Enzymes in the soil are vital for assessing heavy metal soil pollution. Although the presence of heavy metals is thought to change the soil enzyme system, the distribution of enzyme activities in heavy metal polluted-soil is still unknown. For the first time, using soil zymography, we analyzed the distribution of enzyme activities of alfalfa rhizosphere and soil surface in the metal-contaminated soil. The results showed that the growth of alfalfa was significantly inhibited, and an impact that was most pronounced in seedling biomass and chlorophyll content. Catalase activity (CAT) in alfalfa decreased with increasing heavy metal concentrations, while malondialdehyde (MDA) content continually increased. The distribution of enzyme activities showed that both phosphatase and β-glucosidase activities were associated with the roots and were rarely distributed throughout the soil. In addition, the total hotspot areas of enzyme activities were the highest in extremely heavy pollution soil. The hotspot areas of phosphatase were 3.4%, 1.5% and 7.1% under none, moderate and extremely heavy pollution treatment, respectively, but increased from 0.1% to 0.9% for β-glucosidase with the increasing pollution levels. Compared with the traditional method of enzyme activities, zymography can directly and accurately reflect the distribution and extent of enzyme activity in heavy metals polluted soil. The results provide an efficient research method for exploring the interaction between enzyme activities and plant rhizosphere.

土壤中的酶对于评估重金属土壤污染至关重要。尽管人们认为重金属的存在会改变土壤酶系统，但仍不清楚重金属污染土壤中酶活性的分布。首次使用土壤酶谱分析技术，分析了金属污染土壤中苜蓿根际和土壤表面酶活性的分布。结果表明，苜蓿的生长受到显着抑制，并且对幼苗生物量和叶绿素含量的影响最为明显。紫花苜蓿中的过氧化氢酶活性（CAT）随着重金属浓度的增加而降低，而丙二醛（MDA）含量持续增加。酶活性的分布表明，磷酸酶和β-葡萄糖苷酶的活性均与根相关，很少在整个土壤中分布。另外，在极重污染的土壤中，酶活性的总热点面积最高。在无，中度和极重度污染处理下，磷酸酶的热点面积分别为3.4％，1.5％和7.1％，但随着污染水平的升高，β-葡萄糖苷酶的热点面积从0.1％增加至0.9％。与传统的酶活性方法相比，酶谱法可以直接，准确地反映出重金属污染土壤中酶活性的分布和程度。该结果为探索酶活性与植物根际之间的相互作用提供了一种有效的研究方法。在极重污染的土壤中，酶活性的总热点面积最高。在无，中度和极重度污染处理下，磷酸酶的热点面积分别为3.4％，1.5％和7.1％，但随着污染水平的升高，β-葡萄糖苷酶的热点面积从0.1％增加至0.9％。与传统的酶活性方法相比，酶谱法可以直接，准确地反映出重金属污染土壤中酶活性的分布和程度。该结果为探索酶活性与植物根际之间的相互作用提供了一种有效的研究方法。在极重污染的土壤中，酶活性的总热点面积最高。在无，中度和极重度污染处理下，磷酸酶的热点面积分别为3.4％，1.5％和7.1％，但随着污染水平的升高，β-葡萄糖苷酶的热点面积从0.1％增加至0.9％。与传统的酶活性方法相比，酶谱法可以直接，准确地反映出重金属污染土壤中酶活性的分布和程度。该结果为探索酶活性与植物根际之间的相互作用提供了一种有效的研究方法。但随着污染水平的提高，β-葡萄糖苷酶的含量从0.1％增加到0.9％。与传统的酶活性方法相比，酶谱法可以直接，准确地反映出重金属污染土壤中酶活性的分布和程度。该结果为探索酶活性与植物根际之间的相互作用提供了一种有效的研究方法。但随着污染水平的提高，β-葡萄糖苷酶的含量从0.1％增加到0.9％。与传统的酶活性方法相比，酶谱法可以直接，准确地反映出重金属污染土壤中酶活性的分布和程度。该结果为探索酶活性与植物根际之间的相互作用提供了一种有效的研究方法。