Research Advances on Plant Root Exudates in Response to Heavy Metal Stress

LIU Changfeng; DUAN Shixin; ZHANG Xiaoyu; WANG Ye; WANG Tianchu

doi:10.19303/j.issn.1008-0384.2021.12.016

Volume 36 Issue 12

Dec. 2021

Turn off MathJax

Article Contents

Article Navigation > Fujian Journal of Agricultural Sciences > 2021 > 36(12): 1506-1514

LIU C F, DUAN S X, ZHANG X Y, et al. Research Advances on Plant Root Exudates in Response to Heavy Metal Stress [J]. Fujian Journal of Agricultural Sciences，2021，36（12）：1506−1514 doi: 10.19303/j.issn.1008-0384.2021.12.016

Citation:

LIU C F, DUAN S X, ZHANG X Y, et al. Research Advances on Plant Root Exudates in Response to Heavy Metal Stress [J]. Fujian Journal of Agricultural Sciences，2021，36（12）：1506−1514 doi: 10.19303/j.issn.1008-0384.2021.12.016

Citation:

PDF( 820 KB)

Research Advances on Plant Root Exudates in Response to Heavy Metal Stress

doi: 10.19303/j.issn.1008-0384.2021.12.016

School of Environmental and Safety Engineering, Shenyang University of Chemical Technology, Shenyang, Liaoning　110142, China

Received Date: 2021-08-04
Rev Recd Date: 2021-10-28

Available Online: 2021-12-30

Publish Date: 2021-12-28

Abstract

Abstract

In response to heavy metal stress plants alter the root exudate secretion in ways depending on the plant species and type of heavy metals, among other factors. This article reviews the published literature on the organic acids, amino acids, and soluble sugars in root exudates and their roles in the chemistry and physiology of the plants under varieties of heavy metal stresses. The referred material and documents concerning the tolerance and adaptability of plants to heavy metals as well as the response mechanisms involving the key chemicals would provide a concise and update information for the scientists interested in the field of study.
- Soil,
- heavy metal,
- stress,
- root exudates

FullText(HTML)

References(90)

References

[1]	陈能场, 郑煜基, 何晓峰, 等. 《全国土壤污染状况调查公报》探析 [J]. 农业环境科学学报, 2017, 36(9):1689−1692. doi: 10.11654/jaes.2017-1220 CHEN N C, ZHENG Y J, HE X F, et al. Analysis of the Report on the national general survey of soil contamination [J]. Journal of Agro-Environment Science, 2017, 36(9): 1689−1692.(in Chinese) doi: 10.11654/jaes.2017-1220
[2]	杨寿南. 探究我国耕地土壤重金属污染现状与防治对策 [J]. 环境与发展, 2018, 30(6):57, 60. YANG S N. Exploring the status quo of heavy metal pollution in arable land in China and its control measures [J]. Environment and Development, 2018, 30(6): 57, 60.(in Chinese)
[3]	SUN L J, CAO X Y, TAN C Y, et al. Analysis of the effect of cadmium stress on root exudates of Sedum plumbizincicola based on metabolomics [J]. Ecotoxicology and Environmental Safety, 2020, 205: 111152. doi: 10.1016/j.ecoenv.2020.111152
[4]	王学礼, 常青山, 侯晓龙, 等. 三明铅锌矿区植物对重金属的富集特征 [J]. 生态环境学报, 2010, 19(1):108−112. doi: 10.3969/j.issn.1674-5906.2010.01.021 WANG X L, CHANG Q S, HOU X L, et al. Heavy metal enrichment of plants at lead-zinc mines in South China [J]. Ecology and Environmental Sciences, 2010, 19(1): 108−112.(in Chinese) doi: 10.3969/j.issn.1674-5906.2010.01.021
[5]	FOY C D. Plant adaptation to acid, aluminum-toxic soils [J]. Communications in Soil Science and Plant Analysis, 1988, 19(7/8/9/10/11/12): 959−987.
[6]	张冉, 韩博, 任健, 等. 铝对植物毒害及草本植物耐铝毒机制研究进展 [J]. 云南农业大学学报(自然科学), 2020, 35(2):353−360. ZHANG R, HAN B, REN J, et al. Research progress on aluminum toxicity to plants and mechanisms of aluminum tolerance in herbaceous [J]. Journal of Yunnan Agricultural University (Natural Science), 2020, 35(2): 353−360.(in Chinese)
[7]	宋志政, 周润声. 我国重金属污染土壤的治理与修复研究进展 [J]. 化工设计通讯, 2020, 46(2):216−217. doi: 10.3969/j.issn.1003-6490.2020.02.144 SONG Z Z, ZHOU R S. Research progress in remediation and remediation of heavy metal contaminated soil in China [J]. Chemical Engineering Design Communications, 2020, 46(2): 216−217.(in Chinese) doi: 10.3969/j.issn.1003-6490.2020.02.144
[8]	CURL E A, TRUELOVE B. The rhizosphere[M]. Berlin, Heidelberg: Springer, 1986.
[9]	涂书新, 吴佳. 植物根系分泌物研究方法评述 [J]. 生态环境学报, 2010, 19(10):2493−2500. doi: 10.3969/j.issn.1674-5906.2010.10.041 TU S X, WU J. A review on research methods of root exudates [J]. Ecology and Environmental Sciences, 2010, 19(10): 2493−2500.(in Chinese) doi: 10.3969/j.issn.1674-5906.2010.10.041
[10]	赵宽, 周葆华, 马万征, 等. 不同环境胁迫对根系分泌有机酸的影响研究进展 [J]. 土壤, 2016, 48(2):235−240. ZHAO K, ZHOU B H, MA W Z, et al. The influence of different environmental stresses on root-exuded organic acids: A review [J]. Soils, 2016, 48(2): 235−240.(in Chinese)
[11]	FENG R W, LEI L, SU J M, et al. Toxicity of different forms of antimony to rice plant: Effects on root exudates, cell wall components, endogenous hormones and antioxidant system [J]. Science of the Total Environment, 2020, 711: 134589. doi: 10.1016/j.scitotenv.2019.134589
[12]	ROVIRA A D, FOSTER R C, MARTIN J K. Note on terminology: Origin, nature and nomenclature of the organic materials in the rhizosphere[J]. The Soil–Root Interface. 1979: 1−4.
[13]	WAREMBOURG F R, BILLES G. Estimating carbon transfers in the plant rhizosphere[J]. The Soil–Root Interface. 1979: 183-196.
[14]	施卫明. 根系分泌物与养分有效性 [J]. 土壤, 1993, 25(5):252−256. SHI W M. Root exudates and nutrient availability [J]. Soils, 1993, 25(5): 252−256.(in Chinese)
[15]	ADELEKE R, NWANGBURUKA C, OBOIRIEN B. Origins, roles and fate of organic acids in soils: A review [J]. South African Journal of Botany, 2017, 108: 393−406. doi: 10.1016/j.sajb.2016.09.002
[16]	李雪莲. 东南景天镉超积累生态型根系分泌物的研究[D]. 杭州: 浙江大学, 2011. LI X L. Studies on root exudates of the cadmium hyperaccumulating ecotype of Sedum alfredii hance[D]. Hangzhou: Zhejiang University, 2011. (in Chinese)
[17]	周翠. 外源有机酸对秋华柳镉积累效率的影响[D]. 重庆: 西南大学, 2018. ZHOU C. Effects of exogenous organic acids on cadmium accumulation efficiency of Salix variegata franch[D]. Chongqing: Southwest University, 2018. (in Chinese)
[18]	PINTO A P, SIM[OTILDE]ES I, MOTA A M. Cadmium impact on root exudates of Sorghum and maize plants: A speciation study [J]. Journal of Plant Nutrition, 2008, 31(10): 1746−1755. doi: 10.1080/01904160802324829
[19]	郭山. Cd胁迫对凤眼莲(Eichhornia crassipes)根系分泌及体内小分子有机物代谢的影响研究[D]. 武汉: 华中农业大学, 2018. GUO S. Effects of cadmium stress on metabolism of low molecule weight organic compounds in root exudates and organs of Eichhornia crassipes[D]. Wuhan: Huazhong Agricultural University, 2018. (in Chinese)
[20]	FU H J, YU H Y, LI T X, et al. Influence of cadmium stress on root exudates of high cadmium accumulating rice line (Oryza sativa L.) [J]. Ecotoxicology and Environmental Safety, 2018, 150: 168−175. doi: 10.1016/j.ecoenv.2017.12.014
[21]	侯晓龙. 铅超富集植物金丝草对Pb胁迫的响应机制研究[D]. 福州: 福建农林大学, 2013. HOU X L. Response mechnism of Pb hypcraccumulator Pogonatherum crinitum to Pb stress[D]. Fuzhou: Fujian Agriculture and Forestry University, 2013. (in Chinese)
[22]	聂磊, 官晓东, 钟秋凤. 铅胁迫对景天属和花生属植物生理特性和根系分泌物的影响 [J]. 湖北农业科学, 2014, 53(16):3760−3764, 3769. doi: 10.3969/j.issn.0439-8114.2014.16.010 NIE L, GUAN X D, ZHONG Q F. Effects of lead stress on root exudates and physiological characteristics of Sedum and Arachis plants [J]. Hubei Agricultural Sciences, 2014, 53(16): 3760−3764, 3769.(in Chinese) doi: 10.3969/j.issn.0439-8114.2014.16.010
[23]	林海涛, 史衍玺. 铅、镉胁迫对茶树根系分泌有机酸的影响 [J]. 山东农业科学, 2005, 37(2):32−34. doi: 10.3969/j.issn.1001-4942.2005.02.011 LIN H T, SHI Y X. Effects of lead and cadmium stress on the secretion of organic acids by tea roots [J]. Shandong Agricultural Sciences, 2005, 37(2): 32−34.(in Chinese) doi: 10.3969/j.issn.1001-4942.2005.02.011
[24]	ZU Y Q, LI Y, MIN H, et al. Subcellular distribution and chemical form of Pb in hyperaccumulator Arenaria orbiculata and response of root exudates to Pb addition [J]. Frontiers of Environmental Science & Engineering, 2015, 9(2): 250−258.
[25]	杨菊云. 根系分泌物对苔草铁膜形成及铅胁迫下对根际环境的影响[D]. 南昌: 南昌大学, 2014. YANG J Y. Impact of root exudates of Carex cinerascens on iron plaque formation and the rhizosphere under lead stress[D]. Nanchang: Nanchang University, 2014. (in Chinese)
[26]	LYUBENOVA L, KUHN A J, HÖLTKEMEIER A, et al. Root exudation pattern of Typha latifolia L. plants after copper exposure [J]. Plant and Soil, 2013, 370(1/2): 187−195.
[27]	HUANG G Y, ZHOU X P, GUO G, et al. Variations of dissolved organic matter and Cu fractions in rhizosphere soil induced by the root activities of Castor bean [J]. Chemosphere, 2020, 254: 126800. doi: 10.1016/j.chemosphere.2020.126800
[28]	柴民伟. 外来种互花米草和黄顶菊对重金属和盐碱胁迫的生态响应[D]. 天津: 南开大学, 2013. CHAI M W. Ecological responses of exotic species Spartina alterniflora and Flaveria bidentis to heavy metal and saline-alkali stresses[D]. Tianjin: Nankai University, 2013. (in Chinese)
[29]	MLECZEK M, GĄSECKA M, WALISZEWSKA B, et al. Salix viminalis L.-A highly effective plant in phytoextraction of elements [J]. Chemosphere, 2018, 212: 67−78. doi: 10.1016/j.chemosphere.2018.08.055
[30]	文石林. 红壤丘陵区耐酸牧草筛选与铝毒控制技术研究[D]. 长沙: 湖南农业大学, 2012. WEN S L. Studies on aciduric forages selection and the techniques of eliminating aluminium toxicity in hilly red soils region[D]. Changsha: Hunan Agricultural University, 2012. (in Chinese)
[31]	刘尼歌, 莫丙波, 严小龙, 等. 大豆和水稻对铝胁迫响应的生理机制 [J]. 应用生态学报, 2007, 18(4):853−858. doi: 10.3321/j.issn:1001-9332.2007.04.025 LIU N G, MO B B, YAN X L, et al. Physiological mechanisms of soybean and rice in responses to aluminum stress [J]. Chinese Journal of Applied Ecology, 2007, 18(4): 853−858.(in Chinese) doi: 10.3321/j.issn:1001-9332.2007.04.025
[32]	钱莲文, 李清彪, 孙境蔚, 等. 铝胁迫下常绿杨根系有机酸和氨基酸的分泌 [J]. 厦门大学学报(自然科学版), 2018, 57(2):221−227. QIAN L W, LI Q B, SUN J W, et al. Root secretion of organic acids and amino acids of evergreen poplar under aluminum stress [J]. Journal of Xiamen University (Natural Science Edition), 2018, 57(2): 221−227.(in Chinese)
[33]	刘腾腾, 郜红建, 宛晓春, 等. 铝对茶树根细胞膜透性和根系分泌有机酸的影响 [J]. 茶叶科学, 2011, 31(5):458−462. doi: 10.3969/j.issn.1000-369X.2011.05.013 LIU T T, GAO H J, WAN X C, et al. Impacts of aluminum on root cell membrane permeability and organic acids in root exudates of tea plant [J]. Journal of Tea Science, 2011, 31(5): 458−462.(in Chinese) doi: 10.3969/j.issn.1000-369X.2011.05.013
[34]	王玉云. Cd胁迫对不同水稻根系分泌有机酸和氨基酸及根系Cd含量的影响[D]. 雅安: 四川农业大学, 2011. WANG Y Y. The influence of Cd stress on roots exudation organic acid and amino acid and Cd content of the different rice[D]. Yaan: Sichuan Agricultural University, 2011. (in Chinese)
[35]	吕佳莉. 镉与污水复合胁迫对玉米幼苗代谢物的GC-MS研究[D]. 太原: 山西大学, 2016. LYU J L. Effects of Cd and sewage combined pollution on corn seedling metabolite based on the GC-MS technology[D]. Taiyuan: Shanxi University, 2016. (in Chinese)
[36]	PAVLÍKOVÁ D, ZEMANOVÁ V, PROCHÁZKOVÁ D, et al. The long-term effect of zinc soil contamination on selected free amino acids playing an important role in plant adaptation to stress and senescence [J]. Ecotoxicology and Environmental Safety, 2014, 100: 166−170. doi: 10.1016/j.ecoenv.2013.10.028
[37]	徐卫红, 王宏信, 刘怀, 等. Zn、Cd单一及复合污染对黑麦草根分泌物及根际Zn、Cd形态的影响 [J]. 环境科学, 2007, 28(9):2089−2095. doi: 10.3321/j.issn:0250-3301.2007.09.035 XU W H, WANG H X, LIU H, et al. Effects of individual and combined pollution of Cd and Zn on root exudates and rhizosphere Zn and Cd fractions in ryegrass(loliurn perenne L. ) [J]. Environmental Science, 2007, 28(9): 2089−2095.(in Chinese) doi: 10.3321/j.issn:0250-3301.2007.09.035
[38]	ZHAN J, HUANG H G, YU H Y, et al. Characterization of dissolved organic matter in the rhizosphere of phytostabilizer Athyrium wardii (Hook. ) involved in enhanced metal accumulation when exposed to Cd and Pb co-contamination [J]. Environmental Pollution, 2020, 266: 115196. doi: 10.1016/j.envpol.2020.115196
[39]	ZHU G X, XIAO H Y, GUO Q J, et al. Effects of cadmium stress on growth and amino acid metabolism in two Compositae plants [J]. Ecotoxicology and Environmental Safety, 2018, 158: 300−308. doi: 10.1016/j.ecoenv.2018.04.045
[40]	CHEN Y X, YU M G, DUAN D C. Tolerance, Accumulation, and Detoxification Mechanism of Copper in Elsholtzia splendens[M]. Detoxification of Heavy Metals, 2011: 317-344. DOI: 10.1007/978-3-642-21408-0_17.
[41]	JI J, SHI Z, XIE T T, et al. Responses of GABA shunt coupled with carbon and nitrogen metabolism in poplar under NaCl and CdCl₂ stresses [J]. Ecotoxicology and Environmental Safety, 2020, 193: 110322. doi: 10.1016/j.ecoenv.2020.110322
[42]	ZHOU J H, CHENG K, HUANG G M, et al. Effects of exogenous 3-indoleacetic acid and cadmium stress on the physiological and biochemical characteristics of Cinnamomum camphora [J]. Ecotoxicology and Environmental Safety, 2020, 191: 109998. doi: 10.1016/j.ecoenv.2019.109998
[43]	赵丽娟. 代谢组学技术研究氯磺隆和镉对玉米幼苗和菠菜代谢的影响[D]. 太原: 山西大学, 2016. ZHAO L J. Changes in metabolites of maize seedlings and Spinacia oleracea L. under chlorsulfuron and cadmium stress, measured by metabonomics technology[D]. Taiyuan: Shanxi University, 2016. (in Chinese)
[44]	罗庆. 镉、铅胁迫下东南景天根系分泌物的代谢组学研究[D]. 沈阳: 东北大学, 2016. LUO Q. Metabolomics study on root exudates of Sedum alfredii under Cd and Pb stress[D]. Shenyang: Northeastern University, 2016. (in Chinese)
[45]	JAVED M T, AKRAM M S, TANWIR K, et al. Cadmium spiked soil modulates root organic acids exudation and ionic contents of two differentially Cd tolerant maize (Zea mays L.) cultivars [J]. Ecotoxicology and Environmental Safety, 2017, 141: 216−225. doi: 10.1016/j.ecoenv.2017.03.027
[46]	CHEN Y T, WANG Y, YEH K C. Role of root exudates in metal acquisition and tolerance [J]. Current Opinion in Plant Biology, 2017, 39: 66−72. doi: 10.1016/j.pbi.2017.06.004
[47]	DONG J L, HUNT J, DELHAIZE E, et al. Impacts of elevated CO₂ on plant resistance to nutrient deficiency and toxic ions via root exudates: A review [J]. Science of the Total Environment, 2021, 754: 142434. doi: 10.1016/j.scitotenv.2020.142434
[48]	傅晓萍, 豆长明, 胡少平, 等. 有机酸在植物对重金属耐性和解毒机制中的作用 [J]. 植物生态学报, 2010, 34(11):1354−1358. doi: 10.3773/j.issn.1005-264x.2010.11.013 FU X P, DOU C M, HU S P, et al. A review of progress in roles of organic acids on heavy metal resistance and detoxification in plants [J]. Chinese Journal of Plant Ecology, 2010, 34(11): 1354−1358.(in Chinese) doi: 10.3773/j.issn.1005-264x.2010.11.013
[49]	MONTIEL-ROZAS M M, MADEJÓN E, MADEJÓN P. Effect of heavy metals and organic matter on root exudates (low molecular weight organic acids) of herbaceous species: An assessment in sand and soil conditions under different levels of contamination [J]. Environmental Pollution, 2016, 216: 273−281. doi: 10.1016/j.envpol.2016.05.080
[50]	LI X C, REICH T, KERSTEN M, et al. Low-molecular-weight organic acid complexation affects antimony(III) adsorption by granular ferric hydroxide [J]. Environmental Science & Technology, 2019, 53(9): 5221−5229.
[51]	DOU X K, DAI H P, SKUZA L, et al. Strong accumulation capacity of hyperaccumulator Solanum nigrum L. for low or insoluble Cd compounds in soil and its implication for phytoremediation [J]. Chemosphere, 2020, 260: 127564. doi: 10.1016/j.chemosphere.2020.127564
[52]	李廷强. 超积累植物东南景天（Sedum alfredii Hance）对锌的活化、吸收及转运机制研究[D]. 杭州: 浙江大学, 2005. LI T Q. Mechanisms of zinc activation, absorption and transport by hyperaccumulator of Sedum alfredii hance[D]. Hangzhou: Zhejiang University, 2005. (in Chinese)
[53]	TONG B. Low molecular weight organic acids in root exudates and cadmium accumulation in cadmium hyperaccumulator Solanum nigrum L. and non-hyperaccumulator Solanum lycopersicum L [J]. African Journal of Biotechnology, 2011, 10(75): 17180−17185. doi: 10.5897/ajb11.1617
[54]	YIN X B, ZHANG L J, HARIGAI M, et al. Hydrothermal-treatment desorption of cesium from clay minerals: The roles of organic acids and implications for soil decontamination [J]. Water Research, 2020, 177: 115804. doi: 10.1016/j.watres.2020.115804
[55]	SIDHU G P S, BALI A S, BHARDWAJ R. Role of organic acids in mitigating cadmium toxicity in plants[M].Cadmium Tolerance in Plants. 2019: 255-279.
[56]	GUO D, ALI A, REN C Y, et al. EDTA and organic acids assisted phytoextraction of Cd and Zn from a smelter contaminated soil by potherb mustard (Brassica juncea, Coss) and evaluation of its bioindicators [J]. Ecotoxicology and Environmental Safety, 2019, 167: 396−403. doi: 10.1016/j.ecoenv.2018.10.038
[57]	ANNING A K, AKOTO R. Assisted phytoremediation of heavy metal contaminated soil from a mined site with Typha latifolia and Chrysopogon zizanioides [J]. Ecotoxicology and Environmental Safety, 2018, 148: 97−104. doi: 10.1016/j.ecoenv.2017.10.014
[58]	GUO X F, ZHAO G H, ZHANG G X, et al. Effect of mixed chelators of EDTA, GLDA, and citric acid on bioavailability of residual heavy metals in soils and soil properties [J]. Chemosphere, 2018, 209: 776−782. doi: 10.1016/j.chemosphere.2018.06.144
[59]	TANANONCHAI A, SAMPANPANISH P, CHANPIWAT P, et al. Effect of EDTA and NTA on cadmium distribution and translocation in Pennisetum purpureum Schum cv. Mott [J]. Environmental Science and Pollution Research, 2019, 26(10): 9851−9860. doi: 10.1007/s11356-018-04103-z
[60]	DIARRA I, KOTRA K K, PRASAD S. Assessment of biodegradable chelating agents in the phytoextraction of heavy metals from multi-metal contaminated soil [J]. Chemosphere, 2021, 273: 128483. doi: 10.1016/j.chemosphere.2020.128483
[61]	HAWRYLAK-NOWAK B, DRESLER S, MATRASZEK R. Exogenous malic and acetic acids reduce cadmium phytotoxicity and enhance cadmium accumulation in roots of sunflower plants [J]. Plant Physiology and Biochemistry, 2015, 94: 225−234. doi: 10.1016/j.plaphy.2015.06.012
[62]	HUANG G Y, YOU J W, ZHOU X P, et al. Effects of low molecular weight organic acids on Cu accumulation by Castor bean and soil enzyme activities [J]. Ecotoxicology and Environmental Safety, 2020, 203: 110983. doi: 10.1016/j.ecoenv.2020.110983
[63]	KHALID H, ZIA-UR-REHMAN M, NAEEM A, et al. Solanum nigrum L.: A novel hyperaccumulator for the Phyto-management of cadmium contaminated soils[M]. Cadmium Toxicity and Tolerance in Plants. 2019: 451−477.
[64]	SUN R L, ZHOU Q X, JIN C X. Cadmium accumulation in relation to organic acids in leaves of Solanum nigrum L. as a newly found cadmium hyperaccumulator [J]. Plant and Soil, 2006, 285(1/2): 125−134.
[65]	XIN J L, HUANG B F, DAI H W, et al. Characterization of cadmium uptake, translocation, and distribution in young seedlings of two hot pepper cultivars that differ in fruit cadmium concentration [J]. Environmental Science and Pollution Research, 2014, 21(12): 7449−7456. doi: 10.1007/s11356-014-2691-4
[66]	HE B Y, YU D P, CHEN Y, et al. Use of low-calcium cultivars to reduce cadmium uptake and accumulation in edible amaranth (Amaranthus mangostanus L.) [J]. Chemosphere, 2017, 171: 588−594. doi: 10.1016/j.chemosphere.2016.12.085
[67]	WU J W, GEILFUS C M, PITANN B, et al. Silicon-enhanced oxalate exudation contributes to alleviation of cadmium toxicity in wheat [J]. Environmental and Experimental Botany, 2016, 131: 10−18. doi: 10.1016/j.envexpbot.2016.06.012
[68]	KIM S H, LEE I S. Comparison of the ability of organic acids and EDTA to enhance the phytoextraction of metals from a multi-metal contaminated soil [J]. Bulletin of Environmental Contamination and Toxicology, 2010, 84(2): 255−259. doi: 10.1007/s00128-009-9888-0
[69]	YANG J L, ZHENG S J, HE Y F, et al. Aluminium resistance requires resistance to acid stress: A case study with spinach that exudes oxalate rapidly when exposed to Al stress [J]. Journal of Experimental Botany, 2005, 56(414): 1197−1203. doi: 10.1093/jxb/eri113
[70]	WURST S, WAGENAAR R, BIERE A, et al. Microorganisms and Nematodes increase levels of secondary metabolites in roots and root exudates of Plantago lanceolata [J]. Plant and Soil, 2010, 329(1/2): 117−126.
[71]	田聪, 张烁, 粟畅, 等. 铝胁迫下大豆根系有机酸积累的特性 [J]. 大豆科学, 2017, 36(2):256−261. TIAN C, ZHANG S, SU C, et al. Effects of aluminum (Al) on organic acid accumulation in soybean roots [J]. Soybean Science, 2017, 36(2): 256−261.(in Chinese)
[72]	WANG Q, ZHANG W J, HE L Y, et al. Increased biomass and quality and reduced heavy metal accumulation of edible tissues of vegetables in the presence of Cd-tolerant and immobilizing Bacillus megaterium H3 [J]. Ecotoxicology and Environmental Safety, 2018, 148: 269−274. doi: 10.1016/j.ecoenv.2017.10.036
[73]	XU J, SUN J H, DU L G, et al. Comparative transcriptome analysis of cadmium responses in Solanum nigrum and Solanum torvum [J]. The New Phytologist, 2012, 196(1): 110−124. doi: 10.1111/j.1469-8137.2012.04235.x
[74]	XU J, ZHU Y Y, GE Q, et al. Comparative physiological responses of Solanum nigrum and Solanum torvum to cadmium stress [J]. The New Phytologist, 2012, 196(1): 125−138. doi: 10.1111/j.1469-8137.2012.04236.x
[75]	JIN Y Q, ZHU H F, LUO S, et al. Role of maize root exudates in promotion of colonization of Bacillus velezensis strain S3-1 in rhizosphere soil and root tissue [J]. Current Microbiology, 2019, 76(7): 855−862. doi: 10.1007/s00284-019-01699-4
[76]	XIE X Y, WEISS D J, WENG B S, et al. The short-term effect of cadmium on low molecular weight organic acid and amino acid exudation from mangrove (Kandelia obovata (S., L. ) Yong) roots [J]. Environmental Science and Pollution Research, 2013, 20(2): 997−1008. doi: 10.1007/s11356-012-1031-9
[77]	ZEMANOVÁ V, PAVLÍK M, PAVLÍKOVÁ D. Cadmium toxicity induced contrasting patterns of concentrations of free sarcosine, specific amino acids and selected microelements in two Noccaea species [J]. PLoS One, 2017, 12(5): e0177963. doi: 10.1371/journal.pone.0177963
[78]	王佳钰, 李萌, 宋晓卉, 等. 代谢组学在植物重金属胁迫研究中的应用 [J]. 生物化工, 2020, 6(2):128−132. doi: 10.3969/j.issn.2096-0387.2020.02.037 WANG J Y, LI M, SONG X H, et al. The application of metabonomics in study of plant under heavy metal stress [J]. Biological Chemical Engineering, 2020, 6(2): 128−132.(in Chinese) doi: 10.3969/j.issn.2096-0387.2020.02.037
[79]	徐超. 脯氨酸与重金属耐性和富集的研究进展 [J]. 中国资源综合利用, 2018, 36(2):80−83. doi: 10.3969/j.issn.1008-9500.2018.02.030 XU C. A review of amino acid in heavy metal tolerance and accumulation [J]. China Resources Comprehensive Utilization, 2018, 36(2): 80−83.(in Chinese) doi: 10.3969/j.issn.1008-9500.2018.02.030
[80]	PAVLÍKOVÁ D, PAVLÍK M, STASZKOVÁ L, et al. Glutamate kinase as a potential biomarker of heavy metal stress in plants [J]. Ecotoxicology and Environmental Safety, 2008, 70(2): 223−230. doi: 10.1016/j.ecoenv.2007.07.006
[81]	JOSHI V, JOUNG J G, FEI Z J, et al. Interdependence of threonine, methionine and isoleucine metabolism in plants: Accumulation and transcriptional regulation under abiotic stress [J]. Amino Acids, 2010, 39(4): 933−947. doi: 10.1007/s00726-010-0505-7
[82]	XIE M D, CHEN W Q, LAI X C, et al. Metabolic responses and their correlations with phytochelatins in Amaranthus hypochondriacus under cadmium stress [J]. Environmental Pollution, 2019, 252: 1791−1800. doi: 10.1016/j.envpol.2019.06.103
[83]	SHARMA S S, DIETZ K J. The significance of amino acids and amino acid-derived molecules in plant responses and adaptation to heavy metal stress [J]. Journal of Experimental Botany, 2006, 57(4): 711−726. doi: 10.1093/jxb/erj073
[84]	HAHM M S, SON J S, HWANG Y J, et al. Alleviation of salt stress in pepper (Capsicum annum L. ) plants by plant growth-promoting rhizobacteria [J]. Journal of Microbiology and Biotechnology, 2017, 27(10): 1790−1797. doi: 10.4014/jmb.1609.09042
[85]	PRAMANIK K, MITRA S, SARKAR A, et al. Characterization of cadmium-resistant Klebsiella pneumoniae MCC 3091 promoted rice seedling growth by alleviating phytotoxicity of cadmium [J]. Environmental Science and Pollution Research, 2017, 24(31): 24419−24437. doi: 10.1007/s11356-017-0033-z
[86]	王若男, 乜兰春, 张双双, 等. 植物抗重金属胁迫研究进展 [J]. 园艺学报, 2019, 46(1):157−170. WANG R N, NIE L C, ZHANG S S, et al. Research progress on plant resistance to heavy metal stress [J]. Acta Horticulturae Sinica, 2019, 46(1): 157−170.(in Chinese)
[87]	KRASENSKY J, JONAK C. Drought, salt, and temperature stress-induced metabolic rearrangements and regulatory networks [J]. Journal of Experimental Botany, 2012, 63(4): 1593−1608. doi: 10.1093/jxb/err460
[88]	DEBNATH M, ASHWATH N, HILL C B, et al. Comparative metabolic and ionomic profiling of two cultivars of Stevia rebaudiana Bert. (Bertoni) grown under salinity stress [J]. Plant Physiology and Biochemistry, 2018, 129: 56−70. doi: 10.1016/j.plaphy.2018.05.001
[89]	MAO Q Z, TANG L Z, JI W W, et al. Elevated CO₂ and soil mercury stress affect photosynthetic characteristics and mercury accumulation of rice [J]. Ecotoxicology and Environmental Safety, 2021, 208: 111605. doi: 10.1016/j.ecoenv.2020.111605
[90]	ABDELKRIM S, JEBARA S H, JEBARA M. Antioxidant systems responses and the compatible solutes as contributing factors to lead accumulation and tolerance in Lathyrus sativus inoculated by plant growth promoting rhizobacteria [J]. Ecotoxicology and Environmental Safety, 2018, 166: 427−436. doi: 10.1016/j.ecoenv.2018.09.115