几种水生植物对湿地底泥中营养物质含量变化的影响

采集石佛寺人工湿地5种不同植物区域(空白区域、荷花区域、芦苇区域、蒲草区域、沉水和浮叶植物混合区域)中指定点域的湿地底泥,测出底泥中OM、TN、TP这3种营养物质的含量,并进行其含量变化对比分析。结果表明:影响湿地底泥中营养物质含量的因素有微生物因素、外源污染因素和水生植物因素。3种因素对于底泥中营养物质含量的影响在不同的植物生长期内各不相同。在植物快速生长发育时期,底泥中营养物质受到植物生长吸收的影响最大;在植物平稳生长期,底泥中营养物质受到外界因素影响最大;在植物死亡腐解期,底泥中营养物质受到植物腐解因素的影响最大。不同的温度,对于微生物的影响不同,进而影响底泥中营养物质含量的变化。综合以上结论可知底泥中营养物质含量的变化受植物的影响最大。     

几种沙漠植物蒸腾作用特性及其环境响应机制的研究

对库布齐沙漠2，3，4年生人工梭梭，4年生人工沙枣、柠条以及天然植物油蒿，进行了蒸腾速率与相关环境因子气温、大气相对湿度和0～160cm土层的土壤含水率的测定。结果表明：不同植物种其蒸腾特征各异；气温和大气湿度与蒸腾速率日进程的变化趋势总体表现出随着气温的升高（或大气相对湿度的降低），蒸腾速率亦呈升高的趋势。几种植物蒸腾速率的季节变化总体表现出随着土壤含水率的增加而增加，降低而降低。蒸腾速率与土壤含水率季节变化的相关性因植物种而异。几种植物中油蒿10～100cm层土壤含水率和2年生梭梭、3年生梭梭0～130cm层土壤含水率与蒸腾速率呈直线相关，相关系数分别为0．811，0．694和0．955（P=0．05），而沙枣、柠条和4年生梭梭的蒸腾速率与土壤含水量的相关性不显著。这表明，在天然降水条件下，植物蒸腾作用的季节变化趋势不仅受土壤水分的影响，还与植物自身生长节律和生理调控等其它因素有关。     

Occurrence of Polycyclic Musks in Sewage Sludge and their Behaviour in Soils and Plants. Part 2: Investigation of Polycyclic Musks in Soils and Plants (9 pp)

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Part 2: Investigation of Polycyclic Musks in Soils and PlantsPart 1: Behaviour of Polycyclic Musks in Sewage Sludge of Different Treatment Plants in Summer and Winter

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Preamble. In Part 1 of the study, screening tests were performed to investigate the occurrence of PCM in sewage sludges. For a preliminary risk assessment, further information is needed about their behaviour in the terrestrial environment. Hence Part 2 examined the adsorption of PCMs to soil, their dissipation and leaching in soil and their uptake in plants.

Goal, Scope and Background

Polycyclic Musks (PCMs) enter the terrestrial environment via the use of sewage sludge as fertilizer. After entry into soil, they can be taken up by plants or move into the groundwater body. However, until now no overall risk assessment for polycyclic musks is available. For a preliminary risk assessment further information is needed about their behaviour in the soil environment. Therefore, Part 2 of the study (Part 1, see J Soils Sediments, OnlineFirst ) examined the adsorption of PCMs to soil, their dissipation and leaching in soil and their uptake by plants.

Methods

Analytical methods for the determination of HHCB and AHTN in soil and plant samples were developed and applied. The adsorption/desorption studies were performed according to OECD guideline 106 and draft guideline 121 using three soils. Dissipation (aerobic degradation) was examined according to BBA guideline 4-1 in three soils over a test period of 37 weeks under controlled conditions. Leaching experiments in soil columns were performed using columns of 14 cm Ø and 30 cm filling height for a test period of 48 hours. Finally the uptake of PCMs by lettuce and carrots was studied in laboratory and outdoor experiments.

Results

The adsorption/desorption studies resulted in Koc values between 4200 and 7900 for HHCB and between 4800 and 13600 for AHTN showing strong sorption to the soils investigated. The dissipation of the PCMs occurred very slowly with elimination rates after 37 weeks of approx. 50% and 25% for HHCB and AHTN, respectively. The leaching experiments showed leaching rates of < 0.001% for HHCB and AHTN during a test period of 48 hours. The slight leaching is presumably due to ‘preferential flow'. The transfer factors (ratio of concentrations in the plant to concentrations in the soil ) for HHCB in lettuce and carrot leaves determined in plant uptake experiments were as low as 0.003. For HHCB in carrot roots however high transfer factors of 0.095 for a humic and 0.48 for a loamy soil were obtained. The high uptake may be caused by partitioning of the HHCB into the essential oil cells of the carrot roots.

Discussion

The polycyclic musk compounds HHCB and AHTN showed high adsorption to soil. A desorption phenomenon occurred after three desorption steps. High adsorption influences the slow degradation kinetic. Comparable investigations into the degradation behaviour show the same results, whereas other authors observed a faster degradation. We assume a dependency on microbial consortia, which can vary as a function of the substrate and adaptation of the microbial population. Leaching tests were carried out in our study, but not by other studies. The results reflect the adsorption into the soil matrix.

Conclusions

The results show that PCMs are widespread contaminants in sewage sludge and should be considered in a risk assessment as potential contaminants of sewage sludge destined for agricultural use. When applied to soil they may remain in the upper soil layers due to their high sorption, low degradability and low leaching behaviour. Uptake by some plants like carrot roots may be relevant.

Recommendations and Perspective

. This study examined the adsorption of PCMs to soil, their dissipation and leaching in soil and their uptake into plants. For a qualitative risk assessment more data on adsorption /desorption, and degradation in soils under different soil conditions needs to be generated. Also, further studies have to be carried out to gain a better understanding of plant uptake of PCMs, especially HHCB and AHTN.

     

Occurrence of Organotin Compounds in the Aquatic Environment of Greece

The presence of organotin (OT) compounds was investigated in coastal areas (10 stations), wastewater treatment systems (six stations), rivers (19 stations) and lakes (12 stations) throughout Greece, in three sampling campaigns organized between October 1998 and September 1999. A screening method for the determination of toluene extractable organotins (TEOTs) by Electrothermal Atomic Absorption Spectrometry (ETAAS) was used during the first two sampling campaigns. TEOTs (sum of tributyltin, TBT, dibutyltin, DBT and triphenyltin, TPhT) were detected in most seawater and wastewater samples at concentrations up to 19.4 and 89.9 ng l^?1, respectively, while they were detected occasionally in surface water. During the third sampling campaign, OT compounds were extracted in selected stations using direct derivatization with NaBEt₄ in acidic medium and analysed by Gas Chromatography–Mass Spectrometry (GC–MS). In seawater, the levels of TBT, DBT and monobutyltin (MBT) were varied between < 2 and 70, 159 and 19 ng l^?1, respectively and tend to decrease with increasing distance from the coastline. TPhT was not detected in any of the samples. Significant concentrations of OT species were detected in influent wastewater, up to 384, 76.2 and 67.8 ng l^?1 for TBT, DBT and MBT, respectively. OTs were mainly associated with the suspended solids and were totally removed during wastewater treatment.     

北京市海绵城市试点区雨水花园植物群落生态适应性及其应用效果

[目的] 针对已建成的城市雨水花园项目,从生物多样性的角度进行多指标调查评价,分析雨水花园植物的适应性及景观应用效果,旨在为北京地区雨水花园植物群落优化配置提供科学参考。[方法] 通过实地调研,分析和掌握雨水花园植物群落的多样性特征,在定量分析的基础上构建雨水花园植物群落景观评价模型对15个典型雨水花园植物群落进行分级和评价。[结果] ①北京市海绵城市试点建成区雨水花园草本植物共20科,43属,45种,优势科主要集中于菊科(Compositae)、禾本科(Gramineae)、百合科(Liliaceae)、景天科(Crassulaceae)等。试点区各样地指数数值差异较小,各调查样地草本植物丰富度相似,植物物种集中性较一致。②试点区雨水花园植物群落景观综合评价总体处于较高水平,各样地中小区类雨水花园植物群落评价明显高于道路类雨水花园植物群落景观。受所在区域地表径流污染程度的影响,不同样地植物生长情况、群落构成有所差别。[结论] 未来还需加强对建成雨水花园植物的定期监测、评估,重视开发本土植物,筛选出优势物种,总结出结构稳定的植物群落配置模式与维护管理手段,为北京市雨水花园植物选择与配置提供科学参考。     

植物前体mRNA的选择性剪接

选择性剪接是细胞生物体产生复杂蛋白的一个重要机制。迄今为止，对植物选择性剪接基因的研究远不如动物。尽管如此，仍在选择性剪接的调控机制、剪接特异性和影响因素及剪接功能等方面取得了一定的进展。本文就这方面的研究进展作一简要综述。     

针叶林岩-土-植系统中毒害元素赋存规律研究

以成都天台山及其周边区域马尾松、柳杉、杉木林为研究对象,通过野外调查、室内测试分析,开展了针叶林岩—土—植系统中毒害元素赋存规律研究,结果表明:3种针叶林立地As,Hg元素岩石库风化对土壤地质潜在输入次序为杉木林地、马尾松林地、柳杉林地;5种毒害元素中As,Hg,Cd,Pb4种元素均表现出在土壤表层有累积态势;而As元素在马尾松、柳杉等植物体运移能力强;Hg元素在杉木体内容易迁移;Al元素在杉木、柳杉内部的运输能力高;Pb元素在柳杉、马尾松中有较高的迁移能力;Cd在马尾松内容易发生转移;3种针叶树种对Pb,Hg,Cd的赋存能力高,而对Al,As两种元素的赋存能力较低。     

植物在高速公路边坡防护中的应用

高速公路的建设带来了一系列的生态问题。植物应用于边坡的防护和绿化是防止水土流失、改善公路生态环境、减少生境片段化、保护生物多样性的有效方法。简述了边坡防护的三种方法（工程防护、生物防护、工程结合生物防护），重点介绍了植物在高速公路边坡防护中的作用。讨论了三种方法的适用范围，并阐述了施工中应注意的问题以及后期管理。同时，还提出了植物配置、景观设计中应遵守的一些原则，以及今后的研究方向。     

Nitrogen Metabolism in Tomato Plants Under Cadmium Stress

Abstract

Young seedlings of tomato (Lycopersicon esculentum Mill.) grown on nitric medium and treated with different cadmium (Cd) concentrations (0–50 µM) were used. Results obtained show that Cd remains predominantly located in the roots, which then seem to play the role of trap‐organs. Increasing Cd concentration in the medium leads particularly to a decrease in NO₃ ^? accumulation, together with decrease in the activities of nitrate reductase (NR), nitrite reductase (NiR), and glutamine synthetase (GS). On the other hand, stimulations were observed for ammonium accumulation, anabolitic activity of glutamate dehydrogenase (GDH) and protease activity. Contrarily, decreases were obtained for soluble protein contents and catabolitic activity of GDH. These results were discussed in relation to the hypothesis attributing to the mitochondrial enzyme NADH‐dependent GDH, an important role in the plant defense processes, in maintaining the glutamate pool in conditions where the need for NH₄ ⁺ detoxification is increased by heavy metals.     

植物中铵转运蛋白的研究进展

铵转运蛋白在众多生物中被克隆与鉴定，它是一种广泛存在于微生物、植物细胞及动物的细胞膜上主动转运铵离子的载体，分子量约为48kD，含有10-11个跨膜域。本文阐述了植物铵转运蛋白分离鉴定的过程，对于铵转运蛋白的结构、功能、基因表达调控等方面作了较详细叙述。不同氮素条件下，铵转运蛋白基因通过转录调控表现了对铵离子吸收转运的不同特点，使植物根系在较宽的浓度范围中吸收铵离子，为细胞内铵离子库的内稳态提供了理论依据。铵转运蛋白有助于作物更有效的吸收氮素，为农业生产粮食增收提供了有利保障。     

激素在植物冷胁迫应答中的角色

寒冷是限制植物生长发育的非生物胁迫因子之一。冷胁迫应答过程中,植物内源激素在生理水平和基因表达调控中起重要作用。本文综述了水杨酸、脱落酸、乙烯、茉莉酸、赤霉素和细胞分裂素等激素在植物抵御冷胁迫过程中的作用机制,并对这些激素在植物冷胁迫应答研究中存在的问题进行了讨论,以期为今后通过激素调节提高植物的抗寒性研究提供参考。     

Occurrence of Polycyclic Musks in Sewage Sludge and their Behaviour in Soils and Plants. Part 1: Behaviour of Polycyclic Musks in Sewage Sludge of Different Treatment Plants in Summer and Winter (5 pp)

Background, Aim and Scope   Part 1: Behaviour of Polycyclic Musks in Sewage Sludge of Different Treatment Plants in Summer and Winter Part 2: Investigation of Polycyclic Musks in Soils and Plants -  Preamble. In Part 1 of the study, screening tests were performed to investigate the occurrence of PCMs in sewage sludges. For a preliminary risk assessment, further information is needed about their behaviour in the terrestrial environment. Hence, Part 2 examined the adsorption of PCMs to soil, their dissipation and leaching in soil and their uptake by plants. Background, Aim and Scope   Polycyclic Musks (PCMs) enter the environment via the waste water system. Because of their persistence, they can accumulate in different matrices like sewage sludge or biota. By the use of sewage sludge as a fertilizer, PCMs are transferred to agricultural soils. Therefore, in Part 1 of the study, screening tests were performed to investigate the occurrence of PCMs in sewage sludge. For a preliminary risk assessment, further information is needed about their behaviour in the terrestrial environment. Hence, Part 2 of the study examined the adsorption of PCMs to soil, their dissipation and leaching in soil, and their uptake by plants. Materials and Methods: In the screening study, samples of activated sewage sludge were taken both in summer and in winter at 21 treatment plants. In order to get an overview of the contamination situation, sampling covered different types of treatment plants (in rural, urban, industrial areas). Analytical methods for the determination of HHCB, AHTN, ADBI, ATTN, AHDI and ATII in the sludge samples were developed and applied. Results: The analytical screening of PCMs showed their presence in activated and dried sewage sludge samples. HHCB and AHTN represented about 95% of the PCMs investigated. Their concentrations in the activated sludge samples varied between 2.9 and 10.4 mg/kg dry mass (dm) and 1.1 to 4.2 mg/kg dm, respectively. Although different types of sewage treatment plants were investigated, similar PCM levels were found, showing the widespread input of these compounds into domestic waste water. Discussion: PCM concentrations in activated sludge varied widely. The variation drops substantially when concentrations are related to the varying dry mass. In dehydrated sludge, PCM concentrations were up to 24 mg/kg dm for HHCB and up to 6.9 mg/kg dm for AHTN. These high values are comparable to those obtained in other investigations analysing PCMs. If the degradation of organic mass during anaerobic decomposition is included in the evaluation, the figures obtained are comparable to those for activated sludge. Elimination in sewage sludge was higher in summer than in winter. Therefore, the contamination of the sludges in winter reached higher levels compared to the summer. Conclusions: The results show that PCMs are widespread contaminants in sewage sludge. Recommendations and Perspectives: PCM should be considered in a risk assessment as potential contaminants of sewage sludge destined for agricultural use. Due to the high PCM levels in sewage sludge, further investigations into the degradation and elimination behaviour in sewage sludge have to be carried out, including that involving PCM metabolites such as lactone derivatives.     

几种经济植物UFGT基因的生物信息学分析

本文根据在GenBank中已登录的葡萄、玉米、水稻、草莓、拟南芥和苹果等植物的类黄酮-3-O-葡萄糖基转移酶基因的核苷酸序列和氨基酸序列,应用生物信息学软件预测了其理化性质、疏水性/亲水性、导肽、跨膜结构、卷曲螺旋结构、二级结构、功能结构域及高级结构,并构建了类黄酮-3-O-葡萄糖基转移酶蛋白家族的系统进化树。结果表明这几种植物的UFGT基因核苷酸序列除葡萄存在2个外显子外,其它植物均存在1个外显子。含量最丰富的氨基酸是Leu、Ala、Gly、Val和Ser等,除葡萄、苹果UFGT属于不稳定类蛋白外,其余均属于稳定类蛋白。进一步研究分析表明,这几种植物UFGT蛋白存在明显的疏水区和亲水区、信号肽、跨膜结构以及卷曲螺旋。二级结构组成上比例相似,并且都由α-螺旋、延伸链和无规则卷曲所组成。它们都存在UDPGT、COG1819和MGT等保守域。除了拟南芥外,其它几种植物都能够通过同源建模建立UFGT蛋白的三维结构。进化分析表明,把它们的UFGT基因分成5个类群,其中3个大类群,另外陆地棉和野芭蕉的UFGT基因分别单独成一类。本工作将为深入研究该蛋白在植物花、果实和叶片等器官颜色变化中发挥的功能,开展生物大分子结构模拟以及药物设计提供抛砖引玉的作用。     

几种植物去除污染水体中养分效果研究

对城市尾水和人工模拟富营养化水体进行了静态培养试验.通过比较不同植物对城市尾水中氮、磷去除效果,以及它们在不同磷浓度条件下对不同形态氮素去除效果研究,目的在于筛选出适合治理富养分污染水体的植物品种.研究结果表明,空心菜(Ipomiea aquatica)、酸模(Rumex acetosa)、莎草(Cyperus glomeratus)3种植物都能很好地吸收尾水中的营养物质,且生长状况良好.经3种植物处理的城市尾水,其氮、磷浓度随水培时间的增加而降低.莎草、酸模对污水中TN的去除率达90%以上,其中莎草最高,达93.4%;空心菜对全磷的去除率最高达76.9%.NH_4~+-N在处理前期变化显著,且莎草的净化效果最好达94.4%;污水中NO_3~--N含量随着水培时间的增加而逐渐下降,但在试验后期NO_3~--N又有所增加.酸模去除NO_3~--N效果最好,达65.4%.另外3种植物对NH4+-N和NO_3~--N都具有一定的吸收作用,并且优先吸收NH_4~+-N.且从对于NH_4~+-N和NO_3~--N净化效果看,莎草>酸模>空心菜.     

Arbuscular Mycorrhizal Mediated Nutrition in Plants

ABSTRACT

Arbuscular mycorrhizae (AM) are the symbiotic fungi that predominate in the roots and soils of agricultural crop plants. The most recognized beneficial effect of these fungi is to enhance host plant uptake of relatively immobile nutrients, in particular phosphorus (P), and several micronutrients. The AM fungi absorb inorganic P either from the soluble P pools in the soil, or from insoluble forms such as rock phosphates as well as from insoluble organic sources. Recent studies show that mycorrhizal fungi would have access to rock phosphate through localized alterations of pH and/or by the production of organic acid anions that may act as chelating agents. The AM colonization also improves plant N nutrition. Generally mycorrhizal symbiosis more influences on nitrogen (N) uptake and translocation if ammonium (NH₄ ⁺) rather than nitrate (NO₃ ^?) is the nitrogen source. However, under drought stress the role of mycorrhizae in NO₃ ^? transport to the root surface may be significant as the NO₃ ^? mobility is severely restricted due to its low concentration and diffusion rate under such circumstances. However, as yet little is known about the mechanism of N uptake by the AM fungi. Uptake of micronutrients is also influenced by mycorrhizal colonization.     

不同植物对铅锌矿废弃地矿渣抗侵蚀性的影响

以废弃铅锌矿矿渣为同一基质,选择苗期光皮桦(Betulalum in iferaH.Winkl)、醉鱼草(Buddle jalind leyanaFort.)、芦竹Arundo donaxLinn.)及五节芒〔Miscanthus floridulus(Lab.)Warb.exSchumet Laut〕进行露天盆栽试验,并以生长200d后的4种植物根系及矿渣为研究对象,分析比较了4种植物的根系特征及其对矿渣紧实度、抗冲抗蚀性的影响。结果显示,4种植物的地下生物量大小为芦竹 > 醉鱼草 > 五节芒 > 苗期光皮桦,并且芦竹的根系总量明显大于其他3种植物;4种植物对矿渣的抗蚀性和抗冲性均有明显增强效应,芦竹对矿渣抗冲抗蚀性的增强效果最明显,其中芦竹对矿渣抗蚀增强系数达0.98,对矿渣抗冲性增强值为26.63。矿渣受侵蚀减缓率与植物根系生物量成显著正相关关系。     

红枣挥发性物质在烘干过程中的变化研究

新鲜成熟的团枣在25～75℃逐渐烘干，当温度在4 h升高到50℃后，控制升温速率为每4 h升高5℃，直到75℃。取鲜枣100 g及从50℃开始每隔5℃取样100 g，去核、切碎，分别用95%乙醇浸泡，蒸去乙醇得膏，然后用除去过氧化物的乙醚萃取，醚液用无水硫酸钠干燥，低温下蒸发除去乙醚后得到挥发性物质，再用气相色谱—质谱联用仪测定了上述样品的挥发性化学成分。结果表明，新鲜成熟的团枣的挥发性成分主要为13种酯类，以棕榈烯酸乙酯、肉豆蔻烯酸乙酯、亚油酸乙酯、棕榈酸乙酯、油酸乙酯、月桂酸乙酯、肉豆蔻酸乙酯等的含量较高,且其含量随着温度的升高和时间的延长而逐渐略有减少；5-羟甲基-2-呋喃甲醛和5-羟基-5，6-二氢-麦芽酚在55℃以上检出，2-呋喃甲醛在65℃以上检出，随着烘干温度逐步升高和时间增长其残留含量逐渐增高；65℃时干枣的品质最好，烘干红枣的最高温度不宜超过70℃。     

哈尔滨市不同绿地植物群落重金属分析与种植对策

采用野外调查与室内实验分析相结合的方法,以哈尔滨市街道广场绿地、单位附属绿地、苗圃生产绿地的“乔灌草密林、乔灌草疏林、灌木密林”植物群落为研究对象,综合评价不同植物群落土壤的重金属Zn、Cu、Pb含量与污染程度,对比分析不同植物群落的重金属修复效应及树木含水量、全氮、全磷含量与土壤重金属富集的相关性.结果表明:土壤重金属修复能力为乔灌草密林＞灌木密林＞乔灌草疏林;植物根系重金属富集能力最强,其中小根对锌、铜富集能力较强,大根、中根对铅富集能力较强;树种富集重金属能力显著不同,梓树、黄檗对铜富集能力较强,铺地柏、红皮云杉、小叶丁香对铅富集能力较强,紫丁香、胡桃楸对锌富集能力较强;树木富集铜和锌的能力与其叶片含水量、叶片全磷含量密切相关.为了有效修复土壤重金属污染,提出了优先选用耐重金属植物、努力提高乔灌木小根数量、科学营造乔灌草复层群落等种植对策.     

湿地植物对农村生活污水中氮磷的净化作用

[目的] 探讨水生植物修复技术对农村生活污水的治理效果,为乡村生态综合治理提供思路借鉴和参考资料。[方法] 通过模拟室内控制试验的方法,选取不同生态型的6种湿地植物为研究对象,分析植株生物量、去除率、植物积累量、底泥吸附量等多项指标变化,研究不同水生植物及其组合对污水中氮磷的净化效果差异以及水生植物系统的脱氮除磷特征。[结果] 无论单一种植组或混合种植组,水生植物系统对污水中TN,NH₄⁺-N,TP均有较好的净化效果,平均去除率分别达到96.6%,93.2%和95.9%,显著高于对照组。单一种植的再力花长势最好,鸢尾地上和地下部分生物量的比值最大,混合种植的美人蕉以及单一种植的梭鱼草相对生长速率最低。挺水植物对氮素的吸收作用更好,苦草对磷的吸收效果更好。植物吸收氮、磷占系统总去除量的比例在6.9%~18.3%和4.1%~13.6%之间,底泥吸附氮、磷占总去除量的比例在14.0%~31.5%和26.3%~68.4%之间。微生物及其他植物的间接作用是植物系统脱氮除磷的主要影响因素。[结论] 再力花、鸢尾及苦草的镶嵌组合是在淮北平原区湿地植物种植的理想选择。对水生植物的组合方式、数量、时间等进行优化配置,能够有效用于农村生活污水的净化。     

不同类型脱水素在植物低温胁迫应答中的作用

低温是影响植物生长发育和作物产量的非生物胁迫因子之一。植物在长期的进化过程中,通过调节自身的生理及分子变化,形成了对低温胁迫的适应能力。脱水素是一类晚期胚胎丰富蛋白,可保护植物细胞内蛋白质和膜结构等不被低温破坏。不同植物中脱水素的过量表达能够提高植物的低温抗性,植物脱水素的表达和蛋白质的积累与植物耐低温能力密切相关。本文对SKn、Kn、YnSKn、KnS和Yn Kn型脱水素在植物抵御低温胁迫过程中的作用进行综述,旨在为进一步利用脱水素进行植物抗低温分子育种研究提供参考。