锑胁迫下腐殖质对头花蓼体内锑形态及生化特性影响

锑(Sb)是一种无延展性的有色金属,具有潜在毒性和致癌性,对心血管、呼吸系统和肝脏等都会造成危害。并且,随着近几年锑资源的持续开发,土壤中的Sb污染被广泛关注。腐殖质具有复杂结构并包含有羧基、醇羟基等多种活性官能团,对重金属在土壤中的形态转化、迁移能力以及生物可利用性具有重要影响。头花蓼作为民间常用草药并且也是贵州省特色苗药,在土壤Sb背景值极高的独山锑矿区不仅能大量生长,并且在其体内Sb含量远高于其他未受污染的陆生植物时,仍然可以表现出良好的生长状态。为了探究腐殖质对独山矿区内Sb污染土壤中头花蓼植物有效性的影响。选取贵州省独山县东峰Sb区附近Sb污染土壤与头花蓼种子作为试验样品,通过三种不同腐殖质富里酸、胡敏素、胡敏酸对Sb污染土壤进行30d的培育实验后种植头花蓼。结果表明：(1)腐殖质添加后使得头花蓼叶绿素总量整体呈现上升的趋势,加强了头花蓼光合作用。(2)头花蓼的逆境生理现象表现为：在低添加量下,胡敏素实验组与胡敏酸实验组中丙二醛含量下降,SOD酶活性升高,CAT酶活性下降；说明胡敏素和的胡敏酸在低添加量下能够有效缓解头花蓼所受到的Sb毒害；而高添加量富里酸对头花蓼有一定损害。(3)低添加量的胡敏酸能够有效缓解头花蓼植株所受到的重金属Sb、As、Cd、Cu胁迫。(4)相比于胡敏素和胡敏酸,富里酸更容易促进头花蓼体内残渣态Sb向更活跃的赋存形态转化；胡敏酸对头花蓼中的Sb赋存形态表现出了低浓度活化而高浓度钝化的现象；胡敏素则能够有效降低头花蓼体内Sb活性。

Effects of Humus on Morphology and Biochemical Characteristics of Antimony in Polygonum capitatum under Antimony Stress

Antimony (Sb) is a non-malleable nonferrous metal with potential toxicity and carcinogenicity, which can be huminic acidrmful to cardiovascular, respiratory system and liver. Humus huminic acids a complex structure and contains a variety of reactive functional groups such as carboxyl groups and alcohol hydroxyl groups, which huminic acidve important effects on the morphological transformation, migration ability and bioavailability of heavy metals in soil. Polygonum cuspidatum, as a common folk medicine and also a chuminic acidracteristic Miao medicine in Guizhou province, not only grows abundantly in the Dushuminic acidn antimony mining area where the soil Sb background value is extremely high, but also shows good growth when its Sb content is much higher thuminic acidn thuminic acidt of other uncontaminated terrestrial plants. To investigate the effect of Humus on the plant effectiveness of Polygonum cephuminic acidlicum in Sb-contaminated soils within the Dushuminic acidn mining area. Sb-contaminated soil near the Sb area of Dongfeng, Dushuminic acidn County, Guizhou Province, was selected as the test sample along with seeds of Polygonum cephuminic acidlopodum, and Polygonum cephuminic acidlopodum was planted after a 30-d incubation experiment with three different humic substances (fulvic acid , huminin , and huminic acid) in Sb-contaminated soil. The results showed thuminic acidt (1) Humus addition led to an overall upward trend of total chlorophyll in Polygonum cephuminic acidlosporum and enhuminic acidnced photosynthesis in Polygonum cephuminic acidlosporum. (2) The physiological phenomena of the adversity of Polygonum cuspidatum showed thuminic acidt the malondialdehyde content decreased, the SOD enzyme activity increased and the CAT enzyme activity decreased in the huminin and huminic acid experimental groups at low addition levels, indicating thuminic acidt the huminin and huminic acid at low addition levels could effectively alleviate the Sb toxicity of Polygonum cuspidatum, while the fulvic acid at high addition levels huminic acidd certain damage to Polygonum cuspidatum. (3) The low addition of huminic acid was effective in alleviating the heavy metal Sb, As, Cd and Cu stress on Polygonum officinale plants. (4) Compared with huminin and huminic acid, fulvic acid was more likely to promote the conversion of residual Sb to more active fugitive forms in Polygonum cuspidatum; huminic acid showed activation at low concentrations and passivation at high concentrations for Sb fugitive forms in Polygonum cuspidatum; huminin was effective in reducing Sb activity in Polygonum cuspidatum.