小麦幼苗根系形态对镉胁迫的响应
|
摘要
为了研究镉(Cd)在小麦体内的吸收、转运过程,以及Cd对小麦根系形态的影响,本文通过水培试验分析了小麦在5种Cd水平下(0、0.5、5、50、200μmol·L~(-1))处理3、6、11、17 d和23 d后各项生长指标的变化,并用荧光显微镜观察了Cd处理17 d后小麦根系形态的变化情况。结果表明,小麦幼苗对Cd的吸收能力与Cd浓度成反比关系,且在Cd0.5处理下,小麦对Cd的吸收和转运的能力显著高于其他处理。随着Cd处理浓度的增加,小麦幼苗的生物量、株高、总根长、根体积、总根尖数目逐渐减小,根系平均直径逐渐增加。相关性分析结果表明,小麦幼苗对Cd的吸收能力与平均直径呈显著正相关,对Cd的转运能力仅与平均直径呈显著负相关。进一步通过荧光显微镜观察,结果显示Cd处理可诱导小麦幼苗根系皮层细胞增多、薄壁细胞增大以及内皮层细胞壁木质素的沉积。Cd诱导的根系直径增粗对小麦Cd的吸收及转运都起着非常重要的作用。
The current study is aimed at investigating the absorption and transport processes of cadmium(Cd)in wheat, and changes in wheat root morphology, in response to Cd treatment. A hydroponic experiment was conducted to investigate the effect of different Cd concentrations(0, 0.5, 5, 50, and 200 μmol·L~(-1))on wheat seedling growth and root morphology. Wheat growth was measured after 3, 6, 11,17, and 23 d of Cd treatment, and root morphology was determined after 17 d of treatment. The results demonstrated the presence of a negative correlation between Cd uptake ability and the Cd concentration in wheat, and that maximum absorption and transport abilities were found under Cd0.5 treatment. With increased Cd treatment concentration, wheat seedling biomass, plant height, total root length, root volume, and numbers of total root tips decreased gradually, while root average diameter increased significantly. Correlation analysis showed that seedling Cd uptake ability was positively correlated, while transport capacity was negatively related, with average root diameter. Further observation by fluorescence microscopy showed that Cd treatment could induce increased root cortical cell numbers, enlargement of parenchyma cells, and deposition of lignin in endodermal cell walls. Cd-induced increase in average root diameter may play an important role in Cd absorption and transportation in wheat.
The current study is aimed at investigating the absorption and transport processes of cadmium(Cd)in wheat, and changes in wheat root morphology, in response to Cd treatment. A hydroponic experiment was conducted to investigate the effect of different Cd concentrations(0, 0.5, 5, 50, and 200 μmol·L~(-1))on wheat seedling growth and root morphology. Wheat growth was measured after 3, 6, 11,17, and 23 d of Cd treatment, and root morphology was determined after 17 d of treatment. The results demonstrated the presence of a negative correlation between Cd uptake ability and the Cd concentration in wheat, and that maximum absorption and transport abilities were found under Cd0.5 treatment. With increased Cd treatment concentration, wheat seedling biomass, plant height, total root length, root volume, and numbers of total root tips decreased gradually, while root average diameter increased significantly. Correlation analysis showed that seedling Cd uptake ability was positively correlated, while transport capacity was negatively related, with average root diameter. Further observation by fluorescence microscopy showed that Cd treatment could induce increased root cortical cell numbers, enlargement of parenchyma cells, and deposition of lignin in endodermal cell walls. Cd-induced increase in average root diameter may play an important role in Cd absorption and transportation in wheat.
引文
[1]Zhang X F,Gao B,Xia H P.Effect of cadmium on growth,photosynthesis,mineral nutrition and metal accumulation of bana grass and vetiver grass[J].Ecotoxicology&Environmental Safety,2014,106:102-108.
[2]Ali H,Khan E,Sajad M A.Phytoremediation of heavy metals:Concepts and applications[J].Chemosphere,2013,91(7):869-881.
[3]Uraguchi S,Maori S,Kuramata M,et al.Root-to-shoot Cd translocation via the xylem is the major process determining shoot and grain cadmium accumulation in rice[J].Journal of Experimental Botany,2009,60(9):2677-2690.
[4]滕振宁,方宝华,刘洋,等.镉对不同品种水稻光合作用的影响[J].中国农业气象,2016,37(5):538-544.TENG Zhen-ning,FANG Bao-hua,LIU Yang,et al.Effect of cadmium on photosynthesis of different rice varieties[J].Chinese Journal of Agrometeorology,2016,37(5):538-544.
[5]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.
[6]邓丹.根系结构对水稻吸收砷的影响[D].上海:华东师范大学,2009.DENG Dan.Effect of root structure on absorption of arsenic in rice[D].Shanghai:East China Normal University,2009.
[7]李天哲,陈爱婷,李彩,等.镉胁迫下硅对水稻幼苗生长与生理响应的影响[J].农业环境科学学报,2018,37(6):1072-1078.LI Tian-zhe,CHEN Ai-ting,LI Cai,et al.Effects of silicon on the growth and physiological responses of rice seedlings under cadmium stress[J].Journal of Agro-Environment Science,2018,37(6):1072-1078.
[8]李君,葛跃,王明新,等.镉对蓖麻耐性生理及营养元素吸收转运的影响[J].环境科学学报,2016,36(8):3081-3087.LI Jun,GE Yue,WANG Ming-xin,et al.Effects of cadmium on the physiological and nutrient elements absorption and translocation of ramie[J].Acta Scientiae Circumstantiae,2016,36(8):3081-3087.
[9]Zhao F Y,Han M M,Zhang S Y,et al.Hydrogen peroxide-mediated growth of the root system occurs via auxin signaling modification and variations in the expression of cell-cycle genes in rice seedlings exposed to cadmium stress[J].Journal of Integrative Plant Biology,2012,54(12):991-1006.
[10]张欣,王华忠,王利,等.不同品种小麦幼苗耐镉差异[J].江苏农业科学,2018,46(7):61-65.ZHANG Xin,WANG Hua-zhong,WANG Li,et al.Differences in cadmium tolerance between different wheat varieties[J].Jiangsu Agricultural Sciences,2018,46(7):61-65.
[11]Zhang X F,Zhang X H,Gao B,et al.Effect of cadmium on growth,photosynthesis,mineral nutrition and metal accumulation of an energy crop,king grass(Pennisetum americanum×P.purpureum)[J].Biomass&Bioenergy,2014,67:179-187.
[12]冯汉青,杜变变,王庆文,等.镉胁迫下活性炭对小麦幼根的保护作用[J].生态学报,2016,36(10):2962-2968.FENG Han-qing,DU Bian-bian,WANG Qing-wen,et al.Protective effect of activated carbon on young roots of wheat under cadmium stress[J].Acta Ecologica Sinica,2016,36(10):2962-2968.
[13]Malamy J.Intrinsic and environmental response pathways that regulate root system architecture[J].Plant,Cell and Environment,2005,28:67-77.
[14]王艺霖,周玫,李苹,等.根系形态可塑性决定黄栌幼苗在瘠薄土壤中的适应对策[J].北京林业大学学报,2017,39(6):60-69.WANG Yi-lin,ZHOU Mei,LI Ping,et al.Root morphological plasticity determines the adaptation strategies of Astragalus seedlings in infertile soil[J].Journal of Beijing Forestry University,2017,39(6):60-69.
[15]陈杰,许长征,曹颖倩,等.不同重金属对拟南芥根系特征的影响比较[J].应用与环境生物学报,2017,23(6):1122-1128.CHEN Jie,XU Chang-zheng,CAO Ying-qian,et al.Comparison of the effects of different heavy metals on the root characteristics of Arabidopsis thaliana[J].Chinese Journal of Applied&Environmental Biology,2017,23(6):1122-1128.
[16]Lux A,Martinka M,Vaculík M,et al.Root responses to cadmium in the rhizosphere:A review[J].Journal of Experimental Botany,2011,62(1):21-37.
[17]VaculíM,Konlechner C,Langer I,et al.Root anatomy and element distribution vary between two Salix caprea isolates with different Cd accumulation capacities[J].Environmental Pollution,2012,163(1):117-126.
[18]Lux A,SottníkováA,OpatrnáJ,et al.Differences in structure of adventitious roots in Salix clones with contrasting characteristics of cadmium accumulation and sensitivity[J].Physiol Plant,2010,120(4):537-545.
[19]Ostonen I,Püttseppü,Biel C,et al.Specific root length as an indicator of environmental change[J].Giornale Botanico Italiano,2007,141(3):426-442.
[20]Lu Z,Zhang Z,Su Y,et al.Cultivar variation in morphological response of peanut roots to cadmium stress and its relation to cadmium accumulation[J].Ecotoxicology&Environmental Safety,2013,91(4):147-155.
[21]姜涛.铝胁迫对饭豆根尖营养元素吸收的影响及可能的调控机制[D].杭州:浙江大学,2013.JIANG Tao.Effects of aluminum stress on nutrient absorption of root tips of rice bean and its possible regulation mechanism[D].Hangzhou:Zhejiang University,2013.
[22]张苏波.不同水稻品种吸收重金属特点研究[D].扬州:扬州大学,2016.ZHANG Su-bo.Characteristics of absorption of heavy metals in different rice varieties[D].Yangzhou:Yangzhou University,2016.
[23]Gao W,Nan T,Tan G,et al.Cellular and subcellular immunohistochemical localization and quantification of cadmium ions in wheat(Triticum aestivum)[J].PLoS One,2015,10(5):e0123779.
[24]贾月慧,韩莹琰,刘杰,等.生菜对镉胁迫的生理响应及体内镉的累积分布[J].农业环境科学学报,2018,37(8):1610-1618.JIA Yue-hui,HAN Ying-yan,LIU Jie,et al.Physiological responses of vegetables to cadmium stress and cucumber accumulation and distribution[J].Journal of Agro-Environment Science,2018,37(8):1610-1618.
[25]Tu-Sekine B,Raben D M.Characterization of a cinnamoyl-CoA reductase 1(CCR1)mutant in maize:Effects on lignification,fibre development,and global gene expression[J].Journal of Experimental Botany,2011,62(11):3837-3848.
[26]刘清泉,陈亚华,沈振国,等.细胞壁在植物重金属耐性中的作用[J].植物生理学报,2014(5):605-611.LIU Qing-quan,CHEN Ya-hua,SHEN Zhen-guo,et al.The role of cell wall in plant heavy metal tolerance[J].Plant Physiology Journal,2014(5):605-611.
[2]Ali H,Khan E,Sajad M A.Phytoremediation of heavy metals:Concepts and applications[J].Chemosphere,2013,91(7):869-881.
[3]Uraguchi S,Maori S,Kuramata M,et al.Root-to-shoot Cd translocation via the xylem is the major process determining shoot and grain cadmium accumulation in rice[J].Journal of Experimental Botany,2009,60(9):2677-2690.
[4]滕振宁,方宝华,刘洋,等.镉对不同品种水稻光合作用的影响[J].中国农业气象,2016,37(5):538-544.TENG Zhen-ning,FANG Bao-hua,LIU Yang,et al.Effect of cadmium on photosynthesis of different rice varieties[J].Chinese Journal of Agrometeorology,2016,37(5):538-544.
[5]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.
[6]邓丹.根系结构对水稻吸收砷的影响[D].上海:华东师范大学,2009.DENG Dan.Effect of root structure on absorption of arsenic in rice[D].Shanghai:East China Normal University,2009.
[7]李天哲,陈爱婷,李彩,等.镉胁迫下硅对水稻幼苗生长与生理响应的影响[J].农业环境科学学报,2018,37(6):1072-1078.LI Tian-zhe,CHEN Ai-ting,LI Cai,et al.Effects of silicon on the growth and physiological responses of rice seedlings under cadmium stress[J].Journal of Agro-Environment Science,2018,37(6):1072-1078.
[8]李君,葛跃,王明新,等.镉对蓖麻耐性生理及营养元素吸收转运的影响[J].环境科学学报,2016,36(8):3081-3087.LI Jun,GE Yue,WANG Ming-xin,et al.Effects of cadmium on the physiological and nutrient elements absorption and translocation of ramie[J].Acta Scientiae Circumstantiae,2016,36(8):3081-3087.
[9]Zhao F Y,Han M M,Zhang S Y,et al.Hydrogen peroxide-mediated growth of the root system occurs via auxin signaling modification and variations in the expression of cell-cycle genes in rice seedlings exposed to cadmium stress[J].Journal of Integrative Plant Biology,2012,54(12):991-1006.
[10]张欣,王华忠,王利,等.不同品种小麦幼苗耐镉差异[J].江苏农业科学,2018,46(7):61-65.ZHANG Xin,WANG Hua-zhong,WANG Li,et al.Differences in cadmium tolerance between different wheat varieties[J].Jiangsu Agricultural Sciences,2018,46(7):61-65.
[11]Zhang X F,Zhang X H,Gao B,et al.Effect of cadmium on growth,photosynthesis,mineral nutrition and metal accumulation of an energy crop,king grass(Pennisetum americanum×P.purpureum)[J].Biomass&Bioenergy,2014,67:179-187.
[12]冯汉青,杜变变,王庆文,等.镉胁迫下活性炭对小麦幼根的保护作用[J].生态学报,2016,36(10):2962-2968.FENG Han-qing,DU Bian-bian,WANG Qing-wen,et al.Protective effect of activated carbon on young roots of wheat under cadmium stress[J].Acta Ecologica Sinica,2016,36(10):2962-2968.
[13]Malamy J.Intrinsic and environmental response pathways that regulate root system architecture[J].Plant,Cell and Environment,2005,28:67-77.
[14]王艺霖,周玫,李苹,等.根系形态可塑性决定黄栌幼苗在瘠薄土壤中的适应对策[J].北京林业大学学报,2017,39(6):60-69.WANG Yi-lin,ZHOU Mei,LI Ping,et al.Root morphological plasticity determines the adaptation strategies of Astragalus seedlings in infertile soil[J].Journal of Beijing Forestry University,2017,39(6):60-69.
[15]陈杰,许长征,曹颖倩,等.不同重金属对拟南芥根系特征的影响比较[J].应用与环境生物学报,2017,23(6):1122-1128.CHEN Jie,XU Chang-zheng,CAO Ying-qian,et al.Comparison of the effects of different heavy metals on the root characteristics of Arabidopsis thaliana[J].Chinese Journal of Applied&Environmental Biology,2017,23(6):1122-1128.
[16]Lux A,Martinka M,Vaculík M,et al.Root responses to cadmium in the rhizosphere:A review[J].Journal of Experimental Botany,2011,62(1):21-37.
[17]VaculíM,Konlechner C,Langer I,et al.Root anatomy and element distribution vary between two Salix caprea isolates with different Cd accumulation capacities[J].Environmental Pollution,2012,163(1):117-126.
[18]Lux A,SottníkováA,OpatrnáJ,et al.Differences in structure of adventitious roots in Salix clones with contrasting characteristics of cadmium accumulation and sensitivity[J].Physiol Plant,2010,120(4):537-545.
[19]Ostonen I,Püttseppü,Biel C,et al.Specific root length as an indicator of environmental change[J].Giornale Botanico Italiano,2007,141(3):426-442.
[20]Lu Z,Zhang Z,Su Y,et al.Cultivar variation in morphological response of peanut roots to cadmium stress and its relation to cadmium accumulation[J].Ecotoxicology&Environmental Safety,2013,91(4):147-155.
[21]姜涛.铝胁迫对饭豆根尖营养元素吸收的影响及可能的调控机制[D].杭州:浙江大学,2013.JIANG Tao.Effects of aluminum stress on nutrient absorption of root tips of rice bean and its possible regulation mechanism[D].Hangzhou:Zhejiang University,2013.
[22]张苏波.不同水稻品种吸收重金属特点研究[D].扬州:扬州大学,2016.ZHANG Su-bo.Characteristics of absorption of heavy metals in different rice varieties[D].Yangzhou:Yangzhou University,2016.
[23]Gao W,Nan T,Tan G,et al.Cellular and subcellular immunohistochemical localization and quantification of cadmium ions in wheat(Triticum aestivum)[J].PLoS One,2015,10(5):e0123779.
[24]贾月慧,韩莹琰,刘杰,等.生菜对镉胁迫的生理响应及体内镉的累积分布[J].农业环境科学学报,2018,37(8):1610-1618.JIA Yue-hui,HAN Ying-yan,LIU Jie,et al.Physiological responses of vegetables to cadmium stress and cucumber accumulation and distribution[J].Journal of Agro-Environment Science,2018,37(8):1610-1618.
[25]Tu-Sekine B,Raben D M.Characterization of a cinnamoyl-CoA reductase 1(CCR1)mutant in maize:Effects on lignification,fibre development,and global gene expression[J].Journal of Experimental Botany,2011,62(11):3837-3848.
[26]刘清泉,陈亚华,沈振国,等.细胞壁在植物重金属耐性中的作用[J].植物生理学报,2014(5):605-611.LIU Qing-quan,CHEN Ya-hua,SHEN Zhen-guo,et al.The role of cell wall in plant heavy metal tolerance[J].Plant Physiology Journal,2014(5):605-611.