Excessive heavy metals in medicinal plants cause critical health issues to humans. Therefore, in the present study, the effect of soil amendment with chitosan (0, 0.125, 0.25, 0.5, and 1%) on bioavailability and tolerance of nickel in Calendula tripterocarpa grown in a soil spiked with Ni (100 and 150 mg/kg soil) was investigated. The results showed that Ni toxicity significantly reduced plant growth and content of chlorophyll a, b but increased carotenoid levels, lipid peroxidation, and catalase (CAT) and superoxide dismutase (SOD) activities in roots and shoots. The Ni bioaccumulation was significantly higher in shoots than roots. The soil amendment with chitosan reduced Ni bioavailability in soil, as well as lowered the biological accumulation of Ni in roots and shoots, and Ni transfer to leaves. The chitosan application also increased growth parameters and levels of chlorophyll a, b and carotenoids under both normal and Ni stress conditions. Furthermore, chitosan reduced the level of malondialdehyde and the activities of SOD and CAT in roots and shoots under Ni stress. In conclusion, results indicated that chitosan through lowering bioavailability of Ni in soils can remarkably relieve adverse effects of Ni toxicity in C. tripterocarpa.

药用植物中过量的重金属会给人类带来严重的健康问题。因此，在本研究中，壳聚糖（0％，0.125％，0.25％，0.5％和1％）土壤改良剂对掺有Ni（100和150 mg / kg）的土壤中金盏菊的生物利用度和镍耐受性的影响。土壤）进行了调查。结果表明，镍的毒性显着降低了植物的生长和叶绿素a，b的含量但增加了根和茎中类胡萝卜素的水平，脂质过氧化以及过氧化氢酶（CAT）和超氧化物歧化酶（SOD）的活性。芽中的镍生物累积量显着高于根部。壳聚糖对土壤的改良作用降低了土壤中Ni的生物利用度，并降低了Ni在根和芽中的生物积累，并且Ni转移到叶片中。在正常和Ni胁迫条件下，壳聚糖的施用还增加了生长参数以及叶绿素a，b和类胡萝卜素的水平。此外，壳聚糖降低了Ni胁迫下根和芽中丙二醛的含量以及SOD和CAT的活性。总之，结果表明，壳聚糖通过降低土壤中Ni的生物利用度可以显着减轻Ni的毒性。C.tripterocarpa。