| 水培条件下聚合草对Pb、Zn和Cd重金属的响应特征 |
| 摘要点击 128 全文点击 11 投稿时间：2024-01-26 修订日期：2024-08-16 |
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| 中文关键词 重金属 聚合草 水培条件 响应特征 抗氧化酶活性 富集机制 |
| 英文关键词 heavy metal Symphytum officinale L. hydroponic condition responsive characteristic antioxidant enzyme activities enrichment mechanism |
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| 中文摘要 |
| 在土壤重金属污染日益严峻的背景下，深入探究植物对重金属的响应机制与修复潜力，对生态环境修复意义重大. 以聚合草为对象，采用水培盆栽试验，设置不同浓度梯度的Pb、Zn、Cd单一及复合胁迫环境，通过观测生长指标、抗氧化酶（SOD、CAT、POD）活性、丙二醛（MDA）与脯氨酸（Pro）含量，以及对Pb、Zn、Cd的富集量，全面剖析聚合草对重金属的胁迫响应与富集特性. 研究表明，重金属胁迫对聚合草生长影响显著，其生物量、叶长、叶宽及茎秆长度与胁迫浓度呈负相关，且复合胁迫的抑制效应更为突出. 然而，聚合草对单一及复合胁迫均表现出良好的耐受性，仅根系受抑制程度因重金属种类与浓度而异. 在生理生化层面，重金属胁迫抑制了叶绿素的合成，并对SOD、POD、CAT等抗氧化酶活性以及MDA、Pro含量产生复杂影响. 复合胁迫相较于单一胁迫，对酶活性的抑制作用通常更为强烈，且不同重金属胁迫下，各指标呈现出不同的变化趋势. 富集能力方面，聚合草对Pb、Zn、Cd的吸收富集量随胁迫浓度升高而显著增加，根系的富集量明显高于地上部分，且单一胁迫下的富集能力强于复合胁迫. 尽管其对重金属的转移效果欠佳，但其富集能力远超普通植物，具备一定的耐性与解毒能力，是修复重金属污染土壤的优质种质资源. 研究可为聚合草在污染土壤修复中的应用及相关机制研究提供关键支撑. |
| 英文摘要 |
| In the context of the increasingly serious soil heavy metal pollution， delving deeply into the response mechanisms of plants to heavy metals and their remediation potential is of great significance for the restoration of the ecological environment. This study investigated Symphytum officinale L. via hydroponic pot experiments under single and combined stresses of lead （Pb）， zinc （Zn）， and cadmium （Cd） with different concentration gradients. Through a systematic analysis of growth indicators， antioxidant enzyme activities （superoxide dismutase [SOD]， catalase [CAT]， peroxidase [POD]）， malondialdehyde （MDA） and proline （Pro） contents， as well as heavy metal accumulation patterns， we comprehensively clarified the stress response and accumulation characteristics of comfrey under heavy metal exposure. The results demonstrated that heavy metal stress exerts a significant influence on the growth of Symphytum officinale L.. Its biomass， leaf length， leaf width， and stem length are negatively correlated with the stress concentration， and the inhibitory effect of combined stress is more pronounced. Nevertheless， Symphytum officinale L. shows good tolerance to both single and combined stresses. Only the degree of root inhibition varies according to the type and concentration of heavy metals. At the physiological and biochemical levels， heavy metal stress inhibits the synthesis of chlorophyll and has complex effects on the activities of antioxidant enzymes such as SOD， POD， and CAT， as well as the contents of MDA and Pro. Compared with single stress， combined stress generally has a more intense inhibitory effect on enzyme activities. Under different heavy-metal stresses， each indicator presents different changing trends. Regarding accumulation capacity， the absorption and enrichment amounts of Pb， Zn， and Cd by Symphytum officinale L. increase significantly with the increase of stress concentration. The enrichment amount in roots is significantly higher than that in the aboveground counterparts， and the enrichment ability under single stress is stronger than that under combined stress. Although its transfer effect on heavy metals is not ideal， its enrichment ability far exceeds that of common plants. It has certain tolerance and detoxification abilities and is an excellent germplasm resource for remediating heavy - metal - polluted soil. This study provides crucial support for the application of Symphytum officinale L. in the remediation of polluted soil and the research on related mechanisms. |
