Influence of proline and hydroxyproline on salt-stressed axillary bud cultures of two varieties of potato (Solanum tuberosum)

Summary The effects of exogenously supplied proline and hydroxyproline on the potato (Solanum tuberosum) varieties L.T.8 and Desiree were studied using axillary bud cultures both in the presence and absence of 0.6% salt stress. In both varieties, the effects of exogenously supplied proline and hydroxyproline at 1.0 mM and 2.5 mM were less severe than 0.6% salt alone. At the same time, the accumulation of proline, protein, carbohydrates, sodium, and potassium were similar. However, when both the salt and proline/hydroxyproline were supplied, proline and hydroxyproline provided some measure of protection against salt stress. It is believed that increased proline levels in L.T.8 and increased carbohydrates in Desiree due to the presence of exogenously supplied proline/hydroxyproline were responsible for the additional protection against salt stress in the axillary bud cultures of these varieties.     

The effect of NaCl on proline accumulation in potato seedlings and calli

The effects of salt stress were studied on the accumulation and metabolism of proline and its correlation with Na⁺ and K⁺ content in shoots and callus tissue of four potato cultivars, viz., Agria, Kennebec (relatively salt tolerant), Diamant and Ajax (relatively salt sensitive). Na⁺ and proline contents increased in all cultivars under salt stress. However, K⁺ and protein contents decreased in response to NaCl treatments. The activities of enzymes involved in proline metabolism, Δ¹-pyrroline-5-carboxylate synthetase (P5CS) and proline dehydrogenase (ProDH) increased and decreased, respectively, in response to elevated NaCl concentrations. The changes of P5CS and ProDH activities in more salt sensitive cultivars (Diamant, Ajax) were more than those in the tolerant ones. Then the stimulation of synthesis in combination with a partially increase of protein proteolysis, a decrease in proline utilization and inhibition of oxidation resulted in high proline contents in seedlings and calli under salt stress. In callus tissue, reduced growth and cell size may be partially responsible for high proline accumulation in response to high NaCl levels. However, although the basic proline contents in the seedlings of more salt tolerant cultivars were higher than the sensitive ones, a clear relationship was not generally observed between accumulation of proline and salt tolerance in potato.     

Physiological Mechanisms of <Emphasis Type="Italic">Solanum tuberosum</Emphasis> L. Plants’ Tolerance to Chloride Salinity

The mechanisms of potato (Solanum tuberosum L.) plants’ tolerance to chloride salinity were investigated in cv. Lugovskoi regionalized in Russia. Regenerated plants were produced in vitro from apical meristem and grown on half-strength Murashige and Skoog medium (0.5 MS) using a hydroponic unit in controlled-climate conditions. At the age of six weeks, the plants were exposed to salt stress (50–150 mM NaCl, 7 days). Plant response to salt stress was estimated by growth parameters (fresh and dry biomass of the aboveground and underground parts of plants, linear dimensions of shoot and root, area of leaf surface, and number of stolons) and physiological characteristics (level of photosynthetic pigments, accumulation of sodium, potassium, and calcium ions in the aboveground and underground parts of plants, content of proline, activity of antioxidant enzymes, plant tissue hydration, osmotic potential, and POL). It was found that, in response to salinity, the plants of potato, cv. Lugovskoi, showed a considerable inhibition of growth processes, reduction in chlorophyll a content, and suppression of stolon formation, which points to a rather low salinity tolerance of the cultivar. At the same time, under weak or moderate salt stress, the plants preserved water homeostasis owing to effective osmoregulation, actively accumulated proline that acted as a stress protector, and showed hardly any signs of oxidative stress. It was assumed that low salt tolerance of this cultivar depends on the inability of its root system to retain sodium ions and ensure selective ion transport to the aboveground part of the plant and on inefficiency of the system of sodium ions’ removal from the cytoplasm of leaf cells and their compartmentalization in the central vacuole with the purpose of reducing their toxic effect. The obtained results may be useful for working out a technique of improving salt tolerance of this cultivar by the methods of molecular genetics.     

甘薯愈伤组织对干旱胁迫和盐胁迫的生理反应对比

研究干旱胁迫和盐胁迫对“芦选一号”。日‘薯愈伤组织可溶性蛋白、可溶性糖、脯氨酸含量、SOD活性等的影响,从而在细胞水平上探讨甘薯抵御渗透胁迫的生理机制。并分析甘薯细胞对干旱处理（PEG-6000）和盐处理（NaCl）的反应差异。结果表明,可溶性蛋白质含量在干旱胁迫下缓慢升高,在轻度和中度盐胁迫的生长前期和中期有较大幅度的上升。但后期下降,表明短时间盐胁迫下,Na^＋可能促进可溶性蛋白的合成;MDA在重度干旱胁迫下的含量显著低于重度盐胁迫,而SOD活性显著高于盐胁迫。表明在盐胁迫下细胞膜透性增加的主要原网是膜脂过氧化作用。干旱处理则是PEG-6000脱水的直接结果;重度干旱胁迫下,可溶性糖含量在短期内迅速升高,然后下降,而脯氨酸含量则在胁迫中后期迅速上升。脯氨酸可能有补偿可溶性糖含量降低的作用。     

Quantitative trait loci (QTL) mapping for physiological and biochemical attributes in a Pasban90/Frontana recombinant inbred lines (RILs) population of wheat (Triticum aestivum) under salt stress condition

Salt stress causes nutritional imbalance and ion toxicity which affects wheat growth and production. A population of recombinant inbred lines (RILs) were developed by crossing Pasban90 (salt tolerant) and Frontana (salt suceptible) for identification of quantitative trait loci (QTLs) for physiological traits including relative water content, membrane stability index, water potential, osmotic potential, total chlorophyll content, chlorophyll a, chlorophyll b and biochemical traits including proline contents, superoxide dismutase, sodium content, potassium content, chloride content and sodium/potassium ratio by tagging 202 polymorphic simple sequence repeats (SSR) markers. Linkage map of RILs comprised of 21 linkage group covering A, B and D genome for tagging and maped a total of 60 QTLs with major and minor effect. B genome contributed to the highest number of QTLs under salt stress condition. Xgwm70 and Xbarc361 mapped on chromosome 6B was linked with Total chlorophyll, water potential and sodium content. The increasing allele for all these QTLs were advanced from parent Pasban90. Current study showed that Genome B and D had more potentially active genes conferring plant tolerance against salinity stress which may be exploited for marker assisted selection to breed salinity tolerant high yielding wheat varieties.     

Light-Dark Changes in Proline Content of Barley Leaves under Salt Stress

Proline accumulation in leaves of barley (Hordeum vulgare L. cv. Alfa) seedlings treated with 150 mM NaCl was promoted in the light and suppressed in the dark. The light/dark changes of proline content was enhanced with each 12 h light/12 h dark cycle and the proline content increased steadily. Root and shoot concentrations of Na⁺ and Cl^– in salt treated plants increased about 10 to 25 times as compared to the control. The content of these ions and the content of malondialdehyde were higher in the shoot of seedlings exposed to salt stress for 4 d in the light in comparison with the seedlings exposed to NaCl for 4 d in darkness. Light stimulated both ions and proline accumulation in the leaves and has no effect in the roots. Oxygen uptake was higher in the seedlings kept 4 d in the light which have higher endogenous free proline content. Chlorophyll fluorescence measurements showed that the photochemical activity of PS 2 slightly decreased as a result of salt stress and was not influenced by light regimes during plant growth.     

大穗结缕草幼苗耐盐生理机制及耐盐能力研究

以大穗结缕草为实验材料,采用不同质量分数的NaCl处理后,观察盐胁迫对其生长及生理生化指标的影响.结果表明:随着盐胁迫浓度增大,大穗结缕草幼苗株高、鲜重、干重都逐渐下降,而根容量和根冠比却逐渐上升;随盐胁迫浓度的增大,大穗结缕草幼苗叶片细胞质膜透性和MDA含量逐渐增加,脯氨酸含量持续升高;其多数生长和生理指标在≥2.0% NaCl盐胁迫浓度下与对照差异显著,且此时的脯氨酸含量是对照的10倍以上.研究发现,大穗结缕草幼苗地上部分对盐胁迫更敏感、受害更严重;通过体内脯氨酸积累来减轻渗透胁迫是其可能的耐盐生理机制;2.0%盐胁迫可能是大穗结缕草的最高耐盐浓度.     

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。     

Proteome analysis of potato under salt stress

Because salt stress is a major abiotic source of stress on potato crops, the molecular mechanism of the response of potato plants to salt stress was examined. On exposure to salt, the salt-sensitive cultivar Concord showed a greater reduction in shoot and root length than did the salt-tolerant cultivar Kennebec. For both cultivars, the reduction in the length of shoots was more severe than that of the roots. Salt exposure increased the content of free proline and total soluble sugars in shoots of Kennebec; these remained unchanged in Concord. Proteins extracted from shoots of both cultivars exposed to 90 mM NaCl were separated by two-dimensional polyacrylamide gel electrophoresis: 322 and 305 proteins were detected in shoots of Kennebec and Concord, respectively. Of these, 47 proteins were differentially expressed under NaCl treatment in shoot of both cultivars. Among the differentially expressed proteins, photosynthesis- and protein-synthesis-related proteins were drastically down-regulated, whereas osmotine-like proteins, TSI-1 protein, heat-shock proteins, protein inhibitors, calreticulin, and five novel proteins were markedly up-regulated. These results suggest that up-regulation of defense-associated proteins may confer relative salt tolerance to potato plants.     

Rosmarinic acid ameliorates the negative effects of salinity in in vitro-regenerated potato explants (<Emphasis Type="Italic">Solanum tuberosum</Emphasis> L.)

Salinity causes massive loss of economic crops due to the build-up of toxic salts in shoot. Rosmarinic acid (RA) has been known to prevent the inevitable damage to vital biological molecules under stress. There is an increasing interest, therefore, in the use of polyphenols in crop stress physiology studies. An in vitro regeneration protocol was established using explants of the potato cultivar White Desiree to assess tolerance to salinity at a morphological, cellular, and biochemical level. Additionally, we examined the potential ameliorative effects of RA on growth in salt-stressed potato explants. Based on our observations, we propose a model for the ameliorative effects of a caffeic acid conjugate of α-hydroxyhydrocaffeic acid. Explants of White Desiree showed differential responses to salt and RA supplementation. Salt-stressed and control explants grown in RA-supplemented media showed a pronounced expansion of leaf area, suggesting direct effects of RA on cell elongation in potato explants. Root elongation was less affected by salinity in comparison to shoot elongation. Moderate levels of RA resulted in stimulatory effects on growth. The microscopic examination of leaves and stems indicated the presence of unique trichomes at the early stages of explant growth under RA supplementation, which varied considerably in size, shape, and distribution in response to stress. Our data indicated that RA significantly decreased osmolyte content under stress. Salinity resulted in the biosynthesis of high levels of free proline, carbohydrates, and malondialdehyde (MDA). However, the lower contents of MDA in salt-stressed explants treated with RA indicate that RA possesses anti-lipid peroxidation properties. Our observations provide evidence for the stimulatory effects of RA on cellular growth and the protection of membranes from ion toxicity.     

盐胁迫对海岛棉和陆地棉幼苗生长及生理特性的影响

采用盆栽法,以海岛棉(Gossypium barbadense)品种新海21号、新海34号和陆地棉(G.hirsutum)品种新陆早50号、新陆早57号为材料,探讨了盐胁迫下海岛棉和陆地棉植株的生长、叶绿素含量、净光合速率、蒸腾速率、抗氧化酶活性、渗透调节物质及丙二醛含量变化的差异。结果显示,随着盐浓度的增加,4个供试品种幼苗的生长、叶绿素含量、净光合速率、蒸腾速率均呈不同程度的下降,而过氧化物酶、超氧化物歧化酶及可溶性糖含量随着盐浓度的增加呈先增后降的趋势,脯氨酸和丙二醛含量均上升。不同品种之间,新海21号和新海34号受胁迫的影响程度小于新陆早57号和新陆早50号。在0.6%Na Cl胁迫下,海岛棉和陆地棉品种均表现出较好的耐盐性。而0.8%和1.0%的Na Cl胁迫对4个供试品种的生长抑制作用大,导致新陆早57号和新陆早50号幼苗生长缓慢、叶面积小、干物质积累少甚至死苗。在较高浓度的盐胁迫下,棉花品种幼苗第1片真叶展开受到显著抑制,可以作为棉花耐盐品种的筛选指标。     

NaCl stress causes changes in photosynthetic pigments,proteins, and other metabolic components in the leaves of a true mangrove,<Emphasis Type="Italic">Bruguiera parviflora</Emphasis>, in hydroponic cultures

We studied salt stress-induced biochemical changes in young, hydroponically grown plants of mangrove,Bruguiera parviflora (Rhizophoraceae). Our focus was on the effect of NaCI (applied at 100, 200, 400, or 500 mM) on leaf pigments, total soluble proteins, total free amino acids, carbohydrates, polyphenols, and proline. The total Chi content increased for 14 d after treatment with 100 mM NaCI, then gradually stabilized. At 400 mM, the total Chi content slowly decreased over the 45-d test period. However, the Chia:b ratio remained unchanged in isolated chloroplasts and in leaf tissue. Percent changes in the carotenoids content followed the same trend as for Chi, except for a 1.5-fold decrease during the 400-mM NaCI treatment, compared with the control. The total sugar content increased by 2.5-fold by Day 45 after treatment with 400 mM NaCI, whereas the starch content measured in the same treatment decreased by 40 to 45%. Leaf protein content decreased as salinity increased, which suggests either a possible disruption in the protein synthesis mechanism or, more likely, an increase in proteolytic activity. The total amino-acid pool increased steadily, by four-fold, in the 45-d, 400-mM treatment Both proline and polyphenols accumulated with increasing levels of salinity, which confirms the role of proline as a stress-induced protective metabolite in the adaptive process of this species. Our results showed that a true mangrove such as 8.parviflora can easily be sustained and propagated under low-salinity conditions. At high levels of salinity (~400 mM, beyond which they could not survive), the plants became adapted to salt stress after two to three weeks. During this adaptive period, changes in pigment and protein levels also occurred. The accumulation of proline and polyphenols played a key role in the plant’s stressinduced adjustment to NaCI under hydroponic culture conditions.     

盐胁迫对平欧杂种榛幼苗生长、光合荧光特性及根系构型的影响

以平欧杂种榛3个品种(新榛1号、新榛2号、新榛3号)幼苗为材料,研究不同盐胁迫程度(对照、轻度、中度、重度)对幼苗生长性状、光合荧光特性以及根系构型的影响.结果表明: 3个品种幼苗的新稍长度、基径、叶面积,以及根、茎、叶、总生物量随着盐胁迫的增强而降低,根冠比则增加.中度、重度盐胁迫下3个品种幼苗的净光合速率较对照分别显著降低20.5%和43.2%.轻度、中度、重度盐胁迫下的蒸腾速率和气孔导度较对照分别降低2.0%、16.3%、32.0%和10.2%、35.7%、60.1%.随着盐胁迫的增强,胞间CO₂浓度缓慢上升,水分利用效率呈先上升后下降的趋势,并在轻度盐胁迫下达到最大值.3个品种幼苗的初始荧光随着盐胁迫的增强而升高.最大荧光、最大光化学效率、潜在光化学活性、实际光化学效率、电子传递速率、光化学淬灭系数随着盐胁迫的增强而下降,非光化学淬灭系数则随着盐胁迫的增强先升高后降低.根系构型分析表明,盐胁迫导致3个品种幼苗的根系生物量、长度、表面积和体积下降.同一盐胁迫下,新榛2号各径级根系构型参数的下降幅度低于其他2个品种.平欧杂种榛幼苗生长性状、光合荧光特性以及根系构型参数受品种和盐胁迫程度的双重影响.盐胁迫下新榛2号表现出较强的生长与光合生理适应性,其耐盐性优于其他2个品种.     

The Method of ABA Application Affects Salt Stress Responses in Resistant and Sensitive Potato Lines

The phytohormone abscisic acid (ABA) has been proposed to act as a mediator in plant responses to a range of stresses, including salt stress. Most studies of ABA response apply ABA as a single dose. This may not resemble the prolonged increasing endogenous ABA levels that can occur in association with slowly increasing salinity stresses in nature or field situations. Salt stress response based on method of ABA application was examined in four potato genotypes of varying salt stress resistance: the sensitive ABA-deficient mutant and its normal sibling, a resistant genotype line 9506, and commercial cultivar ‘Norland’ of moderate resistance. ABA was applied by root drench at 0, 50, 75, or 100 μM concentrations through a single dose, or by slowly increasing multiple ABA doses in a sand-based growing system under greenhouse conditions. Salt tolerance was then evaluated after 2 weeks of exposure to 150–180 mM NaCl stress. The method of ABA application had a marked effect on the responses to salt stress. Plant responses to the method of ABA application were differentiated according to (1) growth rate, (2) root water content, and (3) apparent shoot growth response. Under a single dose, growth rate increased in all genotypes under salt stress, whereas slowly increasing multiple ABA applications generally maintained stable growth rates except in the ABA-deficient mutant where there was an upward growth trend. Percent root water content was elevated only under slowly increasing multiple ABA doses in two genotypes, whereas none of the single-dose treatments induced any change. The single ABA dose enhanced vertical growth, whereas the slowly increasing multiple ABA dose applications enhanced lateral shoot growth. Because exogenous application is still an artificial system, endogenous ABA was supplied through grafting of ABA-deficient mutant scions onto rootstocks with known elevated ABA levels. Multiple exogenous ABA applications as low as 50 μM elicited similar shoot water content responses as grafting treatments without ABA application in the mutant genotype but had no effect on the ABA normal sibling. Shoot dry weight was significantly increased through grafting over all exogenous ABA treatments. Our study further indicates that the method of ABA application regime in itself can alter plant responses under salt stress and that certain application regimes may reflect responses to elevated endogenous levels of ABA.     

Alleviation of exogenous oligochitosan on wheat seedlings growth under salt stress

Hydroponic experiments were carried out to study the role of oligochitosan in enhancing wheat (Triticum aestivum L.) resistance to salt stress. Data were collected on plant biomass, chlorophyll content, photosynthetic rate (P _n), stomatal conductance (g _s), proline content, antioxidant enzyme activities, and malondialdehyde (MDA) content. Under 150 mM salt stress, plant growth was significantly inhibited. Shoot length, root length, and dry weight were sharply reduced by 26%, 31%, and 20%, respectively, of the control. Superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were increased by 28%, 13%, and 26%, respectively, of the control and MDA content largely accumulated, which was 1.5-fold of the control. However, 0.0625% oligochitosan pretreatment alleviated the adverse effects of salt stress, which was reflected by increasing root length, shoot length, dry weight, chlorophyll content, P _n, and g _s. Furthermore, it also showed that oligochitosan pretreatment significantly increased antioxidant enzyme (SOD, CAT and POD) activities, and reduced MDA content in leaves. Meanwhile, the accumulation of proline was markedly accelerated. The results indicated that oligochitosan pretreatment ameliorated the adverse effects and partially protected the seedlings from salt stress during the following growth period.     

Improved growth of salinity-stressed soybean after inoculation with salt pre-treated mycorrhizal fungi

Two sets of experiments to determine the effect of mycorrhiza on soybean (Glycine max) growth under saline conditions and to investigate the salt acclimation of mycorrhizal fungi were conducted. In the first experiment, the effect of an arbuscular mycorrhizal (AM) fungus Glomus etunicatum on mineral nutrient, proline and carbohydrate concentrations and growth of soybean. Under different NaCl concentrations (0, 50, 100, 150 and 200mM) was evaluated. Salinity decreased AM colonization. In both the M and nonAM plants shoot and root proline and shoot Na and Zn concentrations were increased under salinity. Soybean plants inoculated with the AM fungus had significantly higher fresh and dry weight, root proline, P, K and Zn but lower shoot proline and Na concentrations compared to the non inoculated plants. In the second experiment, the AM fungus was pre-treated with NaCl (salt acclimation) then was used as inoculum for soybean plants subjected to 100mM NaCl. Root colonization, fresh and dry weight, root proline, P, K and Zn concentrations were greater in soybean plants inoculated with the salt pre-treated fungus, compared to those inoculated with the nonsalt pre-treated fungus. However, for Na, the situation was the opposite. Based on these results, the AM inoculation helps the growth of soybean plants grown in saline conditions. When the AM fungus was pre-treated with NaCl with a gradual increase of concentration, and then exposed to a sudden salt stress, their efficiency was increased. This may be due to the acclimation of the AM fungus to salinity.     

Physiological and biochemical adaptations of Cynodon dactylon (L.) Pers. from the Salt Range (Pakistan) to salinity stress

Naturally adapted salt tolerant populations provide a valuable material for exploring the adaptive components of salt tolerance. Under this aspect, two populations of Cynodon dactylon (L.) Pers. were subjected to salt stress in hydroponics. One was collected from a heavily salt-affected soil in the vicinity of a natural salt lake, Uchhali Lake, in the Salt Range of the Punjab province of Pakistan, and the other from a normal non-saline habitat from the Faisalabad region. The NaCl treatments in Hoagland's nutrient solution were: Control (no salt), 50, 100, 150 and 200 mM of NaCl. After 8 weeks of growth in hydroponics produced biomass, ion relations, and photosynthetic capacity were measured in the differently adapted ecotypes. In the ecotype of C. dactylon from the Salt Range, shoot dry weight was only slightly affected by varying levels of salt. However, in contrast, its root weight was markedly increased. On the other hand, the ecotype from Faisalabad (non-saline habitat) showed a marked decrease in shoot and root dry weights under saline regimes. The ecotype from the Salt Range accumulated relatively less amount of Na⁺ in the shoot than did that from Faisalabad, particularly at higher salt levels. Shoot or root K⁺ and Ca²⁺ contents varied inconsistently in both ecotypes under salt stress. All the photosynthetic parameters, leaf water potential and osmotic potential, and chlorophyll content in both ecotypes were adversely affected by salt stress, but all these physiological attributes except turgor potential and soluble sugars were less affected at high salinities in the salt tolerant ecotype from Salt Range. This ecotype accumulated significantly higher organic osmotica (total free amino acids, proline, total soluble proteins, and total soluble sugars) under saline conditions than its intolerant counterpart. Overall, the salt tolerant ecotype of C. dactylon from the Salt Range showed high salt tolerance due to its restricted uptake of Na⁺ accompanied by an increased uptake of K⁺ and Ca²⁺ in the roots as well as shoot due to its higher photosynthetic capacity and accumulation of organic osmotica such as free amino acids and proline under saline conditions.     

甜菜耐盐性筛选及其幼苗对盐胁迫的响应

为了探讨甜菜耐盐机理、不同耐盐等级甜菜盐耐性机制差异,对40份甜菜品种（系）用300mmol·L-1NaCl胁迫处理,通过芽期相对盐害率和苗期盐害指数确定不同品种耐盐等级,将不同耐盐等级材料进行NaCl浓度梯度（150、300mmol·L-1）处理,测定植株鲜重、超氧化物歧化酶（SOD）活性、丙二醛（MDA）含量和叶片质膜透性。试验结果如下：40份甜菜材料经过芽期和苗期耐盐性筛选最终确定耐盐等级极强的品种（系）1份（‘KWS0143’）,耐盐等级强的品种（系）6份（‘ACERO’等）,耐盐等级中等的品种（系）14份（‘HI0183’等）,耐盐等级弱的品种（系）5份（‘OVITO’等）;在同一盐胁迫时间下,不同耐盐等级材料的植株鲜重随盐浓度的增加呈下降趋势,品种‘KWS0143’和‘ACERO’变化幅度较小,品种‘OVATIO’下降幅度最大;不同耐盐等级材料随盐浓度增加和胁迫时间延长超氧化物歧化酶（SOD）活性呈现先上升而后下降的趋势,耐盐性极强的品种酶活性显著高于其他耐盐等级材料;不同耐盐等级材料随盐浓度增加和胁迫时间延长丙二醛（MDA）含量和叶片质膜透性均呈上升趋势,耐盐等级弱的品种（系）明显高于其他各个材料。     

Salt Tolerance of Solanum tuberosum L. Overexpressing an Heterologous Osmotin-like Protein

Potato (Solanum tuberosum L. cv. Bintje) was transformed with a cDNA clone encoding an osmotin-like protein. Transgenic and non-transgenic in vitro plants were subjected to NaCl for 3 weeks. The shoot and root development was slightly affected by salinity indicating that the salt condition used was a mild stress. The endogenous proline content of the osmotin-like transformed clone only raised slightly as compared to the non-transformed genotype, where a marked increase in proline content could be observed as a result to salt stress. These data provide evidence for the involvement of osmotin-like proteins in the mechanisms of salt tolerance in potato plants. This revised version was published online in July 2006 with corrections to the Cover Date.     

葡萄砧木耐盐性与丙二醛和脯氨酸关系的研究

采用水培法,对3个不同耐盐性葡萄砧木品种的1年生苗进行不同浓度的NaCl胁迫处理,研究叶片中丙二醛(MDA)和脯氨酸(Pro)含量的变化.结果表明,在NaCl胁迫下,不同耐盐性葡萄砧木品种的MDA和Pro含量变化不同.NaCl胁迫对高抗品种ZM01-1的MDA含量影响较小,MDA含量处于一个比较稳定的水平,而其它品种的MDA变化幅度大;NaCl胁迫下Pro含量呈波动式变化,在0.1%NaCl胁迫下高抗品种ZM01-1的Pro积累少,0.3%NaCl下ZM01-1的Pro积累多.研究认为可以把MDA含量的相对稳定作为葡萄耐盐性鉴定的辅助指标,而Pro不宜作为葡萄耐盐性鉴定指标.