不同盐浓度的混合盐对羊草苗的胁迫效应

用５０～３５０ｍｍｏｌ／Ｌ含有不同比例的ＮａＣｌ、Ｎａ２ＳＯ４、ＮａＨＣＯ３和Ｎａ２ＣＯ３等４种盐成分的３０种混合盐对羊草（Ａｎｅｕｒｏｌｅｐｉｄｉｕｍｃｈｉｎｅｎｓｅ（Ｔｒｉｎ．）Ｋｉｔａｇ．）苗进行盐碱混合胁迫处理。结果表明：相对生长率、Ｋ和Ｎａ含量、脯氨酸积累量及叶片电解质外渗率等胁变反应均随盐浓度增大以及碱性盐比例增高而加剧。而且碱性盐所造成的高ｐＨ的致胁变效应与盐浓度关系极大,浓度低时作用较小,随浓度增大其作用加剧。在含有碱性盐的混合盐胁迫中,包含有盐胁迫和碱胁迫两种作用。以总盐浓度代表盐胁强,缓冲量代表碱胁强。在碱胁强较弱时胁变主要受盐浓度影响,随碱胁强增大缓冲量变为影响胁变的主导因素     

盐碱混合生态条件的人工模拟及其对羊草胁迫作用因素分析

将中性盐NaCl和Na2SO4,碱性盐NaHCO3和Ｎa2CO3按不同比例混合,模拟出３０种盐度和pH各不相同的盐碱生态条件,并对羊草苗进行盐碱混合胁迫处理,测定其日相对生长率（ＲＧＲ）等７项胁变指标,用数学方法分析盐度,缓冲量等各种胁迫因素与诸项胁变指标间的相互关系,结果表明：30种处理均匀覆盖了总盐度50-350mmol/L,pH7.14-10.81范围内的各种盐碱条件,用盐度,缓冲量,pH和[Cl^-]即可代表盐碱混合胁迫的所有胁迫作用因素,诸胁变指标与这4因素间均具有高度线性相关性,4因素对胁变的贡献明显不同,其中缓冲量和盐度是决定性的主导因素,pH和[Cl^-]的作用明显次之,有时甚至可以忽略,不同胁变指标与各因素的关系也有不同。分析结果表明,对于盐碱混合胁迫来说,以盐度加缓冲量代表总胁强较为合理。     

盐（NaCl）与碱（Na2CO3）对星星草胁迫作用的差异

对生长在蛭石中8周龄的星星草(Puccinellia tenuiflora(Criseb.)Scribn.et Merr.)用 12.5—800mmol/L 的中性盐 NaCl或碱性盐 Na_2CO_3进行胁迫处理,测定植物日相对生长率等胁变指标。结果表明星星草的抗盐性高于抗碱性,可耐受的最高浓度分别为:中性盐NaCl 600 mmol/L、碱性盐 Na_2CO_3 200mmol/L_o NaCl胁迫下,随胁强增高,脯氨酸明显积累,柠檬酸含量则逐渐下降;Na_2CO_3胁迫下,脯氨酸仅稍有积累而柠檬酸含量却急剧升高。两种胁迫下都表现出:随胁强增大,Na~ 含量明显上升,K~ 含量下降。但是,NaCl胁迫对K~ 含量影响不大,而Na_2CO_3胁迫则导致根及茎叶中的K~ 含量明显下降。诸胁变指标中唯有叶片电解质外渗率对两种胁迫来说变化特点相似。     

盐生植物碱地肤对盐碱胁迫的生理响应特点

以天然盐生植物碱地肤(Kochia sieversiana)为材料,采用人工生态模拟方法对其施加0~480mmol/L的盐胁迫(摩尔比1∶1的NaCl和Na2SO4)和碱胁迫(摩尔比1∶1的NaHCO3和Na2CO3),测定了盐碱胁迫下的相对生长率(RGR)、叶绿素含量及丙二醛含量.结果表明:低浓度的盐胁迫(80mmol/L)对碱地肤的生长具有刺激作用,其在高达480mmol/L的盐胁迫或400mmol/L的碱胁迫下仍能存活并维持一定的生长,具有强抗盐性和强抗碱性;在相同盐浓度下,碱地肤受碱胁迫的伤害强度和对碱胁迫所做出的胁变反应均大于对盐胁迫.可见,碱地肤的抗盐性强于抗碱性,受碱胁迫的伤害大于盐胁迫,维持高含水量可能是碱地肤适应高强度盐碱胁迫的重要特性.     

Na2SO4和Na2CO3胁迫下苦楝幼苗的形态及光合生理特性

为探索苦楝应对盐胁迫的响应机制,该文以1年生苦楝(Melia azedarach)实生苗为材料,在盆栽条件下设置中性盐Na_2SO_4和碱性盐Na_2CO_33个盐浓度(200、400、600 mmol·L~(-1))处理40 d,研究苦楝的抗盐碱水平及在不同程度盐碱胁迫条件下的生长及光合生理变化。结果表明:随着盐浓度的提高,苦楝的苗高、地径和生物量的增长量均呈现下降趋势,且碱性盐胁迫条件下降程度更大,盐胁迫提高苦楝的根冠比。处理10 d时,苦楝幼苗的所有光合指标随中性盐和碱性盐浓度的提高呈相似的下降特征,碱性盐胁迫条件下的降低幅度显著大于中性盐胁迫,且随处理时间的增加,中性盐和碱性盐处理下苦楝幼苗的净光合速率和蒸腾速率显著降低。随着盐浓度的提高,苦楝的叶绿素含量呈现下降趋势,200 mmol·L~(-1)盐胁迫对叶绿素含量影响较小,400、600 mmol·L~(-1)盐胁迫均对叶绿素含量有显著影响。600 mmol·L~(-1)碱性盐胁迫条件下,苦楝叶片相对电导率和饱和水分亏缺最高,显著高于其余处理。同等浓度下,碱性盐胁迫的苦楝叶片相对电导率和饱和水分亏缺显著高于中性盐胁迫处理。综上结果认为,苦楝具有一定的耐盐碱能力,碱性盐比中性盐对苦楝幼苗的影响更大。     

松嫩平原碱化草甸朝鲜碱茅、獐茅耐盐碱特性的比较研究

 本研究通过野外调查与室内实验相结合的方法,从生态学、生理学方面探讨了松嫩平原碱化草甸朝鲜碱茅和獐毛耐盐碱的特性,结果表明：两种植物均生长在含盐、潮湿而贫瘠的土壤上,朝鲜碱茅分布地段的土壤多含碱性盐(Na2CO3)。而獐毛所在地的土壤则多含中性盐(NaCl),这些体现出它们对盐碱适应性的差异。不同浓度的NaCl、Na2CO3胁迫对这两种植物的细胞膜透性、游离脯氨酸含量有明显影响。均以logistic曲线y=k/(1+ea-bx)或直线方程：y=a+bx形式较好地表达出来。说明朝鲜碱茅对NaCl的胁迫敏感,獐毛则对Na2CO3的胁迫敏感。两种植物在自然条件下的生态适应与实验条件下的生理适应相近。     

植物对盐碱胁迫的响应机制研究进展

盐碱胁迫是制约植物生长发育的主要非生物胁迫之一,也是制约农作物生产和生态环境建设的严峻问题。研究作物的耐盐碱机理,对开发和有效利用盐碱地有重要的现实意义。许多研究将盐碱胁迫笼统称为盐胁迫,实际上这是两种不同的非生物胁迫,且碱胁迫对植物的伤害要大于盐胁迫。总结性阐述了盐碱胁迫对植物的危害。从生物量、光合作用、离子平衡和膜透性等方面分析了植物对盐碱胁迫的响应机制,并结合最新研究从多角度综述了植物的抗盐碱机理,包括合成渗透调节物质、提高抗氧化酶活性、对离子的选择性吸收及p H平衡和诱导抗盐碱相关基因表达。提出了抗盐碱性的途径,即外源物质的加入、与真菌的协同效应、利用生物技术手段、培育耐盐碱品种和抗性锻炼。最后针对植物适应盐碱逆境方面的研究进行了展望,提出了当前研究需要解决的问题和突破口,旨在为提高植物耐盐碱能力、增加作物产量提供一定的理论依据。     

盐碱胁迫对赤霞珠葡萄幼苗生长及相关生理指标的影响

【目的】了解不同盐分配比和不同浓度梯度复合盐碱胁迫对‘赤霞珠’葡萄（Vitis vinfera ‘Cabernet Sauvignon’）幼苗生长和抗逆生理指标的影响，确认其耐盐碱性范围及其耐盐碱能力。【方法】 以1年生‘赤霞珠’自根苗为试材，用NaCl、Na2SO4、NaHCO3、Na2CO3按不同比例混合配置中性盐、弱碱性盐、强碱性盐3组复合盐溶液，每组各设置50、100、150 mmol/L3个浓度梯度，以不做处理的溶液作为对照，于幼苗生长期间进行定期浇灌处理，通过室内盆栽试验来模拟不同类型、不同程度盐碱胁迫，在处理后不同时期测定幼苗生长形态、生理及光合指标。【结果】（1）茎粗和叶面积随盐胁迫浓度增大，呈现先增大后减小的趋势， 而‘赤霞珠’幼苗的株高基本呈现下降趋势。其中，中性、弱碱性、强碱性盐胁迫组间相比，‘赤霞珠’幼苗株高在强碱性盐胁迫组150 mmol/L处理10 d、150 mmol/L处理40 d都较同期中性、弱碱性组相应浓度显著降低；（2）随着盐浓度的增大，SOD活性及MDA含量呈先增大后减小的趋势，而‘赤霞珠’幼苗叶片的POD活性呈现缓慢增加的趋势，强碱性盐胁迫组叶片POD活性在处理30-50d时均高于相同浓度的中性、弱碱性盐胁迫处理组，但随着时间处理延长，到处理60 d后逐渐低于同浓度其他两处理组，其中150 mmol/L浓度表现得更明显。；（3）‘赤霞珠’葡萄幼苗胞间CO2浓度、净光合速率、蒸腾速率随着盐碱浓度的增加主要呈下降趋势，其胞间CO2浓度与净光合速率均为50 mmol/L浓度处理时较高。在同期相同盐浓度处理下，叶片净光合速率在强碱性盐胁迫150 mmol/L浓度处理75 d时显著低于同期中性、弱碱性处理组。（4）在相同浓度条件下，强碱性盐胁迫处理的幼苗株高及最大叶面积都显著低于中性盐和弱碱性盐处理组；叶片SOD活性在50 mmol/L中性盐胁迫处理下较CK显著提高了27%；叶片MDA含量在150 mmol/L强碱性盐胁迫下随着时间延长显著逐渐增加。【结论】‘赤霞珠’幼苗生长在盐碱胁迫下受到一定限制，但其株高、叶面积、胞间CO2浓度、净光合速率、蒸腾速率在50 mmol/L浓度处理下均呈现较好的增长趋势，而其株高及茎粗在强碱性盐胁迫150 mmol/L盐碱溶液处理下均增长最不明显；在一定低浓度浓度范围内50 mmol/L盐碱处理有利于赤霞珠葡萄幼苗生长。     

松嫩平原碱化草甸朝鲜碱茅、猿毛耐盐碱特性的比较研究

本研究通过野外调查与室内实验相结合的方法,从生态学、生理学方面探讨了松嫩平原碱化草甸朝鲜碱茅和獐毛耐盐碱的特性。结果表明：两种植物均生长在含盐、潮湿而贫瘠的土壤上,朝鲜碱茅分布地段的土壤多含碱性盐（Ｎａ２ＣＯ３）,而獐毛所在地的土壤则多含中性盐（ＮａＣｌ）．这些体现出它们对盐碱适应性的差异．不同浓度的ＮａＣｌ、Ｎａ２ＣＯ３胁迫对这两种植物的细胞膜透性、游离脯氨酸含量有明显影响,均以ｌｏｇｉｓｔｉｃ曲线ｙ＝ｋ／（１＋ｅ（ａ－ｂｘ））或直线方程：ｙ＝ａ＋ｂｘ形式较好地表达出来。说叫朝鲜碱茅对ＮａＣｌ的胁迫敏感,獐毛则对Ｎａ２ＣＯ３的胁迫敏感。两种植物在自然条件下的生态适应与实验条件下的生理适应相近。     

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.     

Comparison of the effects of salt-stress and alkali-stress on photosynthesis and energy storage of an alkali-resistant halophyte <Emphasis Type="Italic">Chloris virgata</Emphasis>

Seedlings of Chloris virgata were treated with varying (0–160 mM) salt-stress (SS; 1: 1 molar ratio of NaCl to Na₂SO₄) or alkali-stress (AS; 1: 1 molar ratio of NaHCO₃ to Na₂CO₃). To compare these effects, relative growth rates (RGR), stored energy, photosynthetic pigment contents, net photosynthetic rates, stomatal conductance, and transpiration rates were determined. Both stresses did not change significantly the photosynthetic parameters of C. virgata under moderate stress (below 120 mM). Photosynthetic ability decreased significantly only at high stress (160 mM). Thus C. virgata, a natural alkali-resistant halophyte, adapts better to both kinds of stress. The inhibition effects of AS on RGR and energy storage of C. virgata were significantly greater than that of SS of the same intensity. The energy consumption of C. virgata was considerably greater while resisting AS than while resisting SS.     

盐渍化胁迫下油葵对土壤原油污染的适应性及其改良措施

为了探究植物在盐渍化胁迫下对原油污染的适应性及改良措施,本研究以油葵作为研究对象,进行了原油-氯化钠-脱硫石膏盆栽正交试验和煤渣-沸石-脱硫石膏-锯沫盆栽正交试验.结果表明: 在盐渍化条件下,随着原油浓度的增大,油葵幼苗株高相对生长率(RGR)、地上生物量RGR、根氮磷比均显著减小,超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性呈先增加后显著降低的趋势;随着锯沫体积分数的加大,油葵株高RGR和地上生物量RGR均显著增加,SOD活性逐渐降低,说明锯沫在改良盐渍化原油污染土壤方面比煤渣、沸石和脱硫石膏效果显著.在盐渍化条件下,原油污染能够降低油葵幼苗的生长率,锯沫对改良原油污染有较好的效果.     

盐胁迫对黄独脱毒苗生长和若干生理生化指标的影响

通过在培养基中添加不同浓度NaCl,探讨盐胁迫对黄独脱毒苗生长及若干生理生化指标的影响。结果表明,在盐胁迫条件下,黄独脱毒苗的生长受到明显抑制,叶片中总叶绿素含量、SOD活性下降,丙二醛含量增加,脯氨酸大量积累;随盐胁迫强度的加大,对试管苗生长及生理生化指标的影响相应加剧;在盐胁迫下,黄独脱毒苗叶片脯氨酸含量与丙二醛含量呈极显著正相关,而与叶绿素含量和SOD活性呈极显著负相关。因此,盐胁迫下叶片中脯氨酸含量的变化可作为黄独脱毒苗受害程度的主要生理签定指标。     

枸杞LmP5CS基因的克隆及表达分析

目的:为进一步研究枸杞抗逆境胁迫的机制,并为转基因育种,提供理论依据。提高农作物的抗逆性提供优质的基因资源。方法:提选取盐胁迫后脯氨酸含量变化较大的耐盐植物枸杞为材料,用1.5%NaCl处理后,提取枸杞叶片总RNA,利用 RT-PCR 及3' RACE方法克隆获得吡咯啉-5-羧酸合成酶(delta 1-pyrroline-5-carboxylate synthetase,P5CS)基因的全长cDNA,命名为LmP5CS,构建pH7m24GW,3rc-LmP5CS植物表达载体。结果:LmP5CS基因的ORF长2 154 bp,编码1个等电点为6.07、分子量为 77.5kDa、由717个氨基酸组成的蛋白。枸杞在200 mmol/L NaCl 盐胁迫下, LmP5CS基因表达量随处理时间,有先升高后降低的趋势,9h基因表达量最高,脯氨酸含量变化与之一致。结论:LmP5CS基因在盐胁迫下脯氨酸含量的变化中起关键作用。     

Exogenous ABA induces salt tolerance in indica rice (Oryza sativa L.): The role of OsP5CS1 and OsP5CR gene expression during salt stress

Abscisic acid (ABA) applied exogenously at 100 μM prior to and during the salt-stress period induced salt tolerance in both the salt-susceptible (LPT123) and the genetically related salt-resistant (LPT123-TC171) rice lines, enhanced the survival rate by 20%, and triggered proline (Pro) accumulation earlier than that by salt-stress alone, supporting a role for Pro as an osmoprotectant. In both rice lines, salt-stress induced OsP5CS1 gene expression, suggesting that proline accumulation occurs via OsP5CS1 gene expression during salt stress. An increase in the endogenous ABA level was required for the induction of OsP5CS1 gene expression by salt stress. Under salt stress, topical ABA application-induced OsP5CS1 gene expression only in the salt-resistant line but up-regulated OsP5CR gene expression in both rice lines, suggesting that the increased proline accumulation and salt resistance induced by topical ABA application may result from the up-regulation of OsP5CR and not, directly at least, from OsP5CS1. Moreover, exogenous ABA application up-regulates OsCam1-1 (the salt-stress-responsive calmodulin) gene expression, and calmodulin was shown to play a role in the signal transduction cascade in proline accumulation during salt stress. These data suggest the role of the calmodulin signaling cascade and the induction of OsP5CR gene expression in proline accumulation by exogenous ABA application.     

Effects of various salt-alkaline mixed stresses on Aneurolepidium chinense (Trin.) Kitag.

The stress conditions of salt-alkalinized soil were simulated to investigate the features and acting factors of salt-alkaline mixed stress, using a natural salt-alkaline tolerant grass Aneurolepidium chinense (Trin.) Kitag. According to the features of salt-alkalinized soil in the northeast of China, various salt-alkali conditions with different salinities and pHs were established by mixing NaCl, NaHCO₃, Na₂SO₄, and Na₂CO₃, in various proportions. The treatments included a salt concentration range of 50 to 350 mM and pH values from 7.14 to 10.81. Seedlings of A. chinense were stressed under these salt-alkali conditions. Several physiological indices of seedling stress were determined, including survival rate, tillering rate, number of rhizomes, relative growth rate (RGR), proline content, electrolyte leakage rate, and Na⁺ and K⁺ content, in order to analyze the characteristics of the stresses due to the salt-alkali mixes and their main stress factors.The results showed that the survival rate, tillering rate, number of rhizomes, RGR, and K⁺ content of A. chinense decreased with increasing salinity and pH (or alkalinity). Proline and Na⁺ content and electrolyte leakage rate increased with increasing salinity and pH (or alkalinity). The deleterious effects of a high pH value or salinity alone were significantly less than those of high pH in combination with salinity. This result suggested that for a salt-alkaline mixed stress, a reciprocal enhancement between salt stress and alkali stress was a characteristic feature, and it was most evidently reflected in the survival rate. When salinity was below 125 mM or pH was below 8.8, survival rates were all 100%. However, when salinity was above 125 mM and pH was above 8.8, survival rates sharply declined with the increasing of either salinity or pH.The buffer capacity of the treatment solution was taken as a stress factor in order to simplify the stress factor analysis. The results of the statistical analysis showed that for the stress factors of the salt-alkaline mixed stress, [CO₃^2–] and [HCO₃^–] could be fully represented by the buffer capacity, and [Na⁺] could be fully represented by salinity, whereas [SO₄^2–] was negligible. Therefore, four factors, salinity, buffer capacity, pH and [Cl^–], could reflect all of the stress factors. Perfect linear correlations were observed between all physiological indices and four or three stress factors by a stepwise regression analysis. However, the effects of the four stress factors on the physiological indices were significantly different in magnitude. Buffer capacity and salinity were dominant factors for all physiological indices. Thus, it is reasonable to consider the sum of salinity plus buffer capacity as the strength value of salt-alkaline mixed stress. Furthermore, the relationships between different physiological indices and various stress factors were shown to be different.