布红麻胚性愈伤组织诱导及其对盐胁迫的生理反应

目的:探寻获得罗布红麻胚性愈伤组织的最佳培养基和条件,并探讨该愈伤组织对盐胁迫的生理反应.方法:设计不同激素配比和浓度培养基,诱导并挑选、扩增胚性愈伤组织.对罗布红麻胚性愈伤组织进行不同浓度的盐胁迫(0、50、70、100和200numl/L),研究其在不同时期不同浓度盐胁迫下的脯氨酸含量、丙二醛含量、超氧化化物歧化酶(SOD)的活性变化、及超氧化物歧化酶同工酶和过氧化物同工酶的谱带变化.结果:获得了大量罗布红麻胚性愈伤组织及其盐胁迫下的生理生化数据和图谱.结论:罗布红麻胚性愈伤组织的产生主要依赖0.5mg/L2,4-D的作用,此外,转瓶过程中细心观察,不断挑选也很重要.不同浓度的盐胁迫不同时问,从MDA和脯氨酸含量变化上看,经50～70mmol/L.盐胁迫3～5d,罗布红麻胚性愈伤组织进入最敏感期,之后它对盐胁迫有个快速适应过程;根据SOD酶活性变化,盐胁迫第7d时,经70mmoL/L以上的NaCl处理组SOD酶活均保持在一个较高的水平,说明此时SOD酶正在发挥重要作用;从SOD同工酶谱看,Rf值为0.46的酶带是盐胁迫组特有的,说明它与盐胁迫密切相关;从POD同工酶谱看,Rf值为0.01的条带为J0、J2、J5组特有,带很窄但色较深,此酶带所代表的酶对盐的敏感性存在特殊性.     

Proteome Dynamics and Physiological Responses to Short-Term Salt Stress in Brassica napus Leaves

Salt stress limits plant growth and crop productivity and is an increasing threat to agriculture worldwide. In this study, proteomic and physiological responses of Brassica napus leaves under salt stress were investigated. Seedlings under salt treatment showed growth inhibition and photosynthesis reduction. A comparative proteomic analysis of seedling leaves exposed to 200 mM NaCl for 24 h, 48 h and 72 h was conducted. Forty-four protein spots were differentially accumulated upon NaCl treatment and 42 of them were identified, including several novel salt-responsive proteins. To determine the functional roles of these proteins in salt adaptation, their dynamic changes in abundance were analyzed. The results suggested that the up-accumulated proteins, which were associated with protein metabolism, damage repair and defense response, might contribute to the alleviation of the deleterious effect of salt stress on chlorophyll biosynthesis, photosynthesis, energy synthesis and respiration in Brassica napus leaves. This study will lead to a better understanding of the molecular basis of salt stress adaptation in Brassica napus and provides a basis for genetic engineering of plants with improved salt tolerance in the future.     

盐胁迫下盐桦生理响应的变化分析

对组织培养获得的盐桦（Belula halophila）苗在盐胁迫下的生理指标和解剖结构进行了分析,结果显示,随着盐浓度的增加,植物叶片相对含水量逐渐降低;脯氨酸（Pro）含量逐渐增加;叶片丙二醛（MDA）含量和过氧化氢酶（CAT）活性大小存在相关性,在50～200mmol／L盐胁迫下,植物的CAT活性是递增的,200mmol／LNaCl处理时达到最高,同时叶片MDA含量在50～200mmol／L盐处理时变化不明显;CAT活性在300mmol／LNaCl处理时突然降低,此时叶片MDA含量大;植物叶片和根的离子含量测定表明,在盐胁迫下K^＋／Na^＋比值逐渐降低,叶片中K^＋含量始终高于Na^＋含量;石蜡切片和扫描电镜发现盐桦茎、叶中有晶体状物质存在,通过X-ray分析表明这种晶体含有C,O,Ca元素,相关的细胞成分化学实验进一步确定其结晶体的成分。     

罗布麻对不同浓度盐胁迫的生理响应

利用网室盆栽实验,研究不同浓度的NaCl（100-400mmol·L^-1）胁迫对罗布麻（Apocynum venetum）生长及生理特性的影响。结果表明,100mmol·L^-1NaCl处理显著降低了罗布麻植株的鲜重,但对其干重影响不大;随着盐浓度继续增加,罗布麻鲜重和干重显著下降。在盐胁迫下,罗布麻叶片内的丙二醛含量、电解质渗漏率、根部和地上部Na^＋的含量明显增加,K^＋的含量随着盐离子浓度的增加而降低。盐胁迫显著降低了地上部Ca^2＋的含量,而对根部Ca^2＋的含量没有影响。植株K^＋/Na^＋和Ca^2＋/Na^＋比值随着盐胁迫强度的增加而降低。盐胁迫显著促进了罗布麻根部对K^＋和Ca^2＋的选择性吸收及对K^＋的选择性运输。当NaCl浓度小于或等于200mmol·L^-1时,随着盐离子浓度的增加,罗布麻叶片内的脯氨酸和可溶性糖积累显著增加,而当NaCl浓度大于200mmol·L^-1时,这2种有机溶质含量显著下降。总体上,罗布麻通过积累无机离子、合成有机溶质及维持较高的K^＋、Ca^2＋选择性吸收和运输来适应一定浓度（≤200mmol·L^-1NaCl）的盐胁迫。     

四翅滨藜生理生化特征对盐胁迫的响应

采用温室盆栽试验研究四翅滨藜(Atriplex canescens)幼苗株高、地径、生物量、净光合速率、蒸腾速率、气孔导度、叶绿素含量、抗氧化酶活性及丙二醛含量对不同浓度NaCl和Na_2SO_4(0、100、200、300和400mmol·L~(-1))胁迫的响应,以探讨四翅滨藜对不同种类及不同浓度盐渍环境的适应机制及其耐盐机理。结果显示:(1)随着盐分浓度的升高,四翅滨藜幼苗的株高、地径及生物量增量呈现出先升高后降低的趋势,低盐浓度下2种盐均促进幼苗生长,盐浓度超过400mmol·L~(-1)时,NaCl对幼苗生长具有明显抑制作用。(2)2种盐处理下,四翅滨藜幼苗净光合速率(Pn)和叶绿素含量(Chl)随盐浓度增大而升高,即2种盐均对幼苗Pn和Chl含量具有促进作用,且Na_2SO_4的促进效果大于NaCl;而幼苗蒸腾速率(Tr)和气孔导度(Gs)随盐浓度升高呈先增大后减小的趋势,且Na_2SO_4的促进作用强于NaCl。(3)与对照相比,四翅滨藜幼苗的丙二醛、SOD、POD酶活性在NaCl和Na_2SO_42种盐处理下,随着盐浓度的升高均呈现出不同程度的增大,且增大幅度总体表现为NaClNa_2SO_4。研究表明,四翅滨藜在NaCl和Na_2SO_4胁迫下,叶绿素的分解速率以及发挥作用的渗透调节物质均有差异,使得幼苗叶片健康程度不同,导致叶片光合能力大小的差异,最终表现为植株的生长差异;四翅滨藜具有较强的耐盐能力,而且对Na_2SO_4的适应能力强于NaCl。     

Physiological,Biochemical and Molecular Responses of Barley Seedlings to Aluminum Stress

Barley (Hordeum vulgare L.) is one of the most Aluminum (Al) sensitive cereal species. In this study, the physiological, biochemical, and molecular response of barley seedlings to Al treatment was examined to gain insight into Al response and tolerance mechanisms. The results showed that superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activity were inhibited to different degrees following Al exposure. The MDA content also significantly increased with increasing Al concentrations. SRAP results indicated significant differences between Al treatments and controls in terms of SRAP profile, and the genomic template stability (GTS) decreased with increasing Al concentration and duration. These integrative results help to elucidate the underlying mechanisms that the barley response to Al toxicity.     

三角梅对盐胁迫的响应研究

长期盐胁迫处理实验表明,随着NaCl浓度增加,不同三角梅品种的地上部和地下部生物量均呈下降趋势。与对照相比,盐浓度为5%时,勤花三角梅生物量下降幅度最小,为27.94%;樱花三角梅下降最大,为67.03%。当盐浓度为4%时,樱花三角梅、白苞三角梅和勤花三角梅的光量子产量分别为0.36、0.30和0.36,分别为对照的78.23%、79.64%和74.82%;金心鸳鸯三角梅的光量子产量为0.05,仅为对照的15.53%。白苞三角梅的光化学猝灭系数qP值随着盐浓度的升高无明显变化;金心鸳鸯三角梅、勤花三角梅和樱花三角梅的qP值随着盐浓度的升高而降低。4个三角梅品种的抗盐胁迫能力为：白苞三角梅>樱花三角梅>勤花三角梅>金心鸳鸯三角梅。     

盐胁迫下藜的形态结构与生理响应

本文采用石蜡切片、扫描电镜和体视显微镜对藜进行了形态结构观察和多种生理指标检测,研究在盐胁迫下藜的结构和生理变化。结果表明：在花期,藜的株高和茎粗显著降低,叶未产生明显肉质化。高盐（300mmol·L^-1）胁迫下,叶维管束的导管数量及形成层层数增加,茎的维管束密度增加,根木质化程度增强,大导管密度显著降低。叶下表面的盐囊泡较上表面多,叶和茎细胞中均含有簇状结晶。随着盐浓度的升高,叶片中含水量降低,相对电导率升高,丙二醛（MDA）含量无显著变化,叶绿素含量在苗后期先升高后降低,在花期,其含量随盐浓度升高而降低。300mmol·L^-1盐胁迫下,苗后期的可溶性糖、脯氨酸7L-N-菜碱含量显著增J／w;至花期,脯氨酸及甜菜碱含量显著高于对照。以上结果初步显示,高浓度盐胁迫对花期的藜形态结构及部分生理指标均比苗期产生显著影响,但300mmol·L^-1盐胁迫下藜仍能完成其生活史。     

抗旱性不同的冬小麦幼苗对渗透胁迫的生理效应

抗旱性不同的冬小麦幼苗在渗进胁迫下叶片相对透性、Pro含量和在总游离氨基酸中的Pro比例均增加,但品种间变化幅度有明显差别。在严重胁迫下,抗旱性弱的品种济南13,烟农15和鲁麦5号的叶片相对透性增加大于抗旱性强的品种昌乐5号,秦麦3号和山农587;而Pro含量和在总游离氨基酸中Pro比例的增加小于抗旱性强的品种、叶片Pro累积与RWC呈显著负相关。     

Physiological Characteristics and Alternative Respiratory Pathway under Salt Stress in Two Wheat Cultivars Differing in Salt Tolerance

Changes in respiratory pathway, dry weight, contents of proline, ATP, Na⁺and K⁺were investigated under five salinity treatments in the leaves of plants of spring wheat (Triticum aestivumL.). Two cultivars differing in salt resistance, namely, 89122 (salt-tolerant) and Longchun13 (salt-sensitive), were used. The decrease in dry weight and K⁺content was observed with the increasing NaCl concentrations, but more in cv. 89122 plants than in Longchun13 plants. Contents of proline and Na⁺in both cvs increased greatly, but the former increased more in 89122 while the latter more in Longchun13 plants. In all salinity treatments tested, a salt-induced increase in the activity of the alternative pathway was found, although cytochrome pathway (CP) still remained the main electron transport pathway. ATP production changed in parallel with CP operation. Cv. 89122 plants could produce more ATP than cv. Longchun13 plants exposed to each salinity treatment and their ATP generation could even be stimulated in contrast to its rapidly decline in Longchun13 plants with increased salinity stress. The possible relationship between respiration metabolism and above mentioned physiological changes is discussed.     

Distinct Cellular and Organismic Responses to Salt Stress

We have compared metabolic effects of high salinity betweenplants and cell suspension cultures from the facultative halophyteMesembryanthemum crystallinum (common ice plant). This plantshows developmentally-programmed inducibility for a switch fromC₃-photosynthesis to CAM (Crassulacean Acid Metabolism). Themetabolic switch is enhanced by environmental factors such asdrought, low temperature, and, most effectively, soil salinity.CAM induction is dependent on organized leaf tissue and cannotbe elicited by salt stress in suspension culture cells. In contrast,the accumulation of proline [Thomas et al. (1992) Plant Physiol.98: 626] is induced by NaCl in cultured cells as well as inplants and must be considered a cellular response to stress.We have extended our observations to include another trait ofsalt- and low-temperature-stress responses in the ice plant,the accumulation of putative osmoprotective sugars and sugaralcohols. In whole plants the cyclic sugar alcohol, pinitol,accumulates to amounts that approach 1 M during stress, whilein suspension cells no increase in sugar alcohols is observed.The distribution of carbon to different sugars is markedly differentbetween cells and plants under stress. Particularly obviousis the distinction between cell types in the different compositionof sugars and polyols, as exemplified by the epidermal bladdercells of ice plants. Ion contents and the content of sugarsand sugar alcohols of bladder cells indicate that Na⁺, Cl^–,pinitol and an unknown carbohydrate compound provide osmoticpressure in these cells, while organic anion concentrationsare low. With the ice plant, we conclude that cells in culturemimic only partly the stress response mechanisms of intact plantsand we hypothesize that communication between different tissuesis required to mount a complete environmental stress response. ⁴ Present address: Department of Botany Oklahoma State University,Stillwater, OK, 74078, U.S.A.     

Responses of Seidlitzia rosmarinus to Salt Stress

The responses of the salt-accumulating halophyte Seidlitzia rosmarinus to salt stress (500 mM NaCI) were studied. Observations were carried out over the span of 72 h. Three phases of responses were identified. Parallel observations of physiological parameters and cell ultrastructure allowed us to conclude that S. rosmarinus is capable of resisting salt stress owing to changes in its osmoregulatory systems (ions or organic osmolytes). In addition, these observations showed that salt ions are localized in the central vacuole of leaf cells (via pinocytosis) and also in small cytoplasmic vacuoles of leaf and root cells.