改良剂对锰超富集植物短毛蓼锰吸收及抗氧化酶系统的影响

为了探究改良剂与超富集植物联合修复锰(Mn)污染土壤,采用温室土培的方法,研究了Mn污染土壤分别添加25、50 g/kg的海泡石(S2.5,S5)和沸石(Z2.5,Z5)对Mn超富集植物短毛蓼(Polygonum pubescens Blume)生长、Mn吸收及叶片抗氧化酶系统的影响。结果表明:改良剂添加显著增加了短毛蓼茎、叶中Mn的含量(P0.05),但降低了株重、叶绿素a和叶绿素b含量。S2.5、Z5.0处理的株高比对照提高了15%和16%,Z2.5与Z5.0处理分别比对照降低了40.05%、35.58%。沸石和海泡石添加显著提高了短毛蓼叶片中MDA含量及H2O2含量(P0.05),表明短毛蓼受到了一定胁迫。超氧自由基(·O2–)含量在S2.5、S5.0、Z2.5处理时下降了4.69%、16.49%、21.01%。同时沸石和海泡石引起了短毛蓼抗氧化酶活性和非酶物质含量的改变。海泡石显著提高(P0.05)短毛蓼叶片中超氧歧化酶(SOD)活性,在S2.5、S5.0处理下,SOD活性分别比对照提高了14%和15%;POD、CAT活性也均有不同程度提高,在S2.5、S5.0处理下,POD分别是对照的4.63、4.23倍,Z2.5、Z5.0处理分别是对照的4.71、4.74倍;但显著降低了抗坏血酸过氧化物酶活性以及–SH、GSH含量(P0.05)。表明沸石和海泡石对短毛蓼抗氧化酶系统的影响不一。

Effects of Mineral Amendment on Manganese Absorption and Antioxidant Enzymes Activities in Hyperaccumulator Polygonum pubescens Blume

The main objective of the present study was to investigate the amendments to remediate manganese pollution soil combined hyperaccumulator plants. By using soil incubation experiment, 2.5% and 5% of sepiolite (S2.5, S5.0) and zeolite (Z2.5, Z5.0) were added to study the effects on Mn hyperaccumulator Polygonum pubescens Blume's growth, Mn absorption and antioxidant enzyme activities. The results showed that sepiolite and zeolite significantly increased Mn in the leaves of P. pubescens (P<0.05). However, sepiolite and zeolite also decreased the plant weight, the contents of chlorophyll a and b in the leaves of P. pubescens. S2.5 and Z5.0 treatments increased the height of P. pubescens by 15% and 16%, respectively, compared to the control group, while Z2.5 and Z5.0 decreased the height of P. pubescens by 40.05% and 35.58% respectively. In addition, sepiolite and zeolite significantly increased the contents of MDA and H2O2 (P<0.05) indicating the P. pubescens was under surpress. The content of superoxide radical (·O2–) decreased 4.69%, 16.49% and 21.01% in S2.5, S5.0 and Z2.5 treatments, respectively. Furthermore, sepiolite and zeolite changed the activities of the antioxidant enzymes and the content of non-enzymes antioxidant. Sepiolite significantly increased the activity of superoxide dismutase (SOD) in the leaves, as indicated by the results that S2.5 and S5.0 treatments increased SOD activity by 14% and 15% respectively. The activities of peroxidase (POD) and catalase (CAT) also increased. The activities of POD were 4.63 and 4.23 times of the control in the S2.5 and S5.0 groups respectively. Z2.5 and Z5.0 treatments increased POD activities by 4.71 times and 4.74 times of the controls. However, both sepiolite and zeolite decreased the activity of ascorbate peroxidase (APX), –SH and GSH (P<0.05). These results demonstrate that sepiolite and zeolite have different impacts on the antioxidant enzymes inP. pubescens.