全 文 : [收稿日期]2014 04 18
[基金项目]湖北省教育厅科学研究项目 (B20101301)。
[作者简介]瞿静 (1982 ),女,助教,主要从事园林植物栽培研究。
[通讯作者]吴楚,E-mail:wuchuchu2001@126.com。
重金属胁迫下外源钛铁试剂对冬珊瑚幼苗根系发
育、生物量累积及其分配格局的影响
瞿静,吴楚 (长江大学园艺园林学院,湖北 荆州434025)
[摘要]汞 (Hg)可抑制植物的生长发育,对植物具有明显的毒害作用。探讨了不同浓度的钛铁试剂
(Tiron)对汞胁迫下的冬珊瑚 (Solanum pseudocapsicum)幼苗根系生长、生物量累积及其分配的影响。
结果表明:加入5μmol·L
-1 钛铁试剂后,冬珊瑚幼苗总根长、总投影面积、总表面积比对照增加;随着
外加钛铁试剂浓度的升高,总根长、总表面积和总投影面积呈现逐渐降低的变化趋势,根系体积随钛铁
试剂处理浓度增加而增加;根系根尖数随着钛铁试剂处理浓度的增加而减少,表明钛铁试剂对 Hg毒性的
缓解作用随着钛铁试剂浓度的升高而减弱,高浓度的钛铁试剂对植物表现出毒害作用。无论钛铁试剂的
处理浓度如何,冬珊瑚异速生长指数都小于1,这表明在冬珊瑚幼苗阶段,生长偏向于地上部分。随着外
加钛铁试剂浓度的升高,异速生长指数随着浓度的增加而增大,这表明随着外源钛铁试剂的浓度增加,
植物生物量的分配越向地下分配。
[关键词]钛铁试剂;冬珊瑚 (Solanum pseudocapsicum);重金属胁迫;根生长;生物量分配
[中图分类号]Q945.78 [文献标识码]A [文章编号]1673 1409 (2014)23 0055 05
自然界存在的90种元素中,有53种重金属 (包括 As在内),然而只有少数几种具有生理作用,
为植物所必需的微量营养元素,如Cr、Mo和Co,但如果这些元素过量,则对植物产生有害影响。另
外一些重金属元素,如Pb、Hg和Cd,它们对植物没有生理作用,而对植物产生有害影响[1-2]。这些影
响包括水分关系[3]、光合作用与其他生理特性[4-9]、植物生长发育[10-12]。重金属对植物的有害影响与其
引起的氧化胁迫有关[2,13-15]。因此,如何有效及时消除因重金属引起的氧自由基而保护植物,成为植物
修复和促进植物生长发育的一个重要途径。
植物细胞含有各种抗氧化剂,如抗坏血酸、谷胱苷肽、α-生育酚以及各种酚类化合物。这些化合物
协同抗氧化酶在清除氧自由基减缓氧化胁迫方面起着重要的作用。如果采用外源试剂,则能更好地清除
氧自由基。钛铁试剂 (Tiron,disodium 1,2-dihydroxybenzene-3,5-disulfonate)是一种水溶性的非毒
性的自由基清除剂,可以透过细胞膜而起作用[16]。本研究试图利用钛铁试剂缓解重金属汞对常见栽培
花卉冬珊瑚 (Solanum pseudocapsicum)产生的有害影响,对其在根系发育和生物量分配方面进行初
步研究,以为其在受到重金属污染的土地上恢复植被并促进植物生长发育提供参考。
1 材料与方法
1.1 试验材料培养
冬珊瑚种子采自长江大学植物园。将河沙清洗干净,然后装入塑料盆中 (直径15cm,高15cm),
将事先催芽的冬珊瑚种子均匀播种于河沙表面,然后以洗净的河沙覆盖。待种子萌发、幼苗长到3片真
叶时,移植到装有1.5kg土壤 (未经污染的园土)的塑料盆内 (直径15cm,高15cm)中,每盆5株幼
苗,自然光照培养。
1.2 氯化汞和钛铁试剂处理
将冬珊瑚幼苗移植于温室大棚中,培养20d后,每盆灌入等量的氯化汞溶液 (100ml 5g·L-1)。
·55·
长江大学学报 (自然科学版) 2014年8月号农学中旬刊 第11卷 第23期
Journal of Yangtze University(Nat Sci Edit) Aug.2014,Vol.11No.23
DOI:10.16772/j.cnki.1673-1409.2014.23.010
2d后喷洒不同浓度的钛铁试剂:0 (T0)、5(T1)、10(T2)、20μmol·L
-1 (T3)。自然条件下培养,
每隔5d用0、5、10、20μmol·L
-1 的钛铁试剂溶液分别进行处理。35d后取样,测定各项指标。
1.3 根系分析
先把冬珊瑚苗木从塑料桶中小心地取出,保持根系完整,从根颈部位将幼苗分成地上和地下两部
分,地下部分用水浸泡,洗净冬珊瑚苗木根系上面残留的泥土,使用 WinRhizo根系分析系统对根系进
行扫描和分析,取得总根长、总表面积、总投影面积、总体积以及根尖数等参数。在75℃下烘至衡重
后用分析天平称量。
1.4 异速生长分析
异速生长分析按照吴楚等[17] 的方法进行。
lg Wr=a+Klg Ws
式中,Wr和Ws分别是根干重和地上部分的干重,K为异速生长常数。
1.5 统计分析
利用SPSS V10.0软件进行统计分析,以P<0.05为标准判断各处理之间的差异显著性。
2 结果与分析
2.1 不同钛铁试剂浓度对汞胁迫下冬珊瑚幼苗根系发育的影响
图1A结果表明,T1 处理下,冬珊瑚幼苗根系根长比对照 T0 增加,差异性不显著 (P>0.05,
LSD);从T2至T3,冬珊瑚幼苗根系根长逐渐下降,但只有T0 与T3 之间存在显著差异 (P<0.05,
LSD)。总表面积和总投影面积的变化趋势与总根长度的变化趋势相似 (图1B)。不同钛铁试剂浓度对
汞胁迫下冬珊瑚幼苗根系总体积具有很重大的影响。总体上,根系体积随钛铁试剂处理浓度增加而增加
图1 汞胁迫下钛铁试剂对冬珊瑚幼苗根系形态参数的影响
·65· 农学中旬刊*环境科学 2014年8月
(图1C)。T0、T12种浓度处理之间无显著差异,但它们与T3 之间存在显著差异 (P<0.05,LSD)。
同时,T2 处理与T3 处理差异显著 (P<0.05,LSD)。
不同钛铁试剂浓度对汞胁迫下冬珊瑚幼苗根系根尖数具有较大的影响。T1 处理下,冬珊瑚幼苗根
系根尖数显著多于对照T0 (P<0.05,LSD,图1D);随着外加钛铁试剂浓度的升高,根系根尖数随
着浓度的增加而减少。在T2 或T3 处理下,冬珊瑚幼苗根系根尖数比T0 增加,差异性不显著 (P>
0.05,LSD);整个根系的根尖数量在T1 时达到最大,与其他几种处理存在显著差异。
图2 汞胁迫下钛铁试剂对冬珊瑚幼苗生物量累积的影响
2.2 不同钛铁试剂浓度对汞胁迫下冬珊瑚幼苗生物量累积和异速生长的影响
钛铁试剂处理对冬珊瑚幼苗总
生物量的累积以及地上部分和地下
部分生物量没有显著的影响 (图
2)。不同钛铁试剂浓度对汞胁迫下
冬珊瑚幼苗异速生长具有影响 (图
3)。异速生长分析建立在根系生物
量 (Wr)和地上部分生物量 (Ws)
的对数之间的直线关系的基础上,
其直线关系的斜率即为异速生长指
数。从图3可以看出,无论钛铁试
剂的处理浓度如何,异速生长指数
都小于1,这表明在冬珊瑚幼苗阶
段,生长偏向于地上部分,因此,
图3 汞胁迫下钛铁试剂对冬珊瑚幼苗生物量分配格局的影响
·75·第11卷 第23期 瞿静等:重金属胁迫下外源钛铁试剂对冬珊瑚幼苗根系发育、生物量累积及其分配格局的影响
这种生长特性引起生物量分配偏向于地上分配。随着外加钛铁试剂浓度的升高,异速生长指数随着浓度
的增加而增大,这表明随着外源钛铁试剂的浓度增加,植物生物量的分配越向地下分配。
3 讨论与结论
3.1 讨论
3.1.1 钛铁试剂对汞胁迫下冬珊瑚幼苗根系的影响
汞是一种植物非必需元素,在植物体内积累到一定程度,可能对植物造成毒害[18-19]。汞是环境中的
有毒重金属,能够影响植物细胞的正常分裂,导致膜脂过氧化水平提高,细胞超微结构发生变化,抑制
植物的生长发育,对植物具有明显的毒害作用[20-22]。本研究中,5g·L-1 的汞添加量对冬珊瑚幼苗的生
长产生了毒害作用。
钛铁试剂是一种高效无毒的膜渗透性外源自由基清除剂[16],能透过细胞膜,可以清除细胞内的自
由基。适当与适量的钛铁试剂能提高植物抗重金属污染胁迫的能力。植物的根是植物长期适应陆上生活
而发展起来的一种向下生长的器官。植物通过根系和外界土壤中的物质进行交流。根系是植物吸收养分
的主要器官,根的活力水平直接影响地上部分的生长和营养状况及产量水平,外源重金属进入土壤后,
根是植物体中最重要的结合重金属的部位,也是最易受重金属毒性影响的部位。重金属能抑制根尖细胞
核的分裂,根长的变化是一个重要的指示植物受重金属毒性影响的指标[23]。本研究中,加
入5μmol·L
-1 钛铁试剂后,冬珊瑚幼苗总根长、总投影面积、总表面积增加,并达到最大值,说明
5μmol·L
-1 的钛铁试剂可以在一定程度上缓解 Hg对冬珊瑚幼苗造成的毒害。钛铁试剂和汞的联合作
用可以缓解重金属汞对冬珊瑚幼苗根系的伤害。这种缓解作用随着外加钛铁试剂浓度的升高而呈现逐渐
减弱的趋势,高浓度钛铁反而使冬珊瑚幼苗总根长、总投影面积、总表面积和根尖数下降,可能是高浓
度钛铁试剂对植物产生了毒害作用。该结果与袁宇飞等[24] 用锌处理汞胁迫下小麦幼苗的研究结果类
似。
3.1.2 钛铁试剂对汞胁迫下冬珊瑚幼苗异速生长的影响
无论钛铁试剂的处理浓度如何,冬珊瑚幼苗的根系的异速生长指数都小于1 (图3),这表明冬珊瑚
在幼苗期间,生物量的分配都倾向于地上部分。随着外加钛铁浓度的升高,异速生长指数K随着浓度
的增加而增大。由此可知,钛铁试剂对汞胁迫下的冬珊瑚幼苗生物量分配格局产生了重大作用。这可能
与植物根系对汞胁迫的反应有关,而植物对汞胁迫的反应与植物生长素的再分配有关。因此,在外加钛
铁试剂的条件下,汞胁迫下的冬珊瑚幼苗根系发育受到生长素再分配的影响较大,从而导致生物量向地
上部分的分配超过了向地下部分的分配。
3.2 结论
0~5μmol·L
-1 Tiron可以在一定程度上缓解汞对冬珊瑚幼苗造成的毒害,因此,对于单一重金属
汞污染,可以通过适当调节钛铁试剂的加入水平来提高修复汞污染的效率。但是高浓度的钛铁试剂会对
植物产生毒害。
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·95·第11卷 第23期 瞿静等:重金属胁迫下外源钛铁试剂对冬珊瑚幼苗根系发育、生物量累积及其分配格局的影响
protein V and W derived from different virulence NDV strain can induce early cel apop-
tosis,but they have different ability to induce cel apoptosis.
Key words:newcastle disease virus;V gene;W gene;eukaryotic expression;apoptosi
042Effect of Germination and Fermentation on Phytase Activity of Wheat
CAO Zhi-hua,LUO Jing-bo (College of Animal Science,Yangtze University,Jingzhou,Hubei 434025,China)
Abstract:In order to study the effect of germination and fermentation on the activity of
phytase in wheat,the process of germination and fermentation lasts for 0to 6days and
the activity of phytase is tested daily.The results showed that germination significantly
improve the activity of phytase in the seeds of wheats.Compared with the activity of
phytase in the wheats that haven’t germinated and that have been germinated for 1day,
the activity of phytase is significantly different and reached highest in the three kinds of
wheats that have germinated for 3days and reached 2120,2350,2890U/kg respectively.
Besides,fermentation also significantly improve the activity of phytase in wheat seeds.
Compared with the activity of phytase in the wheats that haven’t fermented and that
have been fermented for 1day,the activity of phytase has been significantly different and
reached highest in the three kinds of wheats that have been fermented for 3days or 4
days and reached 2110,2026,2180U/kg respectively.
Key words:activity of phytase;fermentation;germination;wheat
045Avian Resources on the Campus of Yangtze University
LI Shao-bin,LI Chong-mou (College of Life Science,Yangtze University,Jingzhou,Hubei 434025,China)
Abstract:Fieldwork was carried out on the campus of Yangtze University between July
2013and March 2014.Transect method was repeatedly used to survey the bird diversity
on the campus.During the investigations,89bird species from 13orders and 34families
were recorded.Among the species surveyed,40species were residents,19species sum-
mer visitors,29species winter visitors and 1passing migrant.49species breed in this ar-
ea and constituted the main body of avian fauna on the campus.Fauna analysis reveals
that Palaearctic species were the dominant ones(41species,46.1%),Oriental species
second(28species,31.5%),while the widespread species are least(20species,22.5%).
Among the recorded species,10species(11.2%)were listed as national second-grade
protected wildlife in China,71species(79.8%)as“useful or important species to econo-
my and scientific research”and 26species(29.2%)as the key protected species of Hu-
bei province.Three Chinese endemic bird species were also distributed there.On the in-
ternational scale,7species of this fauna were listed in CITESⅡand 1species in IUCN
red list(Near threatened).Among the categories of habitats on the campus,bird diversi-
ty was richest in woodlands while the least was in residential areas.It indicated that hu-
man activities significantly affect the avian fauna.
Key words:wildlife;avifauna;resource survey;ecological distribution;Yangtze University
055Effects of Tiron on Root Development,Biomass Accumulation and Alocation of Solanum
pseudocapsicumSeedlings under Heavy Metal Stress
QUJing,WU Chu (College of Horticulture and Gardening,Yangtze University,Jingzhou,Hubei 434025,China)
Abstract:Mercury is toxic to plants and inhibits growth and development of plants.In or-
der to provide base for practical use of Tiron in phytomediation of land the effects of
Tiron on root growth,biomass accumulation and alocation of Solanum pseudocapsicum
seedlings under mercury stress were studied.The results showed that under heavy metal
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stress the treatment of treatment 5μmol·L
-1 increased total root length,project area
and total root surface area.But as the concentrations of Tiron increased,the three param-
eters decreased,total root volume and root tips increased.Under al treatments of Tiron,
alometric index were less than 1,suggesting biomass alocation is prone to shoots.But as
concentrations of Tiron increased,alometric index increased,suggesting Tiron treatment
could increase biomass alocation to roots.
Key words:Tiron;Solanum pseudocapsicum;heavy metal stress;root growth;biomass al-
location
060Optimizing Extract Conditions of Tea Polysaccharides with Ultrasonic by Using Response
Surface Methodology
TAO A-li,YU Da-qun (College of Pharmaceutical Sciences,Anhui Xinhua University,Hefei,Anhui 230088,China)
Abstract:Aiming at the determination of the contents of tea polyphenols,with water as
the extraction of the polyphenols in Huangshan Maofeng tea with ultrasonic method,the
extraction time,solid-liquid ratio,extraction times on the extraction rate of tea polyphe-
nols were investigated.On the basis of single factor,by central composite design of Box-
Behnken through the analysis of the experimental optimization,the optimum conditions
of extraction response surface,the results further confirmed that the optimized extraction
conditions for the extraction time was 40.99min,ratio of material to liquid(g/ml)was 1
∶31.84,extracting 3times,and the constraction ratio can reach 21.91%.
Key words:tea polyphenols;ultrasonic;single factor;response surface methodology
065Studies on Centrifugal Ginseng Microtome Machine
CHEN Yi-hou (College of Mechanical Engineering,Yangtze University,Jingzhou,Hubei 434023,China)
Abstract:The structure,working principles of the centrifugal ginseng microtome machine
were introduced.The key parameter was optimum-seeking designed.It provided design
basis for the manufacture of the machince of the the centrifugal ginseng microtome.
Key words:the centrifugal ginseng microtome machine;structure;design
068Planning of Soil Improvement in Japanese Farmland Construction Planning
PAN Chuan-bai Water Conservancy and Hydropower Survey and Design Institute of Jingzhou City
,
Hubei Province,Jingzhou,Hubei 434000,China( )
YANG Meng-yun (Nanjing Minghui Construction Co.Ltd,Nanjing,Jiangsu 210000,China)
Abstract:The aim of the planning of soil improvement in Japan is to keep the effective
soil,realize large scale operation of land use to determine the exploitable type of agricul-
ture.To achieve this objective,the soil improvement in Japan is conducted comprehen-
sively from the respects of the effective soil layer,soil permeability,soil bearing capacity,
field surface flatness.The results,based on soil survey,show that the soil improving
methods of banking up manure,treating soil surface,supplementing organic matter in the
soil to improve the soil,and the construction to change soil permeability,the soil testing
method,the way to improve the soil bearing capacity,the measure of field leveling have a
certain reference value in Chinese soil improvement.
Key words:Japan;irrigation and water conservancy;soil improvement;planning;design
Translated &Edited by YANG Xian-ming(杨先明)
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