土壤亚铁、镉对水稻2种抗氧化酶和植株富集镉量的影响

叶欣怡,赵杏,王小鹏,钟一铭,杨京平(浙江大学环境与资源学院,杭州310058)

土壤亚铁、镉对水稻2种抗氧化酶和植株富集镉量的影响

叶欣怡,赵杏,王小鹏,钟一铭,杨京平*
(浙江大学环境与资源学院,杭州310058)

摘要我国南方潴育及潜育型水稻土中积累有大量亚铁,有研究表明土壤亚铁会影响镉在植株中的富集及镉对植株的氧化性胁迫.试验设置4个土壤Fe(2+)水平(外源加入亚铁分别为0 mg/kg、100 mg/kg、200 mg/kg和400 mg/kg)和2个Cd(2+)水平(外源加入镉分别为0 mg/kg和5 mg/kg),研究不同亚铁和镉的共同作用对孕穗期水稻叶片脂质过氧化、抗氧化酶活性以及对根膜和植株中重金属累积量的影响.在无外源亚铁添加的条件下,镉使叶片中脂质过氧化的监测指标丙二醛(malondialdehyde,MDA)含量下降了31.1%,同时抑制了超氧化物歧化酶(superoxide dismutase,SOD)和过氧化物酶(peroxidase,POD)活性.随着土壤亚铁量的增加,特别是在外源添加亚铁400 mg/kg时,镉对水稻植株产生的上述影响得到了缓解.随着土壤亚铁量的升高,水稻的根膜、根和叶片对重金属镉的富集呈下降的趋势,且试验表明水稻根及叶片对镉的积累与根际膜中含镉量呈显著正相关.研究表明土壤中亚铁量的增加会降低水稻中镉的积累.

关键词水稻;根膜;脂质过氧化;超氧化物酶;过氧化物酶

浙江大学学报(农业与生命科学版) 42(1):89～98,2016

Journal of Zhejiang University(Agric.&Life Sci.)

http://www.journals.zju.edu.cn/agr

E-mail:zdxbnsb@zju.edu.cn

第一作者联系方式:叶欣怡(http://orcid.org/0000-0002-9767-5439),E-mail:546784861@qq.com

Effects of soil Fe2+and Cd2+on activities of antioxidant enzymes and Cd accumulation in rice plants.Journal of Zhejiang University(Agric.&Life Sci.),2016,42(1):89-98

YE Xinyi,ZHAO Xing,WANG Xiaopeng,ZHONG Yiming,YANG Jingping*(College of Environmental and Resource Sciences,Zhejiang University,Hangzhou 310058,China)

Summary Divalent heavy metal cation cadmium(Cd2+)causes phytotoxicity in plants.The high bioaccumulation index in plants and soil will also threat the human health through food chain.It has been shown that Cd will inhibit germination of seeds and exert a wide range of adverse effects on growth and metabolism of plants.It was reported that high concentration of Fe2+in paddy soil could exert some impacts on plant growth and Cd2+accumulation.Cadmium and ferrous with high concentration in soil,are known to cause oxidative damage to plants either directly or indirectly by triggering an increased level of production of reactive oxygen species(ROS).Plants have antioxidative enzymes,such as superoxide dismutase(SOD),catalase and peroxidase(POD),which can scavenge ROS to avoid oxidative damage.Malondialdehyde(MDA)level is used as an index of lipid peroxidation under stressful conditions in plants.Therefore activity of antioxidative enzymes(SOD and POD)and MDA level can be used to monitor the oxidative stress of plants.In anaerobic waterlogged environment,rice can form iron plaque ____around root surface and screen metals by adsorption and co-precipitation.Thus,the availability and balance of Fe/Cd in the rhizosphere of rice will be influenced.Many researchers investigated the impacts of ferrous and cadmium respectively on rice growth,while few efforts were made in interaction of these two metal ions,which exist in production conditions.

In order to investigate mechanisms of Fe and Cd stress on rice in real production condition,the pot experiment with 4 soil Fe2+levels(577,677,777 and 977 mg/kg)and 2 soil Cd2+concentrations(0.413 and 5.413 mg/kg) was conducted.The rice cultivar used in the experiment was Hang43.Shoots of rice collected at booting stage were ground with liquid nitrogen and were homogenized in phosphate buffer(p H 7.8).The extracted supernatant was used to assay SOD activity,POD activity and MDA level,by NBT method,guaiacol colorimetric method and the thiobarbituric acid method,respectively.Fe and Cd concentrations in shoots and roots were determined by flame atomic absorption spectrophotometer(FAAS)after digestion procedures.Fe and Cd contents in iron plaque on the roots were extracted using dithionite-citrate-bicarbonate(DCB)method,and were measured by AAS.

The experimental results showed that ferrous and cadmium in soil had interaction on the activities of lipid peroxidation,antioxidative enzymes and uptakes of these two metals.Cd2+remarkably decreased MDA levels by about 31.1%,meanwhile depressed activities of superoxide dismutase(SOD)and peroxidase(POD)enzyme.Whereas,those adverse effects were mediated by increasing Fe2+concentration in soil(especially at 977 mg/kg Fe2+).Variations of SOD activity and POD activity had similar trend in all the treatments,though POD activity was more stabilized,indicating SOD undertakes more protection responsibility under experimental conditions.Fe contents in iron plaque maintained 1-2 g/kg under all treatments,while Cd concentration in iron plaque declined quickly with the increase of soil ferrous level.Ferrous in soil stimulated the uptakes of Cd at a certain range but a relatively higher ferrous concentration in soil decreased the Cd contents in roots and shoots.

It can be concluded that iron plaque helps to screen Cd2+in the rhizosphere and inhibits the uptake of Cd2+in rice.Fe2+in soil can alleviate the stress of Cd2+by restraining the accumulation of Cd2+.

Key words rice;iron plaque;lipid peroxides;superoxide dismutase;peroxidase

镉能经食物链的生物富集和生物放大作用毒害高等动物[1-2],因而受到广泛关注.近年来的研究表明,植物非必需营养元素镉也具有植物毒性.镉能抑制光合作用[3]、破坏呼吸系统和造成营养代谢紊乱[2,4-7],从而影响植物生长,导致植物死亡.水稻是我国主要粮食之一,在稻田生态系统中,不仅土壤重金属镉会对水稻产生毒害作用,有时植物必需微量元素铁也可能威胁水稻生长[8 11].长期淹水的稻田土壤因处于厌氧状态而积累大量亚铁,植物吸收过多亚铁将会出现代谢失调、营养紊乱[8]、光合作用能力降低[9-10]等一系列中毒现象,致使作物减产甚至死亡.铁和镉具有重叠的生理功能影响区[12],它们均在植物光合作用系统、氧化还原系统、营养代谢系统发挥作用,因而在现实条件下它们对水稻生长的影响可能存在交互作用[13].有研究表明,植株对镉的吸收与环境中铁的状态和含量有关[6,14].

镉及过量亚铁造成的植物毒害主要是产生活性氧自由基(reactive oxygen species,ROS)[6,8,11].活性氧会造成植物氧化性损伤,破坏脂质、蛋白质、核酸等生物大分子[15].植物自身的抗氧化酶系统,可以清除活性氧自由基(ROS)[2],从而减少氧化性损伤.其中,超氧化物歧化酶(superoxide dismutase,SOD)可以将超氧阴离子(.)歧化成H2O2和O2[2,16];过氧化物酶(peroxidase,POD)以愈创木酚为电子受体,利用H2O2氧化植物体内有机物或无机物[2].丙二醛(malondialdehyde,MDA)是植物膜脂质过氧化的产物[15],可代表生物膜的损伤程度,是检验氧化胁迫重要指标之一[2].研究表明,植株通过增加SOD、POD活性来抵御亚铁毒害[10,17],但长期或过量亚铁胁迫也会使SOD、POD活性受到抑制[17-18].镉也会对水稻抗氧化酶系统产生影响,但文献所述的影响并不一致[2,7,19-20].如SHAH等[2]认为镉会造成水稻脂质过氧化,刺激SOD和POD活性;CHIEN等[7]研究表明镉刺激水稻叶片中POD活性,但抑制了SOD活性;邵国胜等[15]则认为镉能增加MDA含量,却抑制了SOD和POD活性.镉对植株抗氧化酶系统的影响可能与不同品系植株本身、生长时期及处理条件相关.

土壤在厌氧环境下,水稻根际释放的氧气和氧化剂可以将Fe2+氧化成Fe3+,铁的氧化物或氢氧化物将附着于根表,形成根膜[5,21].根膜可以吸附、共沉淀多种元素[21-22],进而影响这些元素在根际的含量和植物可用性,改变植株对它们的吸收迁移能力[23-24].研究表明,水稻根际膜能影响镉的吸收迁移,可以减少[5,23]或增加[1,24]植株对镉的吸收,这可能与植株品系、根际膜厚度和植株生长时期等因素相关[5,23].

《全国土壤污染状况调查公报》显示我国土壤镉污染较为严重,镉米仍有可能成为粮食安全的隐患[25-26].调查表明我国南方水稻土中有大量亚铁累积[27],在实际水稻种植条件下,土壤亚铁会对镉的毒害作用产生影响.以往研究多集中于2种金属的单独作用,虽然也有通过水培试验分析其交互作用[15-20,26],但水培条件与实际土壤状况差异较大.因此,本试验将通过盆栽模拟水稻实际生长环境,研究在南方土壤中亚铁含量较高的条件下,以对金属有一定富集量且抗氧化酶系统受植株衰老影响较小的孕穗期的水稻为研究对象,探讨含大量亚铁的南方潜育型土壤中铁、镉对水稻部分抗氧化酶活性,及铁、镉吸收的影响.从而为探索实际生产过程中水稻重金属胁迫的机制提供一定的理论基础.

1　材料与方法

1.1供试材料

盆栽试验在浙江大学农业试验站网室内进行.供试水稻品种为杭43(单季稻),水稻秧苗来自杭州市农业科学研究院.供试土壤采自杭州市华家池稻田(长期种植的水稻田),为0～20 cm耕层土壤,土壤基本理化性质如表1.

1.2试验处理

将自然风干并过2 mm筛的稻田土壤,按每桶7.5 kg干土装入桶中.试验采用随机分组的方式,设置4个土壤Fe2+水平F1、F2、F3和F4(外源加入亚铁量分别为0 mg/kg、100 mg/kg、200 mg/kg和400 mg/kg);2个Cd2+水平C0,C1(外源加入总镉量分别为0 mg/kg,5 mg/kg),共8个处理,每个处理3个重复(共24个桶).根据每种处理所要求的亚铁及镉含量,以硫酸亚铁和硫酸镉溶液的形式拌入土壤,混合均匀.将处理过的土重新装入桶中,淹水(水面超过土面约1 cm)钝化培养1个月.土壤添加亚铁和镉处理后每种处理土壤总亚铁和镉含量见表2.水稻种植为每桶3穴,每穴2株水稻(144株水稻).

每盆水稻施入尿素225 kg/hm2(以纯氮计)并分别以225 kg/hm2和75 kg/hm2的量施入磷肥(过磷酸钙),钾肥(氯化钾).每盆土表面积为0.049 m2,土深为25 cm.每盆施入尿素、过磷酸钙和氯化钾的量分别为1.103 g、1.102 g和0.367 g.

1.3样品采集及测定

1.3.1水稻生化指标测定

在水稻孕穗期(移栽后51 d)采集水稻顶部3片完全展开叶片,在液氮环境下研磨,并用p H 7.8的磷酸缓冲液提取叶片中所需测定生化物质.SOD活性采用氮蓝四唑(NBT)还原法[28];POD活性采用愈创木酚比色法[29];MDA含量用硫代巴比妥酸(TBA)比色反应测定[28].

1.3.2水稻叶片叶绿素测定

用SPAD-502微型叶绿素计对孕穗期水稻顶部3片完全展开叶片进行测量,每片叶子取3个点位(距叶片基部1/2处及其上下各约3 cm的位置)进行测量并取平均值作为该张叶片的SPAD值.

1.3.3水稻根膜提取及金属含量的测定

用DCB(dithionite citrate bicarbonate)法提取水稻根膜中的铁和镉[30-31].采集孕穗期水稻根,用自来水冲去泥土后用去离子水冲洗3次.将根放入150-m L锥形瓶中加入60 m L提取液(摩尔浓度0.3

mol/L柠檬酸钠和0.1 mol/L碳酸氢钠)和1.2 g硫代硫酸钠,在27℃条件下振荡2 h.将提取液转移至100 m L容量瓶定容,用火焰原子吸收分光光度法(FAAS)测定其含铁和镉量.

1.3.4水稻植株中金属含量的测定

采用微波消解-火焰原子吸收法测定,用万分之一天平准确称取105℃杀青2 h并在80℃烘干至恒量的水稻叶片及提取过根膜的根0.2 g于聚四氟乙烯消解管中,加入5 m L HNO3、1 m L HF和1 m L H2O2.先在120℃下预消解20 min后进行微波消解,之后在150℃下赶酸,剩余消解液定容至100-m L的容量瓶中,用火焰原子吸收分光光度法(FAAS)测定其含铁和镉量.

1.4数据处理

利用SPSS 20.0进行双因素方差分析,用邓肯(Duncan)检验分析各处理间差异性(显著性水平α=0.05).

2　结果与分析

2.1铁、镉相互作用对水稻生理生化指标的影响

在铁、镉共同处理下,表征水稻叶片叶绿素水平的SPAD值没有显著变化(图1).通过双因素方差分析,外源亚铁和镉对水稻叶片MDA含量存在交互作用.在无镉处理(C0)下,水稻叶片中MDA含量随着土壤亚铁量的增加而呈减少的趋势,特别是在F3和F4处理下有显著降低(图1),大约是F1处理下MDA含量的45%.相关性分析表明MDA与叶片中含铁量呈显著负相关(表3).在F1处理下,有镉处理(C1)显著降低了叶片MDA含量,是无镉处理(C0)下MDA含量的68.9%.这表明在一定亚铁含量下(F1)镉的存在会加剧植株营养代谢失调.从整体来看,在有镉处理(C1)下,水稻叶片中MDA含量在试验所设所有亚铁含量条件下保持稳定水平.

SOD与POD是植物减少活性氧(ROS)损伤的抗氧化酶系统[1].图2所示,在F1和F2条件下,SOD活性在土壤高镉处理(C1)时明显低于无外源添加镉(C0)的处理,镉在这2个亚铁处理下大约抑制了60% 的SOD活性.随着外源亚铁处理量的增加,在C1处理下SOD活性在不断增强,并逐渐与在C0处理下SOD活性水平相近似.这表明亚铁量的提高能减少镉对植株的影响.相关性分析也表明,SOD活性与叶片中含镉量呈显著负相关,而与叶片中的含铁量呈正相关(表3).在镉污染的土壤中,亚铁量的增加将会刺激SOD活性.在试验所设亚铁条件下,镉抑制了POD活性.在不同处理下,POD活性变化与SOD活性变化有着相似的趋势.相关性分析表明,两者之间存在显著正相关.然而,POD活性变化幅度比SOD活性变化幅度小,表明在本试验的镉和亚铁条件下,SOD发挥了主要的保护作用,而POD处于较为次要的地位.在无外源添加镉时,F3、F4处理使得SOD、POD活性相对于F1、F2处理下均有所下降,这是由于亚铁胁迫超过水稻自身抵御能力,产生过量的活性氧(ROS)消耗了这2种抗氧化酶[17,31].

2.2铁、镉相互作用对植株根膜、根及叶片中铁、镉含量的影响

在本试验条件下,根膜中铁元素含量不因土壤中亚铁或镉量的变化而呈显著性差异,其质量分数基本维持在1～2 g/kg(图3).对于根膜中的含镉量而言,在无镉处理(C0)下,根膜中镉的含量随土壤亚铁浓度呈现先降低后增加的趋势,在F3处理时达到最低,但整体而言变化幅度较小.土壤在高镉(C1)条件下,根膜中含镉量随着土壤中亚铁量的增加呈明显减少的趋势,且在F4处理下其含量与F0处理下的含量接近.这可能是由于亚铁离子的竞争作用使得镉向根际微区转移能力降低,从而表现出随着土壤亚铁浓度的增加,土壤中的镉会更少地吸附沉积在根膜中.

本试验所设土壤亚铁水平(577～977 mg/kg)对根的含铁量影响不显著(图4),根中含铁量范围维持在2.25～3.75 g/kg.这可能是在较高亚铁条件下,根通过限制吸收,减少亚铁积累的一种自我保护机制.土壤在低镉(C0,外源加镉0 mg/kg)条件下,根中所积累的镉含量维持在一个稳定较低的水平(约11.5 mg/kg),且不随外源铁变化而有所改变,这与根膜中镉始终维持在一定水平有关.但是,土壤在高镉(C1,外源加镉5 mg/kg)条件下,根对镉的积累会随土壤亚铁量的变化而有波动,呈先增加后减少的趋势,在F2处理(土壤含Fe2+量为677 mg/kg)时镉达到最高值(102.4 mg/kg).这表明一定量的土壤亚铁能刺激根对镉的富集,但随着土壤中亚铁的升高又会阻碍根对镉的吸收.

对水稻叶片中含铁量分析发现,叶片中含铁量随土壤亚铁量的增加而增加,而外源土壤镉的添加减少了铁在叶片中的积累(图5).叶片中的含镉量与根中的含镉量有着一致的变化趋势,即随着含亚铁量的增加呈先增加后减少的趋势,在F2处理(土壤含Fe2+量为677 mg/kg)时镉达峰值(12.1 mg/kg).相关性分析(表4)显示,叶片中的含镉量与根及根膜中含镉量呈显著正相关,这反映了根膜中的镉是植株吸收、累积镉的主要来源.此外,正是由于亚铁在根膜与镉的竞争减少了根膜的含镉量,从而抑制了植株对镉的积累,减缓了镉对植株的影响.刘文菊等[32]的研究也表明,根际膜的存在可以抑制植株对镉的吸收.同时,本试验还发现,根对镉的富集远大于叶片,这与CHIEN等[7]的研究结果一致.

3　讨论

前人研究表明,铁是植物必需营养元素,也是叶绿素形成的基础元素,缺铁会使水稻黄化[33],过量的亚铁会使水稻积累大量氧自由基,氧化叶绿素[10],同样导致叶绿素水平下降[9].此外,有报道称镉会使植物叶绿素水平减少[15,34].但本试验未能验证以上结果,这可能是因为SPAD值作为间接指标受到诸如氮素等营养水平及植株自身条件等因素的综合影响,所以并不能敏感的反映较高含量下外源亚铁变化对植株的影响.同时,在高亚铁环境下,试验所设的含镉量不足以影响叶绿素水平.有研究表明只有在高镉处理下,水稻叶片SPAD值才会有所降低[15].

孕穗期是水稻由营养生长转变为生殖生长过渡期[35].研究表明水稻叶片对镉的富集呈现分蘖期＜孕穗期＜抽穗期的趋势[36].水稻抗氧化酶系统受到逆境胁迫和植株衰老2种作用的影响,在生育晚期,植株衰老将成为主导因素[36],使得抗氧化酶系统对金属胁迫将不再敏感.丙二醛(MDA)是植物膜脂质过氧化的产物[15].多数实验研究表明,在过量亚铁和镉的胁迫下,诱发的活性氧自由基将会攻击膜脂,使得水稻MDA含量增加[37 38].然而本实验结果显示,水稻叶片中MDA含量随亚铁量增加呈下降趋势,这可能是在高亚铁胁迫下植株机体本身出现了失调现象[39].在F1处理下,镉使得MDA含量大幅减少,这可能是由于外源镉的施入加剧了植株代谢失调.随着外源亚铁量增加,镉的施入对MDA量不再有显著影响,这可能是高亚铁减少了实验所设土壤含镉量对水稻叶片MDA的不利影响.相关性分析表明,MDA含量与SOD和POD活性不相关.在实验条件下,镉抑制了SOD和POD活性,尽管这与邵胜国等[15]的研究结果相一致,但本实验表明土壤在不同亚铁量下镉对SOD、POD活性的抑制能力并不相同.这说明镉对植株的氧化胁迫会受到土壤中亚铁的影响,在相对较高的亚铁量下(777～977 mg/kg)镉对SOD、POD活性的抑制能力减弱.在不同处理下,POD比SOD活性变化幅度小,这表明本实验在镉和亚铁条件下,SOD发挥了主要的保护作用,这与王贵民等[17]的研究结果一致.值得注意的是,在无外源添加镉时,F3、F4处理使得SOD、POD活性有所下降,这可能是由于亚铁胁迫超过水稻自身抵御能力,产生过量的活性氧(ROS)消耗了这2种抗氧化酶[17,31].

史锟等[40]研究表明受到根表铁的富集点位所限,在土壤较高亚铁量下,根表所能富集的铁胶膜量趋于稳定,这与本实验根膜中的含铁量并不因土壤中亚铁量变化而有显著改变的结论一致.然而,根膜中的含镉量却随着土壤中亚铁量的增加而降低,这可能是由于亚铁离子的竞争作用使得镉向根际微区转移的能力降低,从而表现出随着土壤亚铁量的增加,土壤中的镉会更少地吸附沉积在根膜中,这与史锟等[40]研究的水培下孕穗期水稻根膜中铁、镉含量结果相似.

本实验根中含镉量随亚铁量增加呈先增加后减少的趋势,表明土壤在高镉条件下,土壤亚铁量增加在一定程度上刺激了镉向根的富集,但随着土壤亚铁的进一步提高,又会阻碍根对镉的吸收富集.前人研究表明,水稻可以通过Fe2+跨膜运输蛋白(Ⅰ)或借助Fe3+载体(Ⅱ)吸收铁.Ⅱ方式是缺铁条件下水稻吸收铁的主要方式.本试验土壤在所设亚铁条件下,水稻主要通过Ⅰ方式吸收铁元素.Ⅰ方式所涉及的铁载体蛋白也可以有效地运输镉[6,14,33],外源亚铁量从F1(577 mg/kg)增加到F2(677 mg/kg)时,可能刺激水稻更多地通过Ⅰ方式吸收铁,产生了更多亲附镉的铁载体,从而使根富集了更多镉.但是,随着亚铁量的升高,其与镉的竞争加强,使得根对镉的富集能力逐渐降低.同时高外源亚铁也会抑制铁载体的表达[6],从而减少植株对铁和镉的吸收.此外,根膜中镉量的降低也可能是根中镉量减少的原因之一.叶片对镉的富集受到根和根膜富集镉量的影响,随着土壤亚铁量的增加呈下降趋势,这也可能是随着亚铁量增加,镉对植株MDA含量以及POD 和SOD活性的影响变得不显著的原因之一.

4　结论

4.1在本试验条件下的土壤中亚铁和镉含量的增加对水稻叶片SPAD值没有显著的影响.

4.2在577 mg/kg的亚铁条件下,镉显著降低了叶片中MDA含量,加剧了水稻营养代谢失调.但是随着土壤亚铁量的升高,镉所产生的不利影响变得不再显著.土壤亚铁的增加减少了植株对镉的吸收和富集,这也是高亚铁能够减少镉对水稻叶片MDA含量以及SOD和POD活性的影响的部分原因.

4.3镉的存在抑制了SOD和POD活性,但其抑制能力与土壤中含铁量有关.在试验所设较低亚铁条件下镉对2种抗氧化酶活性的抑制能力要高于试验所设较高亚铁条件下的抑制能力.镉也抑制了铁在水稻叶片的富集,这表明铁和镉在水稻吸收和富集金属过程中存在竞争关系.

4.4试验表明水稻根及叶片积累富集镉的量与根膜中含镉量呈正相关.控制镉在植株根膜的积累可以作为减少植株吸收富集镉的一个方式.随着土壤含铁量增加,镉在根膜中含量减少.由于土壤高铁量所产生根膜的屏蔽作用使得镉向植株迁移的可能性降低.此外,土壤中含铁量较高会阻碍高亲和性铁载体的表达,从而减少了植物对镉的吸收和积累.

参考文献(References):

[1]陈爱葵,王茂意,刘晓海,等.水稻对重金属镉的吸收及耐性机理研究进展.生态科学,2013,32(4):514-522.CHEN A K,WANG M Y,LIU X H,et al.Research progress on the effect of cadmium on rice and its absorption and tolerance mechanisms.Ecological Science,2013,32(4):514-522.(in Chinese with English abstract)

[2]SHAH K,KUMAR R G,VERMA S,et al.Effect of cadmium on lipid peroxidation,superoxide anion generation and activities of antioxidant enzymes in growing rice seedlings.Plant Science,2001,161(6):1135-1144.

[3]张杰,梁永超,娄运生,等.镉胁迫对两个水稻品种幼苗光合参数,可溶性糖和植株生长的影响.植物营养与肥料学报,2005,11(6):774-780.ZHANG J,LIANG Y C,LOU Y S,et al.Effect of cadmium on photosynthesis parameters,leaf soluble sugar and plant growth in two rice cultivars.Plant Nutrition and Fertilizer Science,2005,11(6):774-780.(in Chinese with English abstract)

[4]李欢,陈亮,潘琼,等.水稻重金属生态毒性诊断研究进展.环境与可持续发展,2013,37(6):80-84.LI H,CHEN L,PAN Q,et al.Research progress of heavy metal ecotoxicity diagnosis on rice.Environment and Sustainable Development,2013,37(6):80-84.(in Chinese with English abstract)

[5]LIU J,CAO C,WONG M,et al.Variations between rice cultivars in iron and manganese plaque on roots and the relation with plant cadmium uptake.Journal of Environmental Sciences,2010,22(7):1067-1072.

[6]SHAO G,CHEN M,WANG W,et al.Iron nutrition affects cadmium accumulation and toxicity in rice plants.Plant Growth Regulation,2007,53(1):33-42.

[7]CHIEN H F,WANG J W,LIN C C,et al.Cadmium toxicity of rice leaves is mediated through lipid peroxidation.Plant Growth Regulation,2001,33(3):205-213.

[8]白红红,章林平,王子民,等.锰对水稻亚铁毒害的缓解作用.中国水稻科学,2013,27(5):491-502.BAI H H,ZHANG L P,WANG Z M,et al.The ameliorative role of manganese on ferrous toxicity in rice plants.Chinese Journal of Rice Science,2013,27(5):491-502.(in Chinese with English abstract)

[9]周锋利,江玲,王松凤,等.钾离子对水稻亚铁毒害的缓解作用.南京农业大学学报,2006,28(4):6-10.ZHOU F L,JIANG L,WANG S F,et al.Amelioration of Fe2+toxicity by K+in rice.Journal of Nanjing Agricultural University,2005,28(4):6-10.(in Chinese withEnglish abstract)

[10]胡彬,祝金明,吴运荣,等.过氧化物酶在水稻亚铁毒害中的作用.浙江农业大学学报,1997,23(5):557-560.HU B,ZHU J M,WU Y R,et al.Effect of POD on tolerance to ferrous iron toxicity in rice.Journal of Zhejiang Agricultural University,1997,23(5):557-560.(in Chinese with English abstract)

[11]冯双华,贾凌辉,苏以荣.不同浓度亚铁培养液对水稻生长发育及产量构成的影响.农业现代化研究,1992,13(6):361-365.FENG S H,JIA L H,SU Y R.Different concentration of ferrous culture impact on rice growth and yield components.Research of Agricultural Modernization,1992,13(6):361-365.(in Chinese)

[12]刘侯俊,李雪平,韩晓日,等.铁镉互作对水稻脂质过氧化及抗氧化酶活性的影响.应用生态学报,2013,24(8):2179-2185.LIU H J,LI X P,HAN X R,et al.Effects of Fe-Cd interaction on the lipid peroxidation and antioxidative enzyme activities of rice.Chinese Journal of Applied Ecology,2013,24(8):2179-2185.(in Chinese with English abstract)

[13]黄益宗,朱永官,黄凤堂,等.镉和铁及其交互作用对植物生长的影响.生态环境,2004,13(3):406-409.HUANG Y Z,ZHU Y G,HUANG F T,et al.Effects of cadmium and iron and their interactions on plants growth:a review.Ecology and Environment,2004,13(3):406-409.(in Chinese with English abstract)

[14]Nakanishi H,Ogawa I,Ishimaru Y,et al.Iron deficiency enhances cadmium uptake and translocation mediated by the Fe2+transporters OsIRT1 and OsIRT2 in rice.Soil Science and Plant Nutrition,2006,52(4):464-469.

[15]邵胜国,MUHAMMAD J H,章秀福,等.镉胁迫对不同水稻基因型植株生长和抗氧化酶系统的影响.中国水稻科学,2004,18(3):239-244.SHAO S G,MUHAMMAD J H,ZHANG X F,et al.Effects of cadmium stress on plant growth and antioxidative enzyme system in different rice genotypes.Chinese Journal of Rice Science,2004,18(3):239-244.(in Chinese with English abstract)

[16]HOWELER R H.Iron-induced oranging disease of rice in relation to physico-chemical changes in a flooded oxisol.Soil Science Society of America Journal,1973,37(6):898-903.

[17]王贵民,陈国祥,杨艳华,等.亚铁对杂交水稻幼苗生长和部分生理生化特性的影响.南京师大学报(自然科学版),2003,26 (2):56-60.WANG G M,CHEN G X,YANG Y H,et al.Effects of EDTA-Fe2+on growth and physio-chemical characteristic of hybrid rice seedling.Journal of Nanjing Normal University (Natural Science),2003,26(2):56-60.(in Chinese with English abstract)

[18]邢承华,李方,徐根娣,等.铁毒胁迫对水稻幼苗中POD和CAT同工酶的影响.浙江农业学报,2008,20(6):457-460.XING C H,LI F,XU G D,et al.Effects of iron toxicity on POD and CAT isoenzymes in rice seedlings.Acta Agriculturae Zhejiangensis,2008,20(6):457-460.(in Chinese with English abstract)

[19]章秀福,王丹英,储开富,等.镉胁迫下水稻SOD活性和MDA含量的变化及其基因型差异.中国水稻科学,2006,20(2):194-198.ZHANG X F,WANG D Y,CHU K F,et al.Changes of SOD activity and MDA content in rice exposed to Cd stress as affected by genotype.Chinese Journal of Rice Science,2006,20(2):194-198.(in Chinese with English abstract)

[20]汪洪,赵士诚,夏文建,等.不同浓度镉胁迫对玉米幼苗光合作用,脂质过氧化和抗氧化酶活性的影响.植物营养与肥料学报,2008,14(1):36-42.WANG H,ZHAO S C,XIA W J,et al.Effect of cadmium stress on photosynthesis,lipid peroxidation and antioxidant enzyme activities in maize(Zea mays L.)seedlings.Plant Nutrition and Fertilizer Science,2008,14(1):36-42.(in Chinese with English abstract)

[21]张西科,张福锁,毛达如.根表铁氧化物胶膜对水稻吸收Zn的影响.应用生态学报,1996,7(3):262-266.ZHANG X K,ZHANG F S,MAO D R.Effect of root iron plaque on zinc uptake by rice.Chinese Journal of Applied Ecology,1996,7(3):262-266.(in Chinese with English abstract)

[22]ZHANG X,ZHANG F,MAO D.Effect of iron plaque outside roots on nutrient uptake by rice(Oryza sativa L.):phosphorus uptake.Plant and Soil,1999,209(2):187-192.

[23]胡莹,黄益宗,黄艳超,等.不同生育期水稻根表铁膜的形成及其对水稻吸收和转运Cd的影响.农业环境科学学报,2013,32(3):432-437.HU Y,HUANG Y Z,HUANG Y C,et al.Formation of iron plaque on root surface and its effect on Cd uptake and translocation by rice(Oryza sativa L.)at different growth stages.Journal of Agro-Environment Science,2013,32(3):432-437.(in Chinese with English abstract)

[24]史锟,张福锁,刘学军,等.不同栽培方式对籼,粳稻根表铁膜和根铁,镉含量的影响.应用生态学报,2003,14(8):1273-1277.SHI K,ZHANG F S,LIU X J,et al.Effect of different cultivation practices on Fe and Cd content in iron plaque outside rice root and Cd content in rice root.Chinese Journal of Applied Ecology,2003,14(8):1273-1277.(in Chinese with English abstract)

[25]HUANG Z,PAN X D,WU P G,et al.Health risk assessment of heavy metals in rice to the population in Zhejiang,China.PLoS ONE,2013,8(9):1-6.

[26]DU Y,HU X F,WU X H,et al.Affects of mining activities on Cd pollution to the paddy soils and rice grain in Hunan Province,Central South China.Environmental Monitoring and Assessment,2013,185(12):9843-9856.

[27]柴娟娟,廖敏,徐培智,等.我国主要低产水稻冷浸田养分障碍因子特征分析.水土保持学报,2012,26(2):284-288.CHAI J J,LIAO M,XU P Z,et al.Feature analysis on nutrient’s restrictive factors of major low productive waterlogged paddy soil in China.Journal of Soil and Water Conservation,2012,26(2):284-288.(in Chinese with English abstract)

[28]李合生.植物生理生化实验原理和技术.北京:高等教育出版社,1999,16:18-19.LI H S.Principle and Technology of Plant Physiological and Biochemical Experiments.Beijing:Higher Education Press,1999,16:18-19.(in Chinese)

[29]赵世杰,史国安,董新纯.植物生理学实验指导.北京:中国农业科学技术出版社,2002.ZHAO S J,SHI G A,DONG X C.Experiment Guidance on Plant Physiology.Beijing:China Agricultural Science and Technology Press,2002.(in Chinese)

[30]TAYLOR G J,CROWDER A A.Use of the DCB technique for extraction of hydrous iron oxides from roots of wetland plants.American Journal of Botany,1983:1254-1257.

[31]刘侯俊,胡向白,张俊伶,等.水稻根表铁膜吸附镉及植株吸收镉的动态.应用生态学报,2007,18(2):425-430.LIU H J,HU X B,ZHANG J L,et al.Dynam ics of Cd adsorption on rice seedlings root surface with iron coating and Cd uptake by plant.Chinese Journal of Applied Ecology,2007,18(2):425-430.(in Chinese with English abstract)

[32]刘文菊,张西科,张福锁.根表铁氧化物和缺铁根分泌物对水稻吸收镉的影响.土壤学报,1999,36(4):463-469.LIU W J,ZHANG X K,ZHANG F S.Effects of iron oxides and root exudates on cadmium uptake by rice.Acta Pedologica Sinica,1999,36(4):463-469.(in Chinese with English abstract)

[33]曹慧,韩振海,许雪峰,等.高等植物的铁营养.植物生理学通讯,2002,38(2):180-186.CAO H,HAN Z H,XU X F,et al.Iron nutrition in higher plants.Plant Physiology Journal,2002,38(2):180-186.(in Chinese)

[34]陈会,任艳芳,陈秀兰,等.镉胁迫下不同耐性水稻植株幼苗生长和抗氧化酶的变化.江西农业大学学报,2012,34(6):1099-1104.CHEN H,REN Y F,CHEN X L,et al.Changes of seedlings growth and antioxidant enzyme activities of different Cd-tolerant rice cultivars under cadmium stress.Acta Agriculturae Universitatis Jiangxiensis,2012,34(6):1099-1104.(in Chinese with English abstract)

[35]邵彩虹,谢金水,黄永兰,等.孕穗期水稻不同功能叶的发育蛋白质组学分析.中国水稻科学,2009(5):456-462.SHAO C H,XIE J S,HUANG Y L,et al.Developmental proteomics analysis of different functional leaves in rice(Oryza sativa)at the booting stage.Chinese Journal of Rice Science,2009(5):456-462.(in Chinese with English abstract)

[36]于方明,刘可慧,刘华,等.镉污染对水稻不同生育期抗氧化系统的影响.生态环境学报,2012(1):88-93.YU F M,LIU K H,LIU H,et al.Antioxidative responses to cadmium stress in the leaves of Oryza sativa L.in different growth period.Ecology and Environmental Sciences,2012(1):88-93.(in Chinese with English abstract)

[37]陈正刚,徐昌旭,朱青,等.不同类型冷浸田Fe2+对水稻生理酶活性的影响.中国农学通报,2014,30(12):63-70.CHEN Z G,XU C X,ZHU Q,et al.Effects of different types of cold water paddy field Fe2+on physiological activity of rice.Chinese Agricultural Science Bulletin,2014,30 (12):63-70.(in Chinese with English abstract)

[38]王永强,肖立中,李诗殷,等.铅镉复合污染对土壤和水稻叶片生理生化特性的影响.中国农学通报,2010,26(18):369-373.WANG Y Q,XIAO L Z,LI S Y,et al.Effects of compound pollution of Pb and Cd on soil and physiological and biochemistrical characteristics of rice leaves.Chinese Agricultural Science Bulletin,2010,26(18):369-373.(in Chinese with English abstract)

[39]方旭燕,俞慧娜,刘鹏,等.Fe2+对大豆幼苗生理特性的影响.生态环境,2006,15(2):341-344.FANG X Y,YU H N,LIU P,et al.Effect of Fe2+on physiological characteristics of soybean seedling.Ecology and Environment,2006,15(2):341-344.(in Chinese with English abstract)

[40]史锟,张福锁,刘学军,等.不同时期施铁对水稻根表铁胶膜中铁镉含量及根系含镉量的影响.农业环境科学学报,2004,23 (1):6-12.SHI K,ZHANG F S,LIU X J,et al.Effects of different periods applied Fe2+and concentrations on Fe and Cd contents in iron plaque on rice root.Journal of Agro-Environment Science,2004,23(1):6-12.(in Chinese with English abstract)

收稿日期(Received):2015-07-01;接受日期(Accepted):2015-09-10;网络出版日期(Published online):2016-01-19 URL:http://www.cnki.net/kcms/detail/33.1247.S.20160119.1940.016.html

*通信作者(

Corresponding author):杨京平(http://orcid.org/0000-0002-3212-0184),E-mail:jpyang@zju.edu.cn

基金项目:国家自然科学基金(61174089).

DOI:10.3785/j.issn.1008-9209.2015.07.011

中图分类号X 53;S 511

文献标志码A