植物叶钾离子（K+）渗出量变化规律及其在大气质量评价中应用

本文以7个阔叶树种为材料,经SO2熏气证实：植物叶K+渗出量与培养液K+浓度和叶片K+含量无关,依光强和植物种类而异,气孔开度大、叶片含硫量高者K+渗出量也多,具有很强的相关性。基于上述规律,提出按刺槐叶K+渗出量的阈值法和统计法(X±S)划分四个污染等级,用来评价沈阳市的污染状况,与理化监测相比基本一致。据大气SO2浓度(ŷ)与K+渗出量(x)之间建立的相关方程：ŷ=0.0111x-0.0259(r=0.879,P<0.01)计算1982和1983年度大气SO2浓度,并按95%置信度绘制预测图,经精度分析,较理化监测更为稳定可靠。     

运城盐湖十种耐盐植物体内无机及有机溶质含量的比较研究

运城盐湖的 1 0种耐盐植物体内的有机及无机溶质含量差异较大。总无机溶质含量在各种植物间的变化幅度小于总有机溶质 ,其中双子叶植物 (除二色补血草外 )地上部 K+ 含量及 K/Na比均低于单子叶植物 ,而双子叶植物地上部的Na+ 含量明显高于单子叶植物。双子叶植物 (除二色补血草外 )的 Na/Cl>1 ,而单子叶植物的 Na/Cl≈ 1。二色补血草的二价离子 Ca2 +和 Mg2 +含量较高。单子叶植物的可溶性糖及游离氨基酸含量高于双子叶植物 (除枸杞外 ) ,碱莞、盐角草、盐地碱蓬、碱地肤、二色补血草的脯氨酸含量均较低 ( <7μmol/g FW) ,且脯氨酸占游离氨基酸的比例高于其它植物。另外还计算了各种溶质占 COP的百分比 ,并讨论了它们在植物渗透调节过程中的作用。     

盐生植物海马齿耐盐的生理特性

以盐生植物海马齿为研究材料,分别用淡水、1/4海水、1/2海水、全海水浇灌15 d和30 d,研究盐生植物耐盐的生理特性和机理。海马齿植物在低于1/2的海水浇灌时,植物生长旺盛,主要表现为叶片增大和变厚,地上部分生物量增加;而全海水抑制了植物的生长。在盐胁迫下,海马齿植物中Na+的含量叶中最高,茎中含量次之,根中含量最低。长时间盐胁迫时,海马齿植物根、茎、叶中的相对含水量与淡水浇灌相比,变化不大,叶中略有增加;而脯氨酸含量显著增加,且可溶性糖的含量也比淡水浇灌的高。由此推测:海马齿植物主要以有机小分子作为渗透调节物质来维持细胞渗透压,在其耐盐中起着重要的作用。土壤中Na+的毒害,并没有减少土壤中可被植物利用的可交换K+,反而使其增加,说明海马齿植物根部对Na+的吸收能力和Na+/K+交换能力非常强。海马齿植物耐盐性强,还表现为能阻止盐胁迫对植物细胞原生质膜的氧化损伤,不破坏植物叶片内叶绿素的合成,能基本维持植物茎、叶中K+和根、茎中Mg2+的相对稳定。     

树木气孔浸润级与SO2伤害及ABA的防护作用

以常见绿化树种为材料,通过实地测定和熏烟实验,探讨了气孔浸润级与树木SO2伤害的关系及ABA的防护效应.结果表明,在特定环境下,相同树种的气孔浸润级较为稳定,不同树种的气孔浸润级差异较大;浸润级与叶绿素结合度呈负相关变化,但不明显;与K+渗出量呈正相关(r=0.92,α＜0.01),并按95%的置信度绘制了伤害预测图.不同SO2浓度条件下,对同一树种的气孔浸润级的影响甚小,不超过一个等级,K+渗出量则依大气SO2浓度和树木吸S量的增加而增多.气孔浸润级依ABA溶液处理浓度增大而降低,K+渗出量也相应减少,经2.5mol     

喜钙和嫌钙植物对外源Ca2+的生长生理响应

以喜钙植物伞花木和嫌钙植物大白杜鹃为实验材料,以Hoagland营养液并设置其Ca2+浓度分别为0、5、10、25、50mmol/L培养试验,比较不同浓度外源Ca2+对其生长、叶绿素含量、渗透调节和矿质元素积累的影响,探索喜钙植物生长的适应特征,为喀斯特地区喜钙植物嗜钙机制研究提供基础资料。结果显示:(1)随着外源Ca2+浓度的增加,伞花木植株高度、茎粗以及叶干重、叶长、叶宽和叶形指数均得到不同程度提高,叶绿素和可溶性蛋白质含量增加,脯氨酸和可溶性糖含量无显著变化;而嫌钙植物大白杜鹃的生长却受到抑制,叶绿素和蛋白质含量降低,脯氨酸和可溶性糖含量增加;当Ca2+浓度为50mmol/L时,伞花木叶绿素和蛋白质含量分别为2.99mg/g和17.10mg/g,大白杜鹃叶绿素和蛋白质含量分别为1.39mg/g和14.30mg/g。(2)在实验设置的钙范围内,Ca2+可促进伞花木对P、N吸收并稳定体内Ca、K动态;而低浓度的Ca2+(<10mmol/L)促进大白杜鹃对Ca累积,抑制N、P吸收。     

福建梅花山57种常绿树叶片叶绿素特征分析

选取福建梅花山海拔1200m和455m地区57种常绿植物为研究对象,测定两海拔的植物叶片叶绿素a和叶绿素b含量,并计算叶绿素a/b、总叶绿素含量。结果表明:(1)植物叶绿素a、b,叶绿素a+b及叶绿素a/b值大多分布在一个相对集中的区域。(2)多数植物新叶叶绿素含量高于老叶,叶绿素a/b值低于老叶,但是新、老叶无显著差异。(3)不同海拔的植物叶片总叶绿素含量和叶绿素a/b值有明显差异,低海拔地区明显高于高海拔地区。植物通过总叶绿素含量和a/b值的变化以适应不同环境条件。     

高盐生境中乌拉尔甘草盐离子分泌与积存格局的研究

采用植物水培方法,以乌拉尔甘草为研究材料,用不同浓度(0、80、160、320mmol·L~(-1))NaCl溶液胁迫处理乌拉尔甘草幼苗3周后,分析其叶片表面盐离子(K~+、Ca~(2+)、Na+)分泌速率的差异,并采集盐化低地草甸重盐土生境中2年生乌拉尔甘草植株,应用ICP-AES测定其不同部位(根、根状茎、茎、老叶和幼叶)中的盐离子(K~+、Na~+、Ga~(2+)、Mg~(2+))含量,探究盐离子在乌拉尔甘草叶片上的分泌格局以及盐离子在植株体内的积存格局,为完善甘草耐盐机理的研究提供依据。结果显示:(1)随着盐胁迫浓度的升高,乌拉尔甘草叶片上K~+、Ca~(2+)、Na+的分泌速率均呈增加趋势,且Na~+的分泌速率远远大于Ca~(2+)和K+的分泌速率。(2)在乌拉尔甘草各部位中,K+的积存量从大到小依次为:幼叶根根状茎茎老叶;Na~+在各个部位的积存量都十分有限,且无论地下部分还是地上部分,差异均不大;Ca~(2+)积存量由大到小依次为:老叶幼叶茎根状茎根,且老叶中Ca~(2+)的积存量显著高于其它部位。研究认为,在重盐碱地生境中,K+主要积存在幼叶中,Ga~(2+)主要积存在老叶中,植株体内各个部位Na~+的积存量很低,乌拉尔甘草表现出明显的拒Na现象;叶片分泌的主要盐离子为Na~+;乌拉尔甘草通过泌盐的方式将Na+排出体外,从而有效降低Na~+在体内的积存,这是其能够在重盐碱地生存生长的重要原因。     

常夏石竹耐盐突变体渗透调节的研究

在离体培养条件下利用γ-射线作诱变剂获得耐0.5%、0.7%、1.0%NaCl的突变系,通过对稳定突变系植株叶片渗透剂含量及对渗透势贡献大小的测定表明耐盐突变体叶中K+、游离氨基酸、Na+、脯氨酸的含量高于对照,其中脯氨酸和Na+积累最明显。而叶片中可溶性糖的含量、K+/Na+低于对照。Na+对突变体植株叶片渗透势贡献最大,是最主要的渗透调节剂之一。耐盐突变体植株内存在渗透物质的再分配,叶内有吸钾排钠现象。     

松嫩平原草原5种耐盐牧草体内K+, Na+ 的分布与积累的研究

 本文对松嫩平原盐碱化草地生长的5种耐盐牧草羊草(Aneurolepidium chinense)、星星草(Puccinelia tenuiflora)、虎尾草(Chloris virgata)、獐茅(Aeluropus littoralis var. sinensis)和碱蓬(Suaeda glauca)体内K+、Na+的积累与分布动态进行研究。结果表明,植物体内含量Na+μmol／克干重,碱蓬最高为5419—5668,其次是獐毛为225—326和星星草为177—216,虎尾草和羊草变化较大,分别为20—699和11—217。体内Na+含量受土壤中Na+水平的影响。Na+／K+以碱蓬最大为10.47—25.74。随着土壤盐含量(x1)、pH(x2)的增加,羊草和虎尾草体内Na+μmol／克干重(Y)积累动态符合公式：Y=Ym/[1+e(a+b1x1+b2x2)],碱蓬、星星草獐毛符合公式Y=a+b1x1+b2x2。植物体内Na+的积累率依次为：虎尾章>羊草>星星草、獐毛和碱蓬。K+主要分布在代谢旺盛的幼嫩组织中。茎叶是Na+的主要积累部位。虎尾草各部位Na+的积累率均呈显著增大,同时K+均降低,碱蓬各部位K+积累率均随Na+积累而增大。     

盐生植物盐爪爪的耐盐生理特性探讨

当前土壤盐渍化日益严重,是限制植物生长的一个主要环境因子,然而在盐碱自然环境中生长着许多耐盐植物,为更好地了解盐生植物的耐盐机理,该文从无机离子Na+,K+,Ca2+含量、脯氨酸水平、水势变化、丙二醛含量和盐胁迫的表型等生理参数以及半定量RT-PCR检测脯氨酸合成关键酶基因(P5CS)的表达规律等方面探讨盐胁迫下盐爪爪的耐盐特性。结果表明:(1)随着盐浓度的升高,Na+在根和肉质化的叶中显著地富集,且叶中积累的Na+比根中更多;(2)在盐胁迫条件下,随着盐浓度的增加,脯氨酸的含量和脯氨酸合成关键酶基因的表达显著地增强;(3)Na+和脯氨酸是植物有效的渗透调节剂,可使处于低水势的植物细胞仍能从细胞外高浓度的盐溶液中吸收水分;(4)在0和700 mmol·L-1Na Cl处理下,盐爪爪肉质化叶中丙二醛的含量较其它处理高,这表明植物在这两个处理下可能受到了氧化胁迫;(5)从盐胁迫3个月的生长表型来看,低盐环境中生长的盐爪爪植株的生物量更多,肉质化的叶嫩且绿。综上所述,结合对野外生境的调查和实验室长期的盐胁迫表型结果表明盐爪爪的生长是需盐的,相对低的盐浓度环境对盐爪爪的生长是顺境,而无盐或高浓度盐环境对于盐爪爪的生长来说都是逆境。该研究结果为全面深入研究盐爪爪的耐盐特性,以及更好地利用盐爪爪的生物和基因资源改良土壤和提高作物和林木的耐盐性奠定基础。     

Proline accumulation inTephrosia purpurea pers

Tephrosia purpurea Pers. was found to accumulate high proline content in dry habitat. The proline content was higher in shoots, especially in leaves, than in roots. Pod walls and young seeds showed the highest proline content. The proline content of young leaves was higher than that of mature and old leaves. During leaf senescencein vitro proline content increased rapidly upto 6 h and further decreased in leaves as well as in leachate. High proline content seems to be positively related with ‘survival capability’ of this plant.     

Growth Adaptability and Salt Tolerance Osmoregulation of Aneurolepidium chinense Grown on Saline Grassland

The growth of Aneurolepidium chinense Kitag. grown on different saline soil of a Northeast grassland of China was studied and the K+,Na+proline and citric acid accumulated in plants or their organs were determined . The results showed that A. chinense had a strong adaptability to saline habitat and could grow on soil with a salt content of 0. 088%--1.63%,and pH ranging from 8.3 to 9.8. Sodium,proline and citric acid were accumulated by plants for osmotic adjustment when the salinity and Na+content of the soil increased. A. chinense absorbed Na+ rapidly from the soil and excluded K+ when the soil Na+ concentration was less than 20 μmol/g. Sodium was adsorbed slowly and K+ remained constant in plants when Na+ concentrations of soil were 20–80 μmol/g,and proline and citric acid contents were markedly increased. Sodium and K+ decreased slightly in plant tissue and organic solutes increased when Na+ concentrations exceeded 80 μmol/g in soil. Most K+ was distributed in young leaves which were metabolically active. The major sites of Na+ accumulation were in the roots and older mature leaves;whereas proline and citric acid accumulation occurred primarily in young leaves,mature leaves and stems. Tillering buds had strong ability to absord and accumulate K+,Na+ and Proline.     

Proline accumulation in a barley mutant resistant to trans-4-hydroxy-L-proline

Five proline analogues were tested for inhibition of the growth of mature barley (Hordeum vulgare L.) embryos in sterile culture. Inhibition by all analogues was relieved by proline. Inhibition by trans-4-hydroxy-L-proline was relieved by low amounts of proline. Twenty thousand mature embryos were dissected from M₂ seeds after sodium azide mutagenesis. Four plants (Rothamsted 5201, 6102, 6901, 6902) were selected with good growth on 4 mM trans-4-hydroxyproline. Properties of mutant R5201 were studied in detail. Selfed progeny of R5201 were all resistant to trans-4-hydroxyproline and also to L-thiazolidine-4-carboxylic acid and trans-3-hydroxy-L-proline but not L-azetidine-2-carboxylic acid. The content of soluble proline in progeny of R5201 was higher in leaves by a factor of up to six-fold. Proline content was measured in the soluble fraction of the terminal 20 mm of 4 d old plants subjected to severe water stress in 40% w/v polyethylene glycol. Leaves of the mutant contained more proline initially and accumulated proline morer rapidly than the parental leaves. As mutant leaves were larger and lost water more rapidly the greater increase in proline may have been caused by more severe water stress. Resistance to trans-4-hydroxyproline in R5201 was due to a single partially dominant nuclear gene.Abbreviations AZC L-azetidine-2-carboxylic acid - HYP trans-4-hydroxy-L-proline - ORN L-ornithine - CIT L-citrulline     

Exogenous proline effects on water relations and ions contents in leaves and roots of young olive

The ability of exogenous compatible solutes, such as proline, to counteract salt inhibitory effects was investigated in 2-year-old olive trees (Olea europaea L. cv. Chemlali) subjected to different saline water irrigation levels supplied or not with exogenous proline. Leaf water relations [relative water content (RWC), water potential], photosynthetic activity, leaf chlorophyll content, and starch contents were measured in young and old leaves. Salt ions (Na⁺, K⁺, and Ca²⁺), proline and soluble sugars contents were determined in leaf and root tissues. Supplementary proline significantly mitigated the adverse effects of salinity via the improvement of photosynthetic activity (Pn), RWC, chlorophyll and carotenoid, and starch contents. Pn of young leaves in the presence of 25 mM proline was at 1.18 and 1.38 times higher than the values recorded under moderate (SS1) and high salinity (SS2) treatments, respectively. Further, the proline supply seems to have a more important relaxing effect on the photosynthetic chain in young than in old leaves of salt-stressed olive plants. The differential pattern of proline content between young and old leaves suggests that there would be a difference between these tissues in distinguishing between the proline taken from the growing media and that produced as a result of salinity stress. Besides, the large reduction in Na⁺ accumulation in leaves and roots in the presence of proline could be due to its interference in osmotic adjustment process and/or its dilution by proline supply. Moreover, the lower accumulation of Na⁺ in proline-treated plants, compared to their corresponding salinity treatment, displayed the improved effect of proline on the ability of roots to exclude the salt ions from the xylem sap flowing to the shoot, and thus better growth rates.     

Photosynthetic responses and proline content of mature and young leaves of sunflower plants under water deficit

In mature and young leaves of sunflower (Helianthus annuus L. cv. Catissol-01) plants grown in the greenhouse, photosynthetic rate, stomatal conductance, and transpiration rate declined during water stress independently of leaf age and recovered after 24-h rehydration. The intercellular CO₂ concentration, chlorophyll (Chl) content, and photochemical activity were not affected by water stress. However, non-photochemical quenching increased in mature stressed leaves. Rehydration recovered the levels of non-photochemical quenching and increased the F_v/F_m in young leaves. Drought did not alter the total Chl content. However, the accumulation of proline under drought was dependent on leaf age: higher content of proline was found in young leaves. After 24 h of rehydration the content of proline returned to the same contents as in control plants.     

Characteristics of L-proline and sodium transport in renal brush border membranes isolated from 7-day-old and adult rats

To explore the nature of differences in uptake by renal brush border vesicles from animals of different ages, vesicles were isolated from 7-day old and adult rats by a Mg-aggregation method. A number of criteria were compared in vesicles from the young and mature animals. The vesicles isolated from animals of both ages appear similar on electron microscopy, in response to osmotic changes, and in uptake kinetics for L-glucose. Despite these parameters which indicate no basic differences between the membranes of young and mature kidney, differences in proline and sodium handling are seen. When compared to the uptake pattern seen in vesicles from adult animals, the height of the sodium gradient-stimulated proline overshoot is diminished and sodium entry is faster in vesicles of the 7-day old rats. These are the same differences which were found in vesicles prepared by differential centrifugation from 7-day old animals. In addition, although sodium efflux was faster from vesicles of immature kidney and mirrored the faster sodium entry, proline efflux was slower. The data indicate a dissociation of proline and sodium fluxes in brush borders of the young rat kidney.     

Effect of Leaf Age on Potassium Efflux and Net Flux in Tomato Leaf Slices

The effects on leaf age on K (⁸⁶Rb) efflux, influx and net fluxinto lamina slices from leaf 7 on a tomato plant (Lycopersiconesculentum Mill.) were determined. The ontogenetic trend inK efflux was dependent on the external K concentration. At externalKCI concentrations between 0.5 and 10.0 mM, K efflux rates increasedduring leaf elongation. Only a small increase in efflux occurredin mature leaves with increasing age. It is suggested that thetonoplast retains its structural integrity through the initialstages of leaf senescence. In fully expanded leaves, a zeronet K flux (a balance between influx and efflux) was achievedat external KCI concentrations between 1.0 and 3.5 mM. The Kcontent of lamina slices from leaves 5 and 13 remained constantwhen bathed in a solution containing 2 to 3 mM K. It is suggestedthat the decline in K concentration in mature tomato leaf tissueis due to a decline in leaf free space K concentrations below1 to 3 mM which would result in a net efflux out of leaf cells. Lycopersicon esculentum Mill., tor ato, free space, ion fluxes, leaf age, leaf ontogeny, potassium     

Proline, Ornithine, Arginine and Glutamic Acid Contents in Detached Rice Leaves

The effects of water stress on the contents of proline, ornithine, arginine and glutamic acid in detached rice leaves were examined. In water stressed leaves, the content of proline was elevated to a content approximately 8-, 14- and 17-fold higher than in control leaves after 4, 8 and 12 h, respectively. We also observed that omithine and arginine contents were much higher under water stress than in control leaves. However, the content of glutamic acid in water stressed leaves was higher after 4 and 8 h and lower after 12 h than that in control leaves.     

Leaf Photosynthesis,Dark Respiration and Fluorescence as Influenced by Leaf Age in an Evergreen Tree,Prosopis Juliflora

P. juliflora trees produce leaves during two growth periods. The first cohort of leaves is produced during spring in cool conditions, while the second cohort is produced during monsoon under warm conditions. I studied photosynthetic characteristics of young, mature, and old leaves of the previous season (monsoon) in the spring season. Maximum net photosynthetic rate of a young leaf was lower than that of the mature and old leaves. The total CO₂ fixed per day by the young leaves was just 36 % of that in the mature leaves while the old leaves fixed 76 % of that of the mature leaf. The total transpiration rate and water use efficiency (WUE) were similar in the mature and old leaves, while they were much lower in the young leaves. Dark respiration rate was maximal in the young leaves as compared to the mature and old leaves. About 92 % of the total CO₂ fixed per day were respired by the young leaves. The diurnal fluorescence characteristics (F/F_m, q _p, and q _N) of the young, mature, and old leaves showed that photochemical efficiency of photosystem 2 during midday decreased more in the young and old leaves than in the mature ones. However, the fluorescence characteristics showed that in all the three leaf types there was complete recovery of the photochemical efficiency at sunset from the midday depression. F_v/F_m in the young and mature leaves also confirmed this. Hence the young and old leaves were photosynthetically less efficient than mature leaves, but they were well adapted to withstand the harsh environmental conditions.