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The occurrence and development of riparian forests, which were mainly dominated by mesophytes species related closely with
surface water. Since there was no water discharged to the lower reaches of Tarim River in the past three decade years, the
riparian forests degrade severely. The groundwater table, the saline content of the groundwater, as well as the content of
free proline, soluble sugars, plant endogenous hormones (abscisic acid (ABA), and cytokinins (CTK)) of the leaves and relative
rates of sap flow of the Populus euphratica Oliv. (arbor species), Tamarix ramosissima Ldb. (bush species), and Apocynum venetum L. (herb species) were monitored and analyzed at the lower reaches of the Tarim River in the study area where five positions
on a transect were fixed at 100 m intervals along a sampling direction from riverbank to the sand dunes before and after water
release. The physiological responses and acclimation strategies of three species to variations in water and salinity stress
were discussed. It was found that A. venetum population recovered to groundwater table ranging from −1.73 to −3.56 m, and when exposed to saline content of the groundwater
ranging from 36.59 to 93.48 m mol/L; P. euphratica appeared to be more sensitive to the elevation of groundwater table than the A. venetum and T. ramosissima at groundwater table ranging from −5.08 to −5.80 m, and when exposed to saline content of the groundwater ranging from 42.17
to 49.55 m mol/L. T. ramosissima tended to be the best candidate species for reclamation in this hyper-arid area because it responded to groundwater table
ranging from −1.73 to −7.05 m, and when exposed to saline content of the groundwater ranging from 36.59 to 93.48 m mol/L.
These results explained the distribution patterns of desert vegetation in the lower reaches of the Tarim River. Understanding
the relationships among ecological factors variables, physiological response and acclimation strategies of plant individuals
could provide guidance to sustainable management, reclamation and development of this and similar regions. 相似文献
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One-month old Zygophyllum xanthoxylon seedlings were grown under five different Ni concentrations (0, 50, 150, 450 and 900 mg/kg). Growth parameters, tissues Ni accumulation, soluble protein content, photosynthetic pigment content, lipid peroxidation, antioxidative enzyme activities, and proline content were studied after one month of Ni exposure. The significant reduction in fresh biomass in the shoot and roots was detected at high Ni concentrations (≥450 mg/kg), whereas dry biomass was not significantly affected in both organs by any of the Ni doses tested. The Ni contents in the shoots and roots increased in a dose-dependent manner, and Ni contents in roots were higher than that in shoots at all treatments. The high Ni doses elevated soluble protein contents in leaves and roots. No visible symptoms of chlorosis were observed in leaves of plants grown in presence of Ni. Malondialdehyde (MDA) contents significantly increased in leaves and roots at high Ni treatments (≥450 mg/kg), indicating that Ni induces oxidative stress. Enzyme activities might play a central role in cellular protection against the Ni induced oxidative stress. Proline contents proportionally increased with the elevated Ni concentrations. Zygophyllum xanthoxylon revealed moderate Ni tolerance under tested culture conditions, and could be used as tools for revegetation for erosion control in moderate Ni contaminated sites. 相似文献
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ZHANG Kaikai MAI Kangsen XU Wei ZHOU Huihui LIUFU Zhiguo ZHANG Yanjiao PENG Mo 《中国海洋大学学报(英文版)》2015,14(3)
This study was conducted to investigate the effect of dietary proline(Pro), and Pro and hydroxyproline(Hyp) in combination on the growth performance, total Hyp and collagen concentrations of tissues, and prolyl 4-hydroxylase α(I)(P4H α(I)) gene expression in juvenile turbot feeding high plant protein diets. A diet containing 50% crude protein and 12% crude lipid was formulated as the basal and control, on which other two protein and lipid contents identical experimental diets were formulated by supplementing the basal with either 0.75% Pro(Pro-0.75) or 0.75% Pro and 0.75% Hyp(Pro+Hyp). Four groups of fish in indoor seawater recirculating systems, 35 individuals each, were fed twice a day to apparent satiation for 10 weeks. The results showed that dietary Pro and Hyp supplementation had no significant effect on growth performance and feed utilization of juvenile turbot(P 0.05). Total Hyp and collagen concentrations in muscle were significantly increased when dietary Pro and Hyp increased(P 0.05), and fish fed diet Pro+Hyp showed significantly higher free Hyp content in plasma than those fed other diets(P 0.05). The expression of P4 H α(I) gene in liver and muscle was significantly up regulated in fish fed diet Pro-0.75 in comparison with control(P 0.05); however the gene was significantly down regulated in fish fed diet Pro+Hyp in muscle in comparison with fish fed diet Pro-0.75(P 0.05). It can be concluded that supplement of crystal L-Pro and L-Hyp to high plant protein diets did not show positive effects on growth performance of juvenile turbot, but enhanced total collagen concentrations in muscle. 相似文献
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阿拉善荒漠区几种抗旱植物游离氨基酸和游离脯氨酸的分布特征 总被引：14，自引：14，他引：14
以阿拉善荒漠区生长的多浆旱生植物梭梭(Halox ylon ammodendron)和霸王(Zygophyllum xanthoxylure)、少浆旱生植物白沙蒿(Artemisia sphaerocephala)和柠条(Caragana korshinskii)、中旱生植物沙米(Agriophyllum squarrosu)和绵蓬(Corlsperrnum mongolicum)为材料，对其游离氨基酸成分及游离脯氨酸的分布特征进行了比较研究。结果表明，供试植物根中的总游离氨基酸含量均低于茎和叶中的总游离氨基酸含量，其中叶中的游离氨基酸总量最高；不同植物中的主要氨基酸组成不相同，同一植物的不同部位主要氨基酸组成也不尽相同。少浆旱生植物体内大量积聚游离脯氨酸，其整株中的游离脯氨酸是中旱生植物的6．0～16．0倍，是多浆旱生植物的1．8～25．0倍。白沙蒿植株的根到茎、茎到叶，总游离氨基酸含量以2．0倍和5．7倍的增幅增加，其中游离脯氨酸含量增加最明显，增幅达3．0倍和10．5倍。柠条植株也表现出同样的趋势。可见，大量积累游离氨基酸，特别是游离脯氨酸是少浆旱生植物适应干旱荒漠生境的重要机制。从根到茎、由茎到叶，中旱生植物沙米和绵蓬与多浆旱生植物梭梭和霸王总游离氨基酸含量增幅都并不十分显著；二者中的游离脯氨酸积累不占主导地位。故中旱生植物和多浆旱生植物并不主要依靠积累脯氨酸来调节渗透势确保水分的供应。 相似文献
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干旱胁迫下的胡杨脯氨酸累积特点分析 总被引：18，自引：4，他引：18
以塔里木河下游的主要乔木-胡杨为研究样本，结合野外地下水位临测资料，详细分析了塔里木河下游干旱胁迫环境下胡杨体内脯氨酸的累积与变化。分析研究表明，胡杨体内的脯氨酸含量与塔里木河下游地下水位变化存在密切，脯氨酸含量随地下水位降低而增加，二者相关系数达0．913；在不同地下水位埋深条件下。脯氨酸含量的增加幅度有差异；胡杨体内的脯氨酸含量随干旱胁迫的加深而积累，是胡杨对干旱逆境的一种反应。表明塔里木河下游胡杨的生长发育已受到严重的干旱胁迫。 相似文献
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通过对抗逆性不同的6个烟台冬小麦品种在盐处理和干旱胁迫交互作用进程中叶片相对含水量（RWC）,膜脂过氧化产物（MDA）和抗氧化酶活力（SOD,POD,CAT）及渗透调节物含量（脯氨酸,可溶性蛋白）的分析,以了解不同冬小麦品种对盐处理和干旱胁迫交互作用响应的生理调节差异。研究表明,在水分供应充足条件下盐处理10 d,6个品种冬小麦生长良好并和对照没有差异,但在干旱胁迫中盐处理组较对照MDA含量低,RWC和抗氧化酶活力和渗透调节物含量均高,且叶片萎蔫较对照出现晚。但经盐处理的6个冬小麦品种对干旱胁迫响应有差异。在长期干旱(12 d),抗旱性强的品种RWC（81%）明显高于抗旱性弱的（62%）,前者叶片MDA含量较后者低30%,抗旱性强的品种抗氧化酶活力和渗透调节物含量略低于抗旱性弱的品种,但是差异不明显。在盐处理和干旱胁迫交互作用下,盐离子自身可作为渗透调节物既增加了土壤的持水力又提高了细胞保水力而使冬小麦耐旱性增强。抗旱性强的冬小麦品种对盐处理反应敏感且保水性强,细胞膜脂过氧化程度较低,故耐旱力高,抗旱性弱的品种则相反。研究进一步表明,在未来干旱地区实施适度的盐水灌溉可提高冬小麦的耐旱力,但选择抗旱力强的冬小麦品种是实施这一农业耕作措施的关键。 相似文献
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高山冰缘植物游离氨基酸的含量分析 总被引：6，自引：1，他引：5
以乌鲁木齐河源区22种主要高山冰缘植物花期叶片为实验材料, 分析了游离氨基酸含量. 结果表明: 多数高山冰缘植物积累大量游离中性氨基酸, 总游离氨基酸以脯氨酸(Pro)、苏氨酸(Thr)、天门冬氨酸(Asp)、丙氨酸(Ala)和谷氨酸(Glu)为主要成分. 同一植被带不同植物积累游离氨基酸的种类和水平不同, 如高山离子芥(Chorispora bungeana)的游离Pro含量占其总游离氨基酸含量的百分比均高出雪莲、黄花夏至草和黄头小甘菊13倍多, 含量差异明显. 3个植被带植物总游离氨基酸、 Pro和中性氨基酸的平均含量, 高山流石堆植被高于高山垫状植被和高山草甸植被, 高山垫状植被总游离氨基酸和中性氨基酸含量高于高山草甸植被. 高山冰缘植物积累不同种类和不同含量水平的游离氨基酸是对严酷环境的一种适应. 相似文献
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实验检测在不同浓度的盐胁迫及不同的胁迫时间下，海滨香豌豆叶片内脯氨酸、可溶性蛋白和可溶性糖三种成份含量的变化。得出：脯氨酸含量随盐胁迫浓度和胁迫时间变化呈现一定的正相关；可溶性蛋白则呈相对比较稳定的趋势；而可溶性糖则呈无规则变化。这些结果表明，在以上三指标中，脯氨酸对盐胁迫起主要的调节作用。 相似文献