苏云金芽胞杆菌对镉胁迫下水稻种苗生长发育的影响
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摘要
为探索苏云金芽胞杆菌(Bacillus thuringiensis,Bt)对重金属镉胁迫下水稻(Oryza sativa)种苗生长及生理生化指标的影响,本研究分别采用直接测量法、表观观察法和紫外分光光度法测定其对镉胁迫下水稻种苗苗高、根长、水稻种子发芽率、剑叶枯黄率与褐斑率以及叶绿素含量的影响。利用原子力显微镜观察镉处理前后的苏云金芽胞杆菌表面的变化。结果表明,经过镉处理的Bt菌的表面出现一些颗粒物,说明镉在细菌表面存在吸附的过程,暗示该菌在水稻田镉污染生物修复中具有潜在的应用前景。此外,在镉胁迫下,水稻种苗的生长受到抑制,其抑制作用随镉胁迫浓度的增大而增强。在50和400 mg/L Cd2+处理组中,根长与苗高的Cd处理与Cd+Bt处理的差异不显著(P>0.05),表明,镉胁迫下Bt菌处理的水稻种苗苗高和根长变化较小。在100和400 mg/L Cd2+处理组中,叶绿素a和叶绿素b的Cd+Bt处理较Cd处理显著提高(P<0.05);在200 mg/L Cd2+处理组中,Cd+Bt处理较Cd处理水稻种子发芽率显著提高(P<0.05)。施用Bt菌前后镉对水稻枯黄率与褐斑率的影响研究发现,50和400 mg/L Cd2+处理组中,Cd+Bt处理较Cd处理枯黄率显著下降(P<0.05);50 mg/L Cd2+处理组中未出现褐斑,400 mg/L Cd2+处理组中Cd+Bt处理较Cd处理褐斑率显著下降(P<0.05),表明,经Bt菌处理后水稻的剑叶枯黄率与褐斑率均低于未加菌的处理。本研究结果表明,Bt菌可以通过对重金属镉的吸附,减少水稻土中的游离镉的含量,从而减少了水稻种苗对重金属镉的吸附量,缓解镉对水稻的胁迫作用,并提高幼苗叶绿素的含量。本研究为Bt菌株在实际镉污染农田中的应用提供理论基础。
To study the effects of Bacillus thuringiensis on rice(Oryza sativa) seedling under cadmium stress,the plant growth parameters of germination rates of rice seeds, the yellow and brown rates of rice seedlings and chlorophyll content were determined by direct measurement method, apparent observation and ultraviolet spectrophotometry. Atomic force microscopy was applied to observe the surface changes of B. thuringiensis before and after cadmium treatment, and some granular dots were found on the bacterial surface, which implied there was surface adsorption of cadmium on B. thuringiensis, indicated that B. thuringiensis could be apotential bacterium in the practical applications of Cd2 +contaminated bioremediation on rice soil.Additionally, the growth of rice seedling was significantly inhibited under the cadmium stress, and the inhibition activity was enhanced with the increasing concentration of cadmium. However, the seedlings had no significant difference of shoot height and root length in 50 and 400 mg/L Cd2 +treatment groups between Cd and Cd+Bt groups(P>0.05), which indicated that there was no significant changes in the shoot height and root length of the seedlings before and after Bt treatment under the cadmium stress. The significant difference of chlorophyll a and b was found in 100 and 400 mg/L Cd2 +treatment between Cd and Cd+Bt groups(P<0.05). The rice seed germination rate had significant difference in 200 mg/L Cd2 +treatment group between Cd and Cd + Bt groups(P<0.05). Meanwhile, the yellow rate and brown spot rate of Cd + Bt and Cd treatments were also monitored. It was found that the yellow rates had significant difference in 50 and 400 mg/L Cd2 +treatment between Cd and Cd + Bt groups(P<0.05). In addition, the brown spot did not appear in the treatment group of 50 mg/L Cd2 +, while the brown spot rate had significant difference in 400 mg/L Cd2 +treatment between Cd and Cd+Bt groups(P<0.05), which indicated that both the yellow rate and brown spot rate of Cd + Bt were lower than the Cd treatment. The above results demonstrated that B. thuringiensis could reduce the concentration of free cadmium in rice soil by adsorption process, thereby relieve the cadmium stress and increase the chlorophyll content of rice seedlings. The present work provides a theoretical basis for the application of the Bt strain in the field of cadmium contamination.
To study the effects of Bacillus thuringiensis on rice(Oryza sativa) seedling under cadmium stress,the plant growth parameters of germination rates of rice seeds, the yellow and brown rates of rice seedlings and chlorophyll content were determined by direct measurement method, apparent observation and ultraviolet spectrophotometry. Atomic force microscopy was applied to observe the surface changes of B. thuringiensis before and after cadmium treatment, and some granular dots were found on the bacterial surface, which implied there was surface adsorption of cadmium on B. thuringiensis, indicated that B. thuringiensis could be apotential bacterium in the practical applications of Cd2 +contaminated bioremediation on rice soil.Additionally, the growth of rice seedling was significantly inhibited under the cadmium stress, and the inhibition activity was enhanced with the increasing concentration of cadmium. However, the seedlings had no significant difference of shoot height and root length in 50 and 400 mg/L Cd2 +treatment groups between Cd and Cd+Bt groups(P>0.05), which indicated that there was no significant changes in the shoot height and root length of the seedlings before and after Bt treatment under the cadmium stress. The significant difference of chlorophyll a and b was found in 100 and 400 mg/L Cd2 +treatment between Cd and Cd+Bt groups(P<0.05). The rice seed germination rate had significant difference in 200 mg/L Cd2 +treatment group between Cd and Cd + Bt groups(P<0.05). Meanwhile, the yellow rate and brown spot rate of Cd + Bt and Cd treatments were also monitored. It was found that the yellow rates had significant difference in 50 and 400 mg/L Cd2 +treatment between Cd and Cd + Bt groups(P<0.05). In addition, the brown spot did not appear in the treatment group of 50 mg/L Cd2 +, while the brown spot rate had significant difference in 400 mg/L Cd2 +treatment between Cd and Cd+Bt groups(P<0.05), which indicated that both the yellow rate and brown spot rate of Cd + Bt were lower than the Cd treatment. The above results demonstrated that B. thuringiensis could reduce the concentration of free cadmium in rice soil by adsorption process, thereby relieve the cadmium stress and increase the chlorophyll content of rice seedlings. The present work provides a theoretical basis for the application of the Bt strain in the field of cadmium contamination.
引文
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陈志,邹情雅,潘晓鸿,等.2014.铅锌矿尾矿坝分离节杆菌12-1对Pb2+的耐受和吸附性能研究[J].农业生物技术学报,22(11):1394-1401.(Chen Z,Zou Q Y,Pan X Het al.2014.Pb2+tolerance and adsorption of Arthrobacte sp.12-1 isolated from lead-zinc mine tailing dam[J]Journal of Agricultural Biotechnology,22(11):13941401.)
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李辉,闫萌,李丽丽,等.2010.蜡状芽孢杆菌SY的筛选、鉴定及对镉胁迫下水稻种子萌发的影响[J].安全与环境学报,10(5):11-14.(Li H,Yan M,Li L L,et al.2010Selection,identification of Bacillus cereus SY and its ef fects on the rice seed budding under cadmium stress[J]Journal of Safety and Environment,10(5):11-14.)
陆仲烟,宋正国,郭军康,等.2013.伯克氏菌对水稻种子萌发及初生幼苗耐镉性的影响[J].农业资源与环境学报,30(6):87-90.(Lu Z Y,Song Z G,Guo J K,et al2013.Effects of Burkholderia on rice seed germination and Cd-tolerance of rice seedlings[J].Journal of Agricul tural Resources and Environment,30(6):87-90.)
庞晓辰,王辉,吴泽嬴,等.2014.硒对水稻镉毒性的影响及其机制的研究[J].农业环境科学学报,33(9):16791685.(Pang X C,Wang H,Wu Z Y,et al.2014.Alleviation by selenium of cadmium toxicity to rice and it mechanisms[J].Journal of Agro-Environment Science33(9):1679-1685.)
宋伟,陈百明,刘琳.2013.中国耕地土壤重金属污染概况[J].水土保持研究,20(2):293-298.(Song W,Chen BM,Liu L.2013.Soil heavy metal pollution of cultivate land in China[J].Research of Soil and Water Conserva tion,20(2):293-298.)
孙岩,韩颖,李军,等.2013.硅对镉胁迫下水稻生物量及镉的化学形态的影响[J].西南农业学报,26(3):12401244.(Sun Y,Han Y,Li J,et al.2013.Effect of Si o rice biomass and chemical species of Cd under Cd stres[J].Southwest China Journal of Agricultural Sciences26(3):1240-1244.)
唐八生,杨怀兆.2013.复合菌剂对削减水稻镉吸收的生物技术研究[J].现代农业科技,(15):28-30.(Tang B S,Yan H Z.2013.Biotechnology research of compound bacteri um agent to cut rice cadmium absorption[J].Modern Ag ricultural Science and Technology,(15):28-30.)
王学奎,章文华,郝再彬,等.2006.植物生理生化实验原理和技术[M].高等教育出版社:134-136.(Wang X QZhang W H,Hao Z B,et al.2006.Principle and technol ogy of plant physiological and biochemical experiment[M].Higher Education Press,pp.134-136.)
杨居荣,久保井徹.1991.镉、铜对植物细胞的毒性及元素吸收特性的影响[J].环境科学学报,(3):381-386.(Yan J R,Kubo J C.1991.Effects of cadmium and copper o the toxicity of plant cells and the absorption of element[J].Journal of Environmental Science,(3):381-386.)
尹艺,赵颖,马莲菊,等.2014.碱蓬内生菌对镉胁迫水稻幼苗生长及生理生化指标的影响[J].贵州农业科学,4(3):23-26.(Yi Y,Zhao Y,Ma L J,et al.2014.Effects o endophyte isolated from Suaeda salsa on growth an physiological and biochemical indexes of rice seeding[J].Guizhou Agricultural Sciences,42(3):23-26.)
郑陶,李廷轩,张锡洲,等.2013.水稻镉高积累品种对镉的富集特性[J].中国农业科学,46(7):1492-1500.(ZhenT,Li Y X,Zhang X Z,et al.2013.Accumulation charac teristics of cadmium-accumulated rice cultivars with high cadmium accumulation[J].Scientia Agricultura Si nica,46(7):1492-1500.)
Alvarez M,Pennell R,Meijer P,et al.1998.Reactive oxygen intermediates mediate a systemic signal network in th establishment of plant immunity[J].Cell,92(6):773784.
Barrett J R.2012.A potential window onto early pancreati cancer development:Evidence of cancer stem cel growth after exposure to cadmium chloride in vitro[J]Environmental Health Perspect,120(9):1265-1271.
Cunningham S D,Ow D W.1996.Promise and prospects o phytoremediation[J].Plant Physiology,110(3):715-719.
Hayashi K,Tokida T,Hasegawa T.2011.Potential ammoni emission from flag leaves of paddy rice(Oryza sativa Lcv.Koshihikari)[J].Agriculture,Ecosystems&Environ ment,144(1):117-123.
Hossain A,Aditya G.2015.Biosorption of cadmium from aqueous solution by shell dust of the freshwater snai Melanoides tuberculata[J].Bioremediation Journal,19(4):80-91.
Ihsanullah,Al-Khaldi F A,Abusharkh B,et al.2015.Adsorptive removal of cadmium(Ⅱ)ions from liquid phase using acid modified carbon-based adsorbents[J].Journal of Molecular Liquids,204:255-263.
Pan X H,Cheng Y J,Pan D M.2014.Application of bacteria in remediation of Cr(Ⅵ)and Ni(Ⅱ)containing electroplating wastewater by cheap cultivation[J].Journal of Agricultural Biotechnology,22(6):779-786.
Qi X Z,Rui J Y,Lei L Y,et al.2015.Screening of lactic acid bacteria with potential protective effects against cadmium toxicity[J].Food Control,54:23-30.
Raskin I I,Smith R D,Salt D E,et al.1997.Phytoremediation of metals:Using plants to remove pollutants from the environment[J].Current Opinion in Biotechnology,8(2):221-226.
曹霞.2009.耐铅镉微生物的筛选及其对污染土壤铅镉化学形态的影响[D].硕士学位论文,华中农业大学,导师谭启玲,pp.14.(Cao X.2009.Lead and cadmium resis tance screening of microorganisms and their effects on lead and cadmium contaminated soil chemical form[D]Thesis for M.S.,Huazhong Agricultural University,Su pervisor:Tan Q L,pp.14.)
陈志,邹情雅,潘晓鸿,等.2014.铅锌矿尾矿坝分离节杆菌12-1对Pb2+的耐受和吸附性能研究[J].农业生物技术学报,22(11):1394-1401.(Chen Z,Zou Q Y,Pan X Het al.2014.Pb2+tolerance and adsorption of Arthrobacte sp.12-1 isolated from lead-zinc mine tailing dam[J]Journal of Agricultural Biotechnology,22(11):13941401.)
傅华新,林鸿权.1995.镉化合物的发展及其开发应用[J].湘潭化工,24(2):8-10.(Fu H X,Lin H Q.1995.The de velopment of cadmium compounds and its developmen and application[J].Xiangtan Chemical Industry,24(2)8-10.)
李辉,闫萌,李丽丽,等.2010.蜡状芽孢杆菌SY的筛选、鉴定及对镉胁迫下水稻种子萌发的影响[J].安全与环境学报,10(5):11-14.(Li H,Yan M,Li L L,et al.2010Selection,identification of Bacillus cereus SY and its ef fects on the rice seed budding under cadmium stress[J]Journal of Safety and Environment,10(5):11-14.)
陆仲烟,宋正国,郭军康,等.2013.伯克氏菌对水稻种子萌发及初生幼苗耐镉性的影响[J].农业资源与环境学报,30(6):87-90.(Lu Z Y,Song Z G,Guo J K,et al2013.Effects of Burkholderia on rice seed germination and Cd-tolerance of rice seedlings[J].Journal of Agricul tural Resources and Environment,30(6):87-90.)
庞晓辰,王辉,吴泽嬴,等.2014.硒对水稻镉毒性的影响及其机制的研究[J].农业环境科学学报,33(9):16791685.(Pang X C,Wang H,Wu Z Y,et al.2014.Alleviation by selenium of cadmium toxicity to rice and it mechanisms[J].Journal of Agro-Environment Science33(9):1679-1685.)
宋伟,陈百明,刘琳.2013.中国耕地土壤重金属污染概况[J].水土保持研究,20(2):293-298.(Song W,Chen BM,Liu L.2013.Soil heavy metal pollution of cultivate land in China[J].Research of Soil and Water Conserva tion,20(2):293-298.)
孙岩,韩颖,李军,等.2013.硅对镉胁迫下水稻生物量及镉的化学形态的影响[J].西南农业学报,26(3):12401244.(Sun Y,Han Y,Li J,et al.2013.Effect of Si o rice biomass and chemical species of Cd under Cd stres[J].Southwest China Journal of Agricultural Sciences26(3):1240-1244.)
唐八生,杨怀兆.2013.复合菌剂对削减水稻镉吸收的生物技术研究[J].现代农业科技,(15):28-30.(Tang B S,Yan H Z.2013.Biotechnology research of compound bacteri um agent to cut rice cadmium absorption[J].Modern Ag ricultural Science and Technology,(15):28-30.)
王学奎,章文华,郝再彬,等.2006.植物生理生化实验原理和技术[M].高等教育出版社:134-136.(Wang X QZhang W H,Hao Z B,et al.2006.Principle and technol ogy of plant physiological and biochemical experiment[M].Higher Education Press,pp.134-136.)
杨居荣,久保井徹.1991.镉、铜对植物细胞的毒性及元素吸收特性的影响[J].环境科学学报,(3):381-386.(Yan J R,Kubo J C.1991.Effects of cadmium and copper o the toxicity of plant cells and the absorption of element[J].Journal of Environmental Science,(3):381-386.)
尹艺,赵颖,马莲菊,等.2014.碱蓬内生菌对镉胁迫水稻幼苗生长及生理生化指标的影响[J].贵州农业科学,4(3):23-26.(Yi Y,Zhao Y,Ma L J,et al.2014.Effects o endophyte isolated from Suaeda salsa on growth an physiological and biochemical indexes of rice seeding[J].Guizhou Agricultural Sciences,42(3):23-26.)
郑陶,李廷轩,张锡洲,等.2013.水稻镉高积累品种对镉的富集特性[J].中国农业科学,46(7):1492-1500.(ZhenT,Li Y X,Zhang X Z,et al.2013.Accumulation charac teristics of cadmium-accumulated rice cultivars with high cadmium accumulation[J].Scientia Agricultura Si nica,46(7):1492-1500.)
Alvarez M,Pennell R,Meijer P,et al.1998.Reactive oxygen intermediates mediate a systemic signal network in th establishment of plant immunity[J].Cell,92(6):773784.
Barrett J R.2012.A potential window onto early pancreati cancer development:Evidence of cancer stem cel growth after exposure to cadmium chloride in vitro[J]Environmental Health Perspect,120(9):1265-1271.
Cunningham S D,Ow D W.1996.Promise and prospects o phytoremediation[J].Plant Physiology,110(3):715-719.
Hayashi K,Tokida T,Hasegawa T.2011.Potential ammoni emission from flag leaves of paddy rice(Oryza sativa Lcv.Koshihikari)[J].Agriculture,Ecosystems&Environ ment,144(1):117-123.
Hossain A,Aditya G.2015.Biosorption of cadmium from aqueous solution by shell dust of the freshwater snai Melanoides tuberculata[J].Bioremediation Journal,19(4):80-91.
Ihsanullah,Al-Khaldi F A,Abusharkh B,et al.2015.Adsorptive removal of cadmium(Ⅱ)ions from liquid phase using acid modified carbon-based adsorbents[J].Journal of Molecular Liquids,204:255-263.
Pan X H,Cheng Y J,Pan D M.2014.Application of bacteria in remediation of Cr(Ⅵ)and Ni(Ⅱ)containing electroplating wastewater by cheap cultivation[J].Journal of Agricultural Biotechnology,22(6):779-786.
Qi X Z,Rui J Y,Lei L Y,et al.2015.Screening of lactic acid bacteria with potential protective effects against cadmium toxicity[J].Food Control,54:23-30.
Raskin I I,Smith R D,Salt D E,et al.1997.Phytoremediation of metals:Using plants to remove pollutants from the environment[J].Current Opinion in Biotechnology,8(2):221-226.