Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China.
Environ Sci Pollut Res Int. 2012 Mar;19(3):893-902. doi: 10.1007/s11356-011-0625-y. Epub 2011 Oct 1.
Cuttings and seedlings of Jatropha curcas L. were exposed to different regimes of lead (Pb) stress as Pb(NO₃)₂ at 0 (CK), 0.5, 1, 2, 3, and 4 mM kg⁻¹ soil.
The effect of Pb treatment on the root length, tolerance index, photosynthetic pigments, photosynthetic activity, lipid peroxidation, and antioxidant enzyme was studied in a greenhouse pot experiment.
The results showed that root lengths and tolerance index decreased with increase of Pb concentration, but tolerance index of cuttings was always lower than those of the seedlings. For cuttings, Pb treatment had a stimulating effect on chlorophyll content, carotenoid content, and superoxide dismutase (SOD) activity at low concentration and an inhibitory effect at higher concentration. For seedlings, SOD activity increased with increasing Pb concentration. In both seedlings and cuttings, Pb caused inhibition of leaf growth and photosynthesis, and induced the membrane damage which was more obvious in the cuttings. In comparison with the control, the dynamic tendency of catalase and perxidase activities in the leaves of Pb-stressed plants all ascended, and then declined.
The increase in enzyme activities demonstrated that seedlings were more tolerant to Pb stress than cuttings. These results also indicate that the antioxidant system may play an important role in eliminating or alleviating the toxicity of Pb in J. curcas seedlings and cuttings. The accumulation of Pb increased in a concentration-dependent manner; however, its translocation from root to shoot was low. The cuttings accumulated significantly higher Pb in roots than seedlings.
利用不同浓度的硝酸铅（Pb(NO₃)₂）（0、0.5、1、2、3 和 4 mM kg⁻¹土壤）对麻疯树（Jatropha curcas L.）插条和幼苗进行胁迫处理。
通过温室盆栽试验研究 Pb 处理对麻疯树根长、耐胁迫指数、光合色素、光合活性、脂质过氧化和抗氧化酶的影响。
结果表明，根长和耐胁迫指数随 Pb 浓度的增加而降低，但插条的耐胁迫指数始终低于幼苗。对于插条，低浓度 Pb 处理对叶绿素含量、类胡萝卜素含量和超氧化物歧化酶（SOD）活性有刺激作用，而高浓度则有抑制作用。对于幼苗，SOD 活性随 Pb 浓度的增加而增加。在幼苗和插条中，Pb 均抑制叶片生长和光合作用，并诱导膜损伤，在插条中更为明显。与对照相比，受 Pb 胁迫的植物叶片中过氧化氢酶和过氧化物酶活性的动态趋势均先上升后下降。
酶活性的增加表明，幼苗比插条更能耐受 Pb 胁迫。这些结果还表明，抗氧化系统可能在消除或减轻麻疯树幼苗和插条中 Pb 的毒性方面发挥重要作用。Pb 积累量随浓度的增加呈浓度依赖性增加，但从根到地上部分的转运量较低。插条根部积累的 Pb 显著高于幼苗。
