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  农业环境科学学报  2017, Vol. 36 Issue (8): 1453-1461

文章信息

杨姝, 李元, 毕玉芬, 祖艳群, 何永美, 贾乐
YANG Shu, LI Yuan, BI Yu-fen, ZU Yan-qun, HE Yong-mei, JIA Le
紫花苜蓿对Cd胁迫的响应及品种差异研究进展
Response and intraspecific differences of alfalfa to cadmium (Cd) stress
农业环境科学学报, 2017, 36(8): 1453-1461
Journal of Agro-Environment Science, 2017, 36(8): 1453-1461
http://dx.doi.org/10.11654/jaes.2017-0341

文章历史

收稿日期: 2017-03-12
紫花苜蓿对Cd胁迫的响应及品种差异研究进展
杨姝, 李元, 毕玉芬, 祖艳群, 何永美, 贾乐     
云南农业大学资源与环境学院, 昆明 650201
摘要: 为利用紫花苜蓿对Cd污染土壤进行修复和综合利用提供理论基础。综述了紫花苜蓿对Cd胁迫的响应,包括:紫花苜蓿的生长对Cd的响应存在"低促高抑"现象;紫花苜蓿对Cd吸收的可能途径包括根表皮质膜的H+交换、Ca2+和Mg2+阳离子通道,根际环境和Cd元素在土壤中的有效态等因素会影响紫花苜蓿对Cd的吸收;在Cd由根部向地上部转运的过程中,随着土壤Cd含量的增加,更多的Cd被累积在紫花苜蓿的根部;紫花苜蓿应对土壤Cd胁迫的调控机理包括信号分子调控、抗氧化系统调控、生物巯基化合物对Cd的螯合、调节Cd的亚细胞分布和耐Cd基因的表达等多个方面。总结了紫花苜蓿对Cd胁迫响应的品种差异,主要表现在:种子萌发和幼苗生长;根瘤生长、植株形态和生物量;生理指标;对Cd的吸收与累积等方面。今后的研究工作可重点关注品种差异评判标准的建立、差异显著品种的系统筛选、在分子水平上的响应机理及品种差异机理的分析等方面。
关键词: 紫花苜蓿     Cd胁迫     响应     品种差异     机理    
Response and intraspecific differences of alfalfa to cadmium (Cd) stress
YANG Shu, LI Yuan, BI Yu-fen, ZU Yan-qun, HE Yong-mei, JIA Le     
College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China
Project supported: The Soil Pollution Comprehensive Treatment Major Projects of Ministry of Environmental Protection(YNBY2016-002); NSFC-Yunnan Joint Fund Project(U1202236)
Abstract: The responses of alfalfa(Medicago sativa L.) to Cd stress are reviewed in this paper, as follows:The response of alfalfa growth to Cd stress presented trends of promotion at low concentrations and inhibition at high concentrations. The stress damage caused by Cd on alfalfa was alleviated by physiological responses including antioxidative system activation changes in biological membrane permeability, photosynthesis regulation, and osmotic regulation. Possible Cd adsorption strategies included H+ exchange in the plasma membrane of the root epidermis and Ca2+ and Mg2+ cation channels in their roots. Cd uptake in alfalfa roots was affected by the rhizosphere environment and bioavailability of Cd in soil. When Cd transported from root to shoots, it accumulated in the roots of alfalfa with an increase of Cd content in the soil. Of alfalfa plants regulated their response to Cd stress with mechanisms included signal molecular regulation, antioxidant system regulation, combining Cd with thiols, subcellular distribution of Cd, and upregulation of Cd-resistant gene expression. H2S, NO, and CO were considered possible signal molecules, while upregulation of heme oxygenase-1(HO-1) transcription and increased heme oxygenase(HO) activity could be the key to activating the antioxidant system. Intraspecific differences of alfalfa in response to Cd stress are also reviewed in this paper, including the following:Seed germination and seedling growth of alfalfa showed remarkable differences among cultivars under Cd stress, and the maximum Cd tolerance value of various alfalfa cultivars was more than nine times greater than that of the minimum value. Under Cd stress, there were remarkable differences in nodule growth, plant morphology, and biomass between alfalfa cultivars, and the root length was considered an important indicator in evaluating intraspecific differences. The changes in physiological indicators, such as glutathione reductase(GR) and ascorbate peroxidases(APXs) activity, GSH, hGSH, chlorophyll, proline, and MDA concentrations, and the leakage rate of electrolytes were very different among various alfalfa cultivars under the same level of Cd stress. Absorption and accumulation of Cd in alfalfa also had intraspecific differences. Generally, Cd stress in alfalfa should be studied further in the future to establish criteria to judge intraspecific differences, studying significant differences in system selection, analysis at the molecular level of stress response mechanisms, and intraspecific differences to Cd stress as this would help provide theoretical and practical bases for using alfalfa for the restoration and utilization of Cd-contaminated soil.
Key words: Medicago sativa L.     cadmium stress     stress response     intraspecific differences     mechanism    

由于对农业生产和食品安全的不利影响,重金属污染已在世界范围内引起广泛关注[1]。Cd是植物非必需元素,易从土壤向植物迁移[2],并可能通过食物链在人体内蓄积[3],被美国毒物管理委员会(ATSDR)列为第六位危害人体健康的有毒物质[4]。目前我国土壤Cd污染形势严峻,其点位超标率达7.0%,在Cd、Hg、As、Cu、Pb、Cr、Zn、Ni 8种无机污染物中位列第一[5],对此,可行的应对措施包括利用超富集植物进行植物修复和种植低累积植物等[6-7]

紫花苜蓿(Medicago sativa L.)是一种优良牧草,在世界各国广泛种植,有“牧草之王”的美誉。紫花苜蓿对重金属有一定的耐性[8]和累积能力[9-10],在植物提取方面有较好的特性[11-12]。在Cd、Zn、Cu、Pb几种金属中,紫花苜蓿对Cd的吸收系数最大[13],对Cd污染土壤具有一定的修复能力[14]。不同的紫花苜蓿品种对Cd胁迫的响应存在显著差异[15-16],可以作为Cd污染土壤治理和综合利用的备选植物,相关研究具有重要的理论和实践意义。

1 紫花苜蓿对Cd胁迫的响应 1.1 紫花苜蓿对Cd胁迫响应的特征

紫花苜蓿的生长对Cd的响应存在“低促高抑”现象[17-18],当Cd浓度超过一定阈值后,其种子萌发[19-20]、根瘤生长[21-22]、生物量[23]、植株形态[24]等均会受到不同程度抑制,且有侧根产生的情况出现[25]。紫花苜蓿主要通过抗氧化系统的激活[26]、生物膜透性的改变[27]、光合作用调节[28]和渗透调节[29]等措施来应对Cd的逆境胁迫,其体内超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性会随着Cd胁迫浓度的升高呈现出程度不一的升高-降低变化[30],Cd胁迫也抑制了其体内谷胱甘肽还原酶(GR)的活性并导致谷胱甘肽(GSH)被消耗[31];此外,叶绿素[32]、丙二醛(MDA)、脯氨酸和可溶性糖的含量以及相对电导率等指标均会受到Cd胁迫的影响[27, 29]。紫花苜蓿能吸收并累积土壤中的Cd,其Cd累积量与土壤中有效Cd的量呈显著线性关系[33],并表现出植株Cd含量高于土壤Cd含量[34]、根部Cd含量高于茎秆和叶片Cd含量[35]的Cd累积特征,在一定程度上限制了Cd由根部向地上部的转移。

1.2 紫花苜蓿对Cd的吸收和转运 1.2.1 紫花苜蓿对Cd的吸收

根系吸收是植物吸收土壤重金属的主要途径,土壤中的Cd以在根表皮质膜与H+交换、占用非选择性阳离子(Fe2+、Zn2+和Ca2+)通道和形成麦根酸螯合物等方式[36],进入植物根部表皮层内[37],再经由共质体和质外体两种途径抵达维管束并向枝叶转运[38]。紫花苜蓿根系对Cd2+的吸收存在阳离子交换过程,H+可能会影响紫花苜蓿根系对Cd2+的吸收能力,Cd2+的吸收量与Ca2+、Mg2+、Na+的释放显著相关,且这种交换主要存在于Cd2+和二价阳离子之间[39]图 1)。紫花苜蓿对Cd的吸收与根际环境、土壤中Cd的有效态及土壤对Cd的吸附等因素有关:丛枝菌根真菌(AMF)的接种会影响紫花苜蓿对Cd的吸收量[40-41],可能是由于菌丝本身对Cd的固持作用[42]及菌丝分泌物对土壤中重金属形态的改变[43]而导致的。土壤pH值对Cd的吸收也有较大影响,如施用氮肥能增加紫花苜蓿对Cd的平均吸收量和吸收效率[44],可能是由于氮肥释放的NH4+导致土壤酸化增加了土壤中Cd的有效性而造成的[45],在土壤中添加柠檬酸的实验也得到了类似结果[46]。此外,高盐度会促进紫花苜蓿对Cd的吸收,其可能的机制在于金属-氯络合物的形成降低了土壤对金属的吸附,增加了植物对金属的利用率[47]

图 1 紫花苜蓿对土壤Cd胁迫的响应 Figure 1 Respons of alfalfa to Cd stress in soil
1.2.2 紫花苜蓿对Cd的转运

Cd被植物根系吸收后,经质外体途径和共质体途径的短距离运输进入根部维管束[48],再经木质部及韧皮部装载的长距离运输被转运到植株地上各部分[49]。Cd由根部向地上部的运输可能是以蒸腾作用为动力的,在此过程中,Cd可能以离子态和有机结合态的形式存在[50]。目前,多个与Cd转运有关的基因或QTL被鉴定,其中既有调控胞间Cd跨膜运输的细胞膜蛋白,也有维持胞内Cd稳态的液泡膜蛋白[51]。在紫花苜蓿对Cd的转运过程中,更多的Cd被留在木质部薄壁细胞壁的阳离子交换点并被固定在根部细胞的液泡中,使得其对Cd的转运因子(TFs)小于1[52],随着Cd处理浓度的增加,紫花苜蓿对Cd的TF值有下降的趋势,可能与ABA-诱导的气孔关闭和细胞对Cd的隔离有关[53];此外,紫花苜蓿对Cd的转运指数(Transport index=Shoot content/Total plant content×100,TI)与Cd处理浓度也呈负相关关系,说明随着处理浓度的增加,更多的Cd被留在了植株的根部[54]图 1)。值得注意的是,近期以突尼斯南部矿区土壤为盆栽土的实验发现,在所有处理条件下紫花苜蓿对Cd的TF值均超过了2[55]。这与前人的报道有较大差异,其机制尚不明确,可能与种植的土壤条件和苜蓿的品种有关。

1.3 紫花苜蓿应对Cd胁迫的调控机理 1.3.1 信号分子调控

作为一种信号分子,Cd诱导的H2S生成是紫花苜蓿Cd耐性的可能机制,从外源NaHS添加实验发现,环腺苷酸(cAMP)信号也可能参与了NaHS诱导的紫花苜蓿Cd响应过程[56]。H2S(NaHS)和NO(Sodium Nitroprusside,SNP)的复合预处理可降低Cd对紫花苜蓿的毒性,并在使用了特定的NO清除剂cPTIOP后被逆转[57],表明NO与NaHS诱导的Cd解毒过程有关,同时也说明了NO和H2S之间存在一个交叉对话,以增强紫花苜蓿对非生物胁迫的耐性(图 1)。此外,CO也是一种可能的信号分子,其可调节紫花苜蓿体内谷胱甘肽(GSH)的新陈代谢,通过此代谢来缓解Cd导致的氧化损伤[58]

1.3.2 抗氧化系统调控

在Cd胁迫下,10%富氢水(Hydrogen-Rich Water,HRW)的添加能显著降低Cd引发的硫代巴比妥酸反应物含量,同时抑制Cd毒性症状的出现。这些响应与总的或典型的抗氧化同工酶活性及其对应转录的显著增加有关,这证明了抗氧化系统的激活是紫花苜蓿Cd耐性的关键环节[59]。此外,CO合成酶血红素加氧酶(HO)活性及其HO-1的转录水平在紫花苜蓿抵御氧化损伤的过程中起着关键作用。Cd胁迫下,发现紫花苜蓿籽苗根部Cd诱导的HO-1基因表达在转录水平的上调与GSH的消耗相关,并最终导致了瞬间抗氧化能力的增强[60];外源添加抗坏血酸(AsA)能强化Cd引发的紫花苜蓿HO-1的转录上调和HO的活性,此反应对锌原卟啉IX(ZnPP IX)敏感且CO处理后可逆[61],说明AsA引发的细胞保护作用可能是经由抗氧化系统和低Cd累积诱导的HO-1相关模式实现的;用能诱导MsHO1基因表达的HO-1诱导剂氯高铁血红素(Haemin)或水杨酸(SA)预处理,可显著降低Cd对紫花苜蓿的生长抑制和植株Cd累积[62],由此推测HO-1还可能参与了水杨酸诱导的减轻Cd胁迫在紫花苜蓿籽苗根部造成的氧化损伤的过程。此外,CDH(β-cyclodextrin-hemin)和血红素加氧酶(Hemin)预处理获得的HO-1上调可以抵御由Cd胁迫导致的紫花苜蓿籽苗根部的氧化损伤[63],表明由CDH调控的HO-1诱导也是抗氧化反应的关键环节之一(图 1)。

1.3.3 与生物巯基化合物(Biothiols)的结合

体内Biothiols与Cd的结合是紫花苜蓿缓解Cd毒的重要方式之一(图 1)。在Cd胁迫下,紫花苜蓿体内的Biothiols含量急剧增加,并伴随着γ-谷氨酰半胱氨酸合成酶(γ-GCS)基因的急剧上调。可以推测Cd是有效的S代谢感应器,增加硫酸盐的吸收率并促进其同化途径,植物在地上部合成GSH/hGSH,然后将这些生物巯基化合物运送到根部,在根部转化为植物螯合肽(PCs/hPCs),与根部的Cd形成络合物,以减低Cd对植物的毒性[64]

1.3.4 亚细胞分布的调节

接种AMF后紫花苜蓿的Cd耐性增强。分析发现,这种能力是通过降低植株对Cd的TF值和植株中结合态Cd的比例[65],并使得细胞壁中的Cd增加而细胞器和细胞膜中的Cd降低[66]而获得的,可见调节体内Cd的亚细胞分布也是紫花苜蓿应对土壤Cd胁迫的调控方式之一(图 1)。

1.3.5 耐Cd基因的表达

在250 μmol·L-1的Cd胁迫6 h后,使用差别显示逆转录聚合酶链反应的退火控制引物(Annealing Control Primers,ACP)技术发现,紫花苜蓿中的一个差异表达基因(Differentially Expressed Genes,DEGs)出现上调,同时5个新基因被鉴定,此上调的DEGs可能在紫花苜蓿的Cd耐性方面发挥一定的作用[67]。从两个耐性品种“野苜蓿”(Medicago sativa L.cv. Ye)和“陇中苜蓿”(Medicago sativa L.cv. Longzhong)叶片中获得的源于差异表达金属硫蛋白基因的候选片段被克隆,其基因序列和推导出的蛋白质序列显示MsMT2aMsMT2b与在豆科植物中获得的高度相似,DDRT-PCR分析表明,MsMT2a在“野苜蓿”和“陇中苜蓿”中均有表达,但MsMT2b仅在Cd处理条件下表达,推测出MsMT2a在紫花苜蓿叶片中是普遍表达的,而MsMT2b是由Cd诱导表达的[16]

2 紫花苜蓿对Cd胁迫响应的品种差异 2.1 种子萌发和幼苗生长对Cd胁迫响应的品种差异

不同品种的紫花苜蓿,其种子萌发与幼苗生长对Cd胁迫的响应存在显著差异,具体可表现为对Cd耐受浓度的较大差别,如表 1所示:品种“新牧1号”[19]Medicago sativa L.cv.Xinmu No.1)和“中牧1号”[68]Medicago sativa L.cv. Zhongmu No.1),其种子萌发及幼苗生长在Cd处理浓度分别为6 mg·L-1和15 mg·kg-1时即受到严重抑制,相对较为敏感;而品种“甘农3号”[20]Medicago sativa L.cv.Gannong 3)、“阿尔冈金”[18]Medicago sativa L.cv. Algonuin)和“盛世”[69]Medicago sativa L.cv. Shengshi)的Cd耐受浓度则可分别达到56、40 mg·L-1和30 mg·kg-1,同时发现“阿尔冈金”的发芽率、发芽势、发芽指数和活力指数等指标在CdCl2≤20 mg·L-1时得到了显著提高,显示出一定的“低促高抑”现象[18]

2.2 形态和生物量对Cd胁迫响应的品种差异

根长是紫花苜蓿对Cd响应的重要形态指标之一。在Cd处理浓度为25 mg·L-1的水培实验中,36个受试品种根长减少范围为3.7%~88.7%,可见其品种差异显著,据此为主要衡量指标,“野苜蓿”和“陇中”被确定为耐Cd品种[16];株高、下胚轴长度、根质量、地上部质量等指标也被用于衡量不同紫花苜蓿品种对Cd胁迫的响应差异(表 1)。在Cd处理浓度为50 mg·kg-1时,品种“多叶”(Medicago sativa L.cv. Duoye)的Cd耐性被认为强于品种“准格尔”(Medicago sativa L.cv.Jungar)[24];Cd处理浓度在0~5 mg·L-1范围时,品种“阿尔冈金”的Cd耐性被认为强于品种“新疆大叶”(Medicago sativa L. cv. Xinjiangdaye)[71]

表 1 紫花苜蓿对Cd胁迫响应的品种差异 Table 1 Intraspecific difference of alfalfa in response to Cd stress
2.3 根瘤对Cd胁迫响应的品种差异

豆科植物的根瘤是根瘤菌-植物共生体系生物固氮的场所,具有独特的结构,在形态学和生理学上与其他植物器官有较大区别[72]。不同品种的紫花苜蓿,其根瘤数、根瘤重、根瘤菌活性和固氮酶活性等指标对Cd的响应均表现出一定差异,如品种“盛世”的根瘤固氮对Cd胁迫较为敏感,其固氮酶活性在Cd添加量达5 mg·kg-1时即受到严重抑制[73],而在相同处理浓度下,品种“多叶”和“准格尔”根瘤对Cd的响应则表现为轻微的促进作用;当Cd处理浓度进一步增加后,“多叶”和“准格尔”的根瘤鲜重和根瘤数才会显著下降,且相同Cd浓度下“准格尔”的降幅大于“多叶”[74]。品种“Gabès”(Medicago sativa L. cv. Gabès)及其中华根瘤菌共生体系可在突尼斯(Tunisia)矿区含Cd污染的土壤上正常生长并有效结瘤,从中分离到的根瘤菌菌株可耐受33.6 mg·L-1的Cd胁迫,其中菌株S532能吸收比菌株S112更少量的金属而表现出较强的Cd耐性[75]

2.4 生理指标对Cd胁迫响应的品种差异

抗氧化系统的响应是紫花苜蓿应对Cd胁迫的重要手段之一,在不同的紫花苜蓿品种间存在差异。3.36 mg·L-1的Cd处理严重抑制了品种“Aragon”(Medicago sativa L.var. Aragon)的GR的活性(抑制率>50%),并增加了其APXs的活性[31],同时增加GSH和hGSH的含量并促进了细胞活性氧和细胞外H2O2的产生和形成[64, 76];22.4 mg·L-1的Cd处理干扰了品种“Victoria”(Medicago sativa L. Victoria)籽苗根部GSH的内平衡和H2S的产生,同时两种H2S合成酶(LCD和DCD)的活性受到抑制[56]

光合作用对Cd胁迫的响应也与紫花苜蓿的品种有关。在施Cd量为5 mg·kg-1时,品种“WL-323HQ”(Medicago sativa L.cv. WL-323HQ)的叶绿素含量(总叶绿素、叶绿素a和叶绿素b)高于无Cd处理,当Cd浓度进一步增加时上述指标受到抑制[30];1.0 mg·L-1以下的Cd处理增加了品种“肇东”(Medicago sativa L. cv. Zhaodong)的叶绿素含量,更高浓度则对其产生抑制,当处理浓度达10 mg·L-1时,“肇东”的叶绿素含量显著下降(P < 0.05)[32]。与之类似,品种“Sargodha 2002”(Medicago sativa L. var. Sargodha 2002)的光合作用在Cd处理浓度为10 mg·L-1时受到显著抑制(P < 0.05)[28];使用浓度为25 mg·L-1的CdCl2处理“野苜蓿”和“陇中苜蓿”,发现其幼苗第五片叶的Fv/Fm值降低程度并不显著,表明“野苜蓿”和“陇中苜蓿”光合系统对Cd的耐受值可达25 mg·L-1,耐Cd性相对较强[15]

紫花苜蓿的渗透调节对Cd胁迫的响应也存在品种差异。在Cd处理浓度为1 mg·L-1时,品种“阿尔冈金”的脯氨酸含量小于“新疆大叶”,而MDA含量和电解质泄漏率则大于“新疆大叶”,一定程度说明“阿尔冈金”的耐Cd性要强于“新疆大叶”[71];在重度Cd胁迫时(>30 mg·L-1),品种“肇东”、“准格尔”和“多叶8925”的电导率出现显著差异,顺序为“准格尔”>“肇东”>“多叶8925”,说明品种“多叶”膜稳定性较强,从渗透调节的角度而言说明其具有相对较强的耐Cd性[77]

2.5 对Cd吸收与累积的品种差异

品种“Col”(Medicago sativa L var. Col)有较强的Cd吸收累积能力,生长21 d即可吸收水中80%~85%的Cd,在处理浓度为50 mg·L-1时,其地上部和地下部的吸收量分别可达1920、12 360 mg·kg-1(DW)[54];品种“新疆大叶”在Cd处理浓度为100 mg·kg-1时,其地上部和地下部的Cd含量分别为16.01、84.21 mg·kg-1(DW)[29],与前者存在较大差异;品种“阿尔冈金”在土壤Cd含量分别低于0.55、9.37 mg·kg-1时,其分枝期和开花期的干草Cd含量不会超过饲料卫生安全限定标准[23];品种“准格尔”各部分Cd累积量的顺序为细根>地上部>粗根,且细根Cd含量与地上部Cd含量呈显著正相关,当Cd处理浓度为25 mg·kg-1时,地上部Cd累积量达到了最高的7.715 μg·株-1[25]。可见,不同品种紫花苜蓿吸收和累积Cd的能力存在较大差异(表 1)。通过筛选可获得不同特性品种,高Cd累积品种可作为潜在的Cd污染修复植物用于土壤的植物修复,低Cd累积品种可作为优质饲草在Cd污染土壤上种植,充分利用土地的同时也降低了Cd经由食物链进入人体的风险。

3 小结和展望

紫花苜蓿对Cd的响应涉及其生长过程的各个环节并存在显著的品种差异,体现在发芽、生长、形态、生理、植株对Cd的吸收和累积等多个方面。紫花苜蓿通过信号分子的调控、抗氧化系统的激活、对Cd的螯合、区室化Cd和耐Cd基因表达的上调等手段来抵御和消除Cd的毒害,在这些环节中,H2S、NO和CO等被认为是可能的信号分子,HO-1转录的上调和HO活性的增强可能是激活抗氧化系统的关键。

随着土壤Cd污染问题的日趋突出,使用紫花苜蓿对Cd污染土壤进行植物修复成为一种可能的有效途径。目前的相关工作多集中于特定紫花苜蓿品种对Cd的响应特征研究方面,也从机理上做了一些探讨,而对一系列品种的Cd响应差异性筛选、Cd响应和品种差异的分子机理等方面的研究相对较少,以哪些指标作为品种差异的评判标准则尚无定论。后续的研究工作可重点围绕上述几个方面深入开展,以期为紫花苜蓿用于Cd污染土壤的修复和综合利用等提供理论基础和技术支持。

参考文献
[1]
黄益宗, 郝晓伟, 雷鸣, 等. 重金属污染土壤修复技术及其修复实践[J]. 农业环境科学学报, 2013, 32(3): 409-417.
HUANG Yi-zong, HAO Xiao-wei, LEI Ming, et al. The remediation technology and remediation practice of heavy metals-contaminated soil[J]. Journal of Agro-Environment Science, 2013, 32(3): 409-417.
[2]
Murakami M, Ae N, Ishikawa S, et al. Phytoextraction by a high-Cd-accumulating rice:Reduction of Cd content of soybean seeds[J]. Environ Sci Technol, 2008, 42(16): 6167-6172. DOI:10.1021/es8001597
[3]
Järup L, Åkesson A. Current status of cadmium as an environmental health problem[J]. Toxicology and Applied Pharmacology, 2009, 238(3): 201-208. DOI:10.1016/j.taap.2009.04.020
[4]
谢黎虹, 许梓荣. 重金属镉对动物及人类的毒性研究进展[J]. 浙江农业学报, 2003, 15(6): 52-57.
XIE Li-hong, XU Zi-rong. The toxicity of heavy metal cadmium to animals and humans[J]. Acta Agriculturae Zhejiangensis, 2003, 15(6): 52-57.
[5]
庄国泰. 我国土壤污染现状与防控策略[J]. 中国科学院院刊, 2015, 30(4): 477-483.
ZHUANG Guo-tai. Current situation of national soil pollution and strategies on prevention and control[J]. Bulletin of Chinese Academy of Sciences, 2015, 30(4): 477-483.
[6]
刘维涛, 周启星. 重金属污染预防品种的筛选与培育[J]. 生态环境学报, 2010, 19(6): 1452-1458.
LIU Wei-tao, ZHOU Qi-xing. Selection and breeding of heavy metal pollution-safe cultivars[J]. Ecology and Environmental Sciences, 2010, 19(6): 1452-1458.
[7]
Liu W T, Zhou Q X, An J, et al. Variations in cadmium accumulation among Chinese cabbage cultivars and screening for Cd-safe cultivars[J]. Journal of Hazardous Materials, 2010, 173(1/2/3): 737-743.
[8]
Yang J, Teng Y G, Zuo R, et al. Comparison of bioavailable vanadium in alfalfa rhizosphere soil extracted by an improved BCR procedure and EDTA, HCl, and NaNO3 single extractions in a pot experiment with V-Cd treatments[J]. Environmental Science and Pollution Research, 2015, 22(12): 8833-8842. DOI:10.1007/s11356-013-1917-1
[9]
Nouairi I, Mrabet M, Rabhi M, et al. Cu-tolerant Sinorhizobium meliloti strain is beneficial for growth, Cu accumulation, and mineral uptake of alfalfa plants grown in Cu excess[J]. Archives of Agronomy and Soil Science, 2015, 61(12): 1707-1718. DOI:10.1080/03650340.2015.1036043
[10]
Liu Z F, Ge H G, Li C, et al. Enhanced phytoextraction of heavy metals from contaminated soil by plant Co-cropping associated with PGPR[J]. Water Air and Soil Pollution, 2015, 226(3): 1-10.
[11]
Pajuelo E, Carrasco J A, Romero L C, et al. Evaluation of the metal phytoextraction potential of crop legumes. regulation of the expression of O-acetylserine(Thiol) Lyase under metal stress[J]. Plant Biology, 2007, 9(5): 672-681. DOI:10.1055/s-2007-965439
[12]
Benzarti S, Mohri S, Ono Y. Plant response to heavy metal toxicity:Comparative study between the hyperaccumulator Thlaspi caerulescens(ecotype Ganges) and nonaccumulator plants:Lettuce, radish, and alfalfa[J]. Environmental Toxicology, 2008, 23(5): 607-616. DOI:10.1002/tox.v23:5
[13]
王新, 贾永锋. 紫花苜蓿对土壤重金属富集及污染修复的潜力[J]. 土壤通报, 2009, 40(4): 932-935.
WANG Xin, JIA Yong-feng. Heavy metals accumulation and phytoremediation of alfalfa in contaminated soil[J]. Chinese Journal of Soil Science, 2009, 40(4): 932-935.
[14]
樊瑞, 冯永军, 郝桂喜, 等. 富镉基质中紫花苜蓿的生长与利用研究[J]. 草业科学, 2009, 26(10): 67-72.
FAN Rui, FENG Yong-jun, HAO Gui-xi, et al. Study on growth and utilization of alfalfa grown in Cd-rich substrate[J]. Pratacultural Science, 2009, 26(10): 67-72.
[15]
宋瑜. 紫花苜蓿(Medicago sativa L. )抗镉品种金属硫蛋白基因差异显示分析[D]. 兰州: 兰州大学, 2009.
SONG Yu. Differential display of metallothionein gene in Cd-tolerant alfalfa(Medicago sativa L.) varieties[D]. Lanzhou:Lanzhou University, 2009. http://cdmd.cnki.com.cn/Article/CDMD-10730-2009190961.htm
[16]
Wang X, Song Y, Ma Y, et al. Screening of Cd tolerant genotypes and isolation of metallothionein genes in alfalfa(Medicago sativa L.)[J]. Environmental Pollution, 2011, 159(12): 3627-3633. DOI:10.1016/j.envpol.2011.08.001
[17]
白音达来, 包额尔顿嘎. 不同浓度硝酸镉对紫花苜蓿种子萌发及幼苗生长的影响[J]. 农业科技通讯, 2013(6): 128-130.
BAI In-da-lai, BAO Er-dun-ga. Effects of different concentrations cadmium nitrate on seed germination and seedling growth of alfalfa[J]. Bulletin of Agricultural Science and Technology, 2013(6): 128-130.
[18]
王文斌, 金樑, 李晶, 等. 不同pH条件下CdCl2对紫花苜蓿种子萌发的胁迫效应[J]. 环境科学研究, 2013, 26(10): 1095-1102.
WANG Wen-bin, JIN Liang, LI Jing, et al. Effects of CdCl2 stress under different pH to seed germination in alfalfa[J]. Research of Environmental Sciences, 2013, 26(10): 1095-1102.
[19]
张良绘, 朱俊瑾, 朱新萍, 等. Cd2+与NaCl胁迫对紫花苜蓿种子萌发的影响[J]. 新疆农业大学学报, 2015, 38(1): 51-55.
ZHANG Liang-hui, ZHU Jun-jin, ZHU Xin-ping, et al. Effects of Cd2+ and NaCl stress on seed germination of alfalfa[J]. Journal of Xinjiang Agricultural University, 2015, 38(1): 51-55.
[20]
尹国丽, 师尚礼, 寇江涛, 等. Cd胁迫对紫花苜蓿种子发芽及幼苗生理生化特性的影响[J]. 西北植物学报, 2013, 33(8): 1638-1644.
YIN Guo-li, SHI Shang-li, KOU Jiang-tao, et al. Seed germination and physiological and biochemical characteristics of alfalfa under cadmium stress[J]. Acta Botanica Boreali-Occidentalia Sinica, 2013, 33(8): 1638-1644.
[21]
Antipchuk A F, Rangelova V N, Tantsiurenko E V. Species and strain sensitivity of diasotrophs to heavy metals[J]. Mikrobiolohichnyi Zhurnal, 2002, 64(3): 44-51.
[22]
Neumann H, Werner D. Gene expression of Medicago sativa inoculated with Sinorhizobium meliloti as modulated by the xenobiotics cadmium and fluoranthene[J]. Zeitschrift fur Naturforschung C, Journal of Biosciences, 2000, 55(3/4): 222-232.
[23]
李新博, 谢建治, 李博文, 等. 镉对紫花苜蓿不同生长期生物量的影响及饲用安全评价[J]. 草业学报, 2009, 18(5): 266-269.
LI Xin-bo, XIE Jian-zhi, LI Bo-wen, et al. A study on cadmium content of alfalfa at different growth stages and an evaluation of forage feed security[J]. Acta Prataculturae Sinica, 2009, 18(5): 266-269. DOI:10.11686/cyxb20090535
[24]
徐苏凌, 邢承华, 方勇. 镉胁迫对紫花苜蓿生长及植株镉含量的影响[J]. 广东微量元素科学, 2008, 15(3): 23-26.
XU Su-ling, XING Cheng-hua, FANG Yong. The effect of cadmium stress on growth and Cd content of alfalfa[J]. Guangdong Trace Elements Science, 2008, 15(3): 23-26.
[25]
李希铭, 宋桂龙. 镉胁迫对紫花苜蓿镉吸收特征及根系形态影响[J]. 草业学报, 2016, 25(2): 178-186.
LI Xi-ming, SONG Gui-long. Cadmium uptake and root morphological changes in Medicago sativa under cadmium stress[J]. Acta Prataculturae Sinica, 2016, 25(2): 178-186. DOI:10.11686/cyxb2015401
[26]
苏向楠. NO对Cd胁迫下紫花苜蓿幼苗氧化损伤与Cd积累的调控作用及其机制[D]. 兰州: 兰州交通大学, 2015.
SU Xiang-nan. Regulatory role and mechanism of NO on oxidative damage and the accumulation of Cd in alfalfa seedlings under the Cd stress[D]. Lanzhou:Lanzhou Jiaotong University, 2015. http://cdmd.cnki.com.cn/Article/CDMD-10732-1015448213.htm
[27]
丁晓辉, 任丽萍, 张春荣, 等. Cd2+胁迫对紫花苜蓿叶绿素和可溶性糖含量的影响[J]. 华北农学报, 2007, 22(增刊): 64-66.
DING Xiao-hui, REN Li-ping, ZHANG Chun-rong, et al. Effect of Cd2+ stress on the content of chlorophyll and soluble sugar of alfalfa[J]. Acta Agriculturae Boreali-Sinica, 2007, 22(Suppl 1): 64-66.
[28]
Mahmood S, Malik S A, Tabassum A, et al. Biometric and biochemical attributes of alfalfa seedlings as indicators of stress induced by excessive cadmium[J]. Journal of Soil Science and Plant Nutrition, 2014, 14(3): 546-553.
[29]
孙宁骁, 宋桂龙. 紫花苜蓿对镉胁迫的生理响应及积累特性[J]. 草业科学, 2015, 32(4): 581-585.
SUN Ning-xiao, SONG Gui-long. Physiological response of Medicago sativa to cadmium stress and accumulation property[J]. Pratacultural Science, 2015, 32(4): 581-585.
[30]
徐苏凌, 方勇, 邢承华. 酸雨和Cd胁迫对紫花苜蓿生长和抗氧化酶系统的影响[J]. 浙江大学学报(农业与生命科学版), 2008, 34(4): 467-472.
XU Su-ling, FANG Yong, XING Cheng-hua. Complex effects of acid rain and cadmium on growth and antioxidase system of alfalfa[J]. Journal of Zhejiang University(Agric & Life Sci), 2008, 34(4): 467-472.
[31]
Laura Flores-Caceres M, Hattab S, Hattab S, et al. Specific mechanisms of tolerance to copper and cadmium are compromised by a limited concentration of glutathione in alfalfa plants[J]. Plant Science, 2015, 233: 165-173. DOI:10.1016/j.plantsci.2015.01.013
[32]
吴旭红, 付本丽. 不同浓度镉对苜蓿生长及抗氧化系统的影响[J]. 黑龙江大学自然科学学报, 2005, 22(3): 363-365.
WU Xu-hong, FU Ben-li. Effects of different concentrations of cadmium on growth and antioxidant system in Medicago sativa L. cv[J]. Journal of Natural Science of Heilongjiang University, 2005, 22(3): 363-365.
[33]
杨玉惠, 张春荣, 夏立江, 等. 镉锌污染对紫花苜蓿体内镉含量及品质的影响[J]. 华北农学报, 2008, 23(增刊2): 363-366.
YANG Yu-hui, ZHANG Chun-rong, XIA Li-jiang, et al. Effect of cadmium and zinc pollutions of alfalfa quality and cadmium content[J]. Acta Agriculturae Boreali-Sinica(Acta Agric Boreali Sin), 2008, 23(Suppl 2): 363-366.
[34]
Marcelo Lara-Viveros F, Ventura-Maza A, Ehsan M, et al. Cd and Pb content in soil and plants of different crops irrigated with wastewater in the Mezquital Valley, Hidalgo, Mexico[J]. Revista Internacional de Contaminacion Ambiental, 2015, 31(2): 127-132.
[35]
Aslam S, Sharif F, Khan A U. Effect of lead and cadmium on growth of Medicago sativa L. and their transfer to food chain[J]. Journal of Animal and Plant Sciences, 2015, 25(2): 472-477.
[36]
王晓娟, 王文斌, 杨龙, 等. 重金属镉(Cd)在植物体内的转运途径及其调控机制[J]. 生态学报, 2015, 35(23): 7921-7929.
WANG Xiao-juan, WANG Wen-bin, YANG Long, et al. Transport pathways of cadmium(Cd) and its regulatory mechanisms in plant[J]. Acta Ecologica Sinica, 2015, 35(23): 7921-7929.
[37]
Verbruggen N, Hermans C, Schat H, et al. Mechanisms to cope with arsenic or cadmium excess in plants[J]. Current Opinion in Plant Biology, 2009, 12(3): 364-372. DOI:10.1016/j.pbi.2009.05.001
[38]
Seregin I V, Kozhevnikova A D. Roles of root and shoot tissues in transport and accumulation of cadmium, lead, nickel, and strontium[J]. Russian Journal of Plant Physiology, 2008, 55(1): 1-22. DOI:10.1134/S1021443708010019
[39]
李跃鹏, 尹华, 叶锦韶, 等. 紫花苜蓿吸收水溶液中Cd2+过程的阳离子交换[J]. 环境科学, 2011, 32(11): 3341-3347.
LI Yue-peng, YIN Hua, YE Jin-shao, et al. Cation exchanges during the process of Cd2+ absorption by alfalfa in aqueous solutions[J]. Environmental Science, 2011, 32(11): 3341-3347.
[40]
林双双. AM真菌调节紫花苜蓿对重金属元素Cd的吸收和分配策略[D]. 兰州: 兰州大学, 2013.
LIN Shuang-shuang. Strategies of AM fungi on growth and uptake, distribution of cadmium by alfalfa(Medicago sativa L.)[D]. Lanzhou:Lanzhou University, 2013. http://cdmd.cnki.com.cn/Article/CDMD-10730-1016190593.htm
[41]
Liu M H, Sun J, Li Y, et al. Nitrogen fertilizer enhances growth and nutrient uptake of Medicago sativa inoculated with Glomus tortuosum grown in Cd-contaminated acidic soil[J]. Chemosphere, 2017, 167: 204-211. DOI:10.1016/j.chemosphere.2016.09.145
[42]
陈保冬. 丛枝菌根减轻宿主植物锌、镉毒害机理研究[D]. 北京: 中国农业大学, 2002.
CHEN Bao-dong. Role of arbuscular mycorrhizae in alleviation of zinc and cadmium phytotoxicity[D]. Beijing:China Agricultural University, 2002. http://cdmd.cnki.com.cn/Article/CDMD-10019-2006012922.htm
[43]
黄艺, 陈有鑑, 陶澍. 污染条件下VAM玉米元素积累和分布与根际重金属形态变化的关系[J]. 应用生态学报, 2002, 13(7): 859-862.
HUANG Yi, CHEN You-jian, TAO Shu. Uptake and distribution of Cu, Zn, Pb and Cd in maize related to metals speciation change in rhizosphere[J]. Chinese Journal of Applied Ecology, 2002, 13(7): 859-862.
[44]
Hattab S, Boussetta H, Banni M. Influence of nitrate fertilization on Cd uptake and oxidative stress parameters in alfalfa plants cultivated in presence of Cd[J]. Journal of Soil Science and Plant Nutrition, 2014, 14(1): 89-99.
[45]
Zaccheo P, Crippa L, Pasta V D M. Ammonium nutrition as a strategy for cadmium mobilisation in the rhizosphere of sunflower[J]. Plant and Soil, 2006, 283(1): 43-56.
[46]
刘芳, 陈娇君, 刘世亮, 等. 柠檬酸对褐土中DTPA提取态铜、镉含量及对紫花苜蓿吸收铜、镉的影响[J]. 环境工程学报, 2013, 7(7): 2781-2787.
LIU Fang, CHEN Jiao-jun, LIU Shi-liang, et al. Effect of citric acid(CA) on DTPA extractable Cu & Cd content in cinnamon soil and Cu & Cd uptake by alfalfa[J]. Chinese Journal of Environmental Engineering, 2013, 7(7): 2781-2787.
[47]
Gharaibeh M A, Marschner B, Heinze S. Metal uptake of tomato and alfalfa plants as affected by water source, salinity, and Cd and Zn levels under greenhouse conditions[J]. Environmental Science and Pollution Research, 2015, 22(23): 18894-18905. DOI:10.1007/s11356-015-5077-3
[48]
Parlak K U, Yilmaz D D. Ecophysiological tolerance of Lemna gibba L. exposed to cadmium[J]. Ecotoxicology & Environmental Safety, 2013, 91(4): 79-85.
[49]
Tanaka K, Fujimaki S, Fujiwara T, et al. Quantitative estimation of the contribution of the phloem in cadmium transport to grains in rice plants(Oryza sativa L.)[J]. Soil Science and Plant Nutrition, 2007, 53(1): 72-77. DOI:10.1111/j.1747-0765.2007.00116.x
[50]
张玉秀, 于飞, 张媛雅, 等. 植物对重金属镉的吸收转运和累积机制[J]. 中国生态农业学报, 2008, 16(5): 1317-1321.
ZHANG Yu-xiu, YU Fei, ZHANG Yuan-ya, et al. Uptake, translocation and accumulation of cadmium in plant[J]. Chinese Journal of Eco-Agriculture, 2008, 16(5): 1317-1321.
[51]
刘利, 郝小花, 田连福, 等. 植物吸收、转运和积累镉的机理研究进展[J]. 生命科学研究, 2015, 19(2): 176-184.
LIU Li, HAO Xiao-hua, TIAN Lian-fu, et al. Research progresses on the mechanism of Cd absorption, transport and accumulation in plant[J]. Life Science Research, 2015, 19(2): 176-184.
[52]
Qu J, Wang L, Yuan X, et al. Effects of ammonium molybdate on phytoremediation by alfalfa plants and (im)mobilization of toxic metals in soils[J]. Environmental Earth Sciences, 2011, 64(8): 2175-2182. DOI:10.1007/s12665-011-1045-5
[53]
Niu Z X, Sun L N, Sun T H, et al. Evaluation of phytoextracting cadmium and lead by sunflower, ricinus, alfalfa and mustard in hydroponic culture[J]. Journal of Environmental Sciences(China), 2007, 19(8): 961-967. DOI:10.1016/S1001-0742(07)60158-2
[54]
Singh A, Eapen S, Fulekar M H. Potential of Medicago sativa for uptake of cadmium from contaminated environment[J]. Romanian Biotechnological Letters, 2009, 14(1): 4164-4169.
[55]
Elouear Z, Bouhamed F, Boujelben N, et al. Application of sheep manure and potassium fertilizer to contaminated soil and its effect on zinc, cadmium and lead accumulation by alfalfa plants[J]. Sustainable Environment Research, 2016, 26(3): 131-135. DOI:10.1016/j.serj.2016.04.004
[56]
Cui W T, Chen H P, Zhu K K, et al. Cadmium-induced hydrogen sulfide synthesis is involved in cadmium tolerance in Medicago sativa by reestablishment of reduced(Homo) glutathione and reactive oxygen species homeostases[J]. Plos One, 2014, 9(10): e109669. DOI:10.1371/journal.pone.0109669
[57]
Li L, Wang Y Q, Shen W B. Roles of hydrogen sulfide and nitric oxide in the alleviation of cadmium-induced oxidative damage in alfalfa seedling roots[J]. Biometals, 2012, 25(3): 617-631. DOI:10.1007/s10534-012-9551-9
[58]
Han Y, Zhang J, Chen X Y, et al. Carbon monoxide alleviates cadmium-induced oxidative damage by modulating glutathione metabolism in the roots of Medicago sativa[J]. New Phytologist, 2008, 177(1): 155-166.
[59]
Cui W T, Gao C Y, Fang P, et al. Alleviation of cadmium toxicity in Medicago sativa by hydrogen-rich water[J]. Journal of Hazardous Materials, 2013, 260: 715-724. DOI:10.1016/j.jhazmat.2013.06.032
[60]
Cui W T, Fu G Q, Wu H H, et al. Cadmium-induced heme oxygenase-1 gene expression is associated with the depletion of glutathione in the roots of Medicago sativa[J]. Biometals, 2011, 24(1): 93-103. DOI:10.1007/s10534-010-9377-2
[61]
Jin Q J, Zhu K K, Xie Y J, et al. Heme oxygenase-1 is involved in ascorbic acid-induced alleviation of cadmium toxicity in root tissues of Medicago sativa[J]. Plant and Soil, 2013, 366(1/2): 605-616.
[62]
Cui W T, Li L, Gao Z Z, et al. Haem oxygenase-1 is involved in salicylic acid-induced alleviation of oxidative stress due to cadmium stress in Medicago sativa[J]. Journal of Experimental Botany, 2012, 63(15): 5521-5534. DOI:10.1093/jxb/ers201
[63]
Fu G Q, Zhang L F, Cui W T, et al. Induction of heme oxygenase-1 with beta-CD-hemin complex mitigates cadmium-induced oxidative damage in the roots of Medicago sativa[J]. Plant and Soil, 2011, 345(1/2): 271-285.
[64]
Sobrino-Plata J, Ortega-Villasante C, Laura Flores-Caceres M, et al. Differential alterations of antioxidant defenses as bioindicators of mercury and cadmium toxicity in alfalfa[J]. Chemosphere, 2009, 77(7): 946-954. DOI:10.1016/j.chemosphere.2009.08.007
[65]
黄晶, 凌婉婷, 孙艳娣, 等. 丛枝菌根真菌对紫花苜蓿吸收土壤中镉和锌的影响[J]. 农业环境科学学报, 2012, 31(1): 99-105.
HUANG Jing, LING Wan-ting, SUN Yan-di, et al. Impacts of arbuscular mycorrhizal fungi inoculation on the uptake of cadmium and zinc by alfalfa in contaminated soil[J]. Journal of Agro-Environment Science, 2012, 31(1): 99-105.
[66]
Wang Y P, Huang J, Gao Y Z. Arbuscular mycorrhizal colonization alters subcellular distribution and chemical forms of cadmium in Medicago sativa L. and resists cadmium toxicity[J]. Plos One, 2012, 7(11): e48669. DOI:10.1371/journal.pone.0048669
[67]
Rahman M A, Zada M, Lee D-G, et al. Identification of copper and cadmium induced genes in alfalfa leaves through annealing control primer based approach[J]. Journal of the Korean Society of Grassland Science, 2015, 35(3): 264-268. DOI:10.5333/KGFS.
[68]
张春荣, 夏立江, 杜相革, 等. 镉对紫花苜蓿种子萌发的影响[J]. 中国农学通报, 2004, 20(5): 253-255.
ZHANG Chun-rong, XIA Li-jiang, DU Xiang-ge, et al. Effect of cadmium germination of Medicago sativa seeds[J]. Chinese Agricultural Science Bulletin, 2004, 20(5): 253-255.
[69]
慈恩, 高明, 王子芳, 等. 镉对紫花苜蓿种子萌发与幼苗生长的影响研究[J]. 中国生态农业学报, 2007, 15(1): 96-98.
CI En, GAO Ming, WANG Zi-fang, et al. Effects of cadmium on seed germination and growth of alfalfa[J]. Chinese Journal of Eco-Agriculture, 2007, 15(1): 96-98.
[70]
韩多红, 孟红梅. 重金属镉对阿尔冈金和金皇后种子发芽和出苗的影响[J]. 种子, 2006, 25(10): 71-72.
HAN Duo-hong, MENG Hong-mei. Effect of cadmium stress on germination and seedlings of Algonuin and Golden-Empress[J]. Seed, 2006, 25(10): 71-72. DOI:10.3969/j.issn.1001-4705.2006.10.022
[71]
韩多红, 孟红梅, 王进, 等. 镉对紫花苜蓿种子萌发等生理特性的影响[J]. 干旱地区农业研究, 2007, 25(5): 151-154, 171.
HAN Duo-hong, MENG Hong-mei, WANG Jin, et al. Effect of Cd2+ on physiological characteristics of alfalfa[J]. Agricultural Research in the Arid Areas, 2007, 25(5): 151-154, 171.
[72]
Neumann H, Bode-Kirchhoff A, Madeheim A, et al. Toxicity testing of heavy metals with the Rhizobium-legume symbiosis:High sensitivity to cadmium and arsenic compounds[J]. Environmental Science and Pollution Research International, 1998, 5(1): 28-36. DOI:10.1007/BF02986371
[73]
慈恩, 朱洁, 高明, 等. 镉对紫花苜蓿生长和结瘤固氮的影响[J]. 安徽农业科学, 2010, 38(12): 6421-6423, 6476.
CI En, ZHU Jie, GAO Ming, et al. Effects of cadmium on growth, nodulation and nitrogen fixation of alfalfa(Medicago sativa)[J]. Journal of Anhui Agricultural Sciences, 2010, 38(12): 6421-6423, 6476. DOI:10.3969/j.issn.0517-6611.2010.12.123
[74]
徐苏凌, 方勇, 邢承华. 镉胁迫对紫花苜蓿生长及结瘤的影响[J]. 江西农业大学学报, 2008, 30(6): 1049-1052.
XU Su-ling, FANG Yong, XING Cheng-hua. Effect of cadmium stress on growth and nodulation in alfalfa[J]. Acta Agriculturae Universitatis Jiangxiensis, 2008, 30(6): 1049-1052.
[75]
Zribi K, Djebali N, Mrabet M, et al. Physiological responses to cadmium, copper, lead, and zinc of Sinorhizobium sp. strains nodulating Medicago sativa grown in Tunisian mining soils[J]. Annals of Microbiology, 2012, 62(3): 1181-1188. DOI:10.1007/s13213-011-0358-7
[76]
Ortega-Villasante C, Hernandez L E, Rellan-Alvarez R, et al. Rapid alteration of cellular redox homeostasis upon exposure to cadmium and mercury in alfalfa seedlings[J]. New Phytologist, 2007, 176(1): 96-107. DOI:10.1111/nph.2007.176.issue-1
[77]
吴旭红. 三个苜蓿品种对镉污染的生理生态反应及抗性比较[J]. 生态环境, 2005, 14(5): 658-661.
WU Xu-hong. Comparison of the resistance of three varieties of alfalfa to cadmium stress[J]. Ecology and Environment, 2005, 14(5): 658-661.