外源脯氨酸降低Cd对喜旱莲子草的迫害  

Reduction in heavy metal Cd accumulation by exogenous proline in Alternanthera philoxeroides

作　　者：王希武 桂晴 胡伟[1,3] 杨玉洁[1,2] WANG Xiwu;GUI Qing;HU Wei;YANG Yujie(Engineering Research Center of Wetland Ecology and Agricultural Utilization,Ministry of Education,Yangtze University,Jingzhou 434025,Hubei,China;College of Horticulture and Gardening,Yangtze University,Jingzhou 434025,Hubei,China;College of Animal Science,Yangtze University,Jingzhou 434025,Hubei,China)

机构地区：[1]长江大学湿地生态与农业利用教育部工程研究中心,湖北荆州434025 [2]长江大学园艺园林学院,湖北荆州434025 [3]长江大学动物科学学院,湖北荆州434025

出　　处：《草业科学》2024年第6期1359-1370,共12页Pratacultural Science

基　　金：长江大学湿地生态与农业利用教育部工程研究中心开放基金项目(KF202313);江苏省科学技术厅现代农业重点项目(2022Z21007)。

摘　　要：喜旱莲子草(Alternanthera philoxeroides)为苋科多年生草本植物,是重金属镉(Cd)的超富集植物,具有药用价值高、抗逆性强等特点,是一种Cd污染土壤修复的重要候选植物。为探究添加外源脯氨酸条件下,重金属Cd对喜旱莲子草的形态、生理指标、抗氧化系统等的影响,以同一水域的喜旱莲子草为试验材料进行一系列生理生化试验,旨在揭示Cd毒害下,外施脯氨酸对喜旱莲子草的作用机理。结果表明,从形态指标上看,喜旱莲子草受到Cd毒害时,其根、茎、叶的生长明显受到抑制。但在外施脯氨酸的条件下,能够缓解Cd对喜旱莲子草所造成的伤害,降低Cd对喜旱莲子草的毒害作用。从生理指标上看,喜旱莲子草在Cd的毒害作用下,其丙二醛(MDA)、过氧化氢(H_(2)O_(2))、游离脯氨酸(Pro)、可溶性糖(SS)显著提高,可溶性蛋白(SP)处理之间差异并不显著。从抗氧化系统指标上看,喜旱莲子草在Cd的毒害作用下,其谷胱甘肽过氧化物酶(GPX)、过氧化物酶(POD)、过氧化氢酶(CAT)、超氧化物歧化酶(SOD)含量显著提高,但在茎部处理之间SOD含量差异不显著。总体来看,对喜旱莲子草添加外源脯氨酸,能够缓解Cd对喜旱莲子草的毒害作用。以此,为今后喜旱莲子草在修复Cd污染土壤方面的开发利用提供科学理论基础和参考依据。A perennial herb from the Amaranthaceae family,Alternanthera philoxeroides is a hyperaccumulator of the heavy metal cadmium(Cd).It possesses high medicinal value and demonstrates exceptional resistance.As such,it stands as a promising candidate for the remediation of cadmium-contaminated soil.To investigate the effects of heavy metal cadmium(Cd)on the morphology,physiological index,and antioxidant system of A.philoxeroides,we conducted a series of physiological and biochemical experiments using this plant species within the same watershed with proline added exogenously.This study aimed to unravel the mechanisms by which externally applied proline influences A.philoxeroides under Cd toxicity.The results revealed that Cd inhibits A.philoxeroides roots,stems,and leaves.However,when external proline was applied,it mitigated the damage caused by Cd,alleviating the toxic effects of Cd on A.philoxeroides.Concerning physiological indices,the levels of malondialdehyde(MDA),hydrogen peroxide(H_(2)O_(2)),free proline(Pro),and soluble sugar(SS)of A.philoxeroides were significantly increased under Cd-induced toxicity.Meanwhile,there were no significant differences in soluble protein(SP)levels among treatments.Regarding antioxidant system indices,Cd toxicity significantly increased the contents of Glutathione peroxidase(GPX),peroxidase(POD),catalase(CAT),and superoxide dismutase(SOD)contents were significantly increased by in A.philoxeroides.but the differences were not significant between treatments for SOD contents in the stem.In summary,the addition of exogenous proline to A.philoxeroides proved effective in mitigating the toxic effects of Cd.In order to provide a scientific theoretical basis and reference basis for the future development and utilization of A.philoxeroides in the remediation of Cd-contaminated soil.

关 键 词：喜旱莲子草 重金属 镉 脯氨酸 形态指标 生理指标 抗氧化酶活性 

分 类 号：X173[环境科学与工程—环境科学] Q945.78[生物学—植物学]