The effects of lead toxicity were studied in the leaves of two barley cultivars. Plants were grown for 32 days in perlite and then exposed to 10- and 15-mM Pb(NO₃)₂ for additional 6 days. Lead toxicity decreased the photosynthetic pigment contents in the leaves of Tokak 157/37. The phenolic content of the leaves was reduced in Tarm-92 and increased in Tokak 157/37. The malondialdehyde content in leaves showed that lipid peroxidation in Tokak 157/37 was lower than in Tarm-92. H2O2 accumulation was more remarkable in the leaves of Tokak 157/37 exposed to 15 mM lead. Significantly higher superoxide dismutase activity observed in our study indicates a likely higher rate of superoxide radical dismutation. Lower ascorbate peroxidase activities were observed at 10 mM lead in Tarm-92 and at 15 mM lead in Tokak 157/37. The glutathione reductase activity in Tarm-92 was lower whereas it was induced by 10 mM lead treatment in Tokak 157/37. Lead toxicity resulted in increased level of the guaiacol peroxidase activity in both cultivars. Our results suggest that lead toxicity induced membrane damage in barley leaves, led to photosynthetic pigment loss and that guaiacol peroxidase activity may be critical for lead tolerance at early stage of seedling oxidative stress development.

在两个大麦品种的叶片中研究了铅毒性的影响。使植物在珍珠岩中生长32天，然后暴露于10-和15-mM Pb（NO ₃）₂再增加6天。铅的毒性降低了Tokak 157/37叶片中光合色素的含量。在Tar​​m-92中，叶片的酚含量降低，在Tokak 157/37中则增加。叶片中的丙二醛含量表明Tokak 157/37中的脂质过氧化作用低于Tarm-92中的。在暴露于15 mM铅的Tokak 157/37叶片中，H2O2的积累更为明显。在我们的研究中观察到明显更高的超氧化物歧化酶活性表明超氧化物自由基歧化的可能性可能更高。在Tar​​m-92中铅含量为10 mM，在Tokak 157/37中铅含量为15 mM时，抗坏血酸过氧化物酶活性较低。Tarm-92中的谷胱甘肽还原酶活性较低，而在Tokak 157/37中由10 mM铅处理诱导。铅中毒导致两个品种中愈创木酚过氧化物酶活性的水平提高。我们的结果表明，铅毒性导致大麦叶片的膜损伤，导致光合色素损失，愈创木酚过氧化物酶的活性可能对幼苗氧化胁迫发展的早期阶段的铅耐受性至关重要。