Department of Biology, University Federal de Santa Maria, Camobi, Santa Maria, RS 97105-900, Brazil.
Bull Environ Contam Toxicol. 2011 Mar;86(3):272-7. doi: 10.1007/s00128-011-0226-y. Epub 2011 Feb 19.
Plantlets of Pfaffia glomerata (Spreng.) were exposed in vitro for 30 days to five lead levels (0-400 μM) to analyze the effects on growth and oxidative stress and responses of various antioxidants vis-à-vis lead accumulation. The plantlets showed significant lead accumulation in roots (1,532 μg g(-1) DW) with a low root to shoot lead translocation (ca. 3.6%). The growth of plantlets was negatively affected by various lead treatments, although the level of photosynthetic pigments did not alter significantly in response to any lead treatment. However, plantlets suffered from oxidative stress as suggested by the significant increase in malondialdehyde levels in root (8.48 μmol g(-1) FW) and shoot (3.20 μmol g(-1) FW) tissues with increasing lead treatments. In response to the imposed toxicity, increases in the activities of catalase in root (4.14 ∆E min(-1) mg(-1) protein) and shoot (3.46 ∆E min(-1) mg(-1) protein) and superoxide dismutase in root (345.32 units mg(-1) protein) and shoot (75.26 units mg(-1) protein), respectively, were observed, while the levels of non-protein thiols and ascorbic acid were not affected significantly in either roots or shoots.
研究了 30 天内 5 种不同浓度的铅（0-400μM）对 Pfaffia glomerata（Spreng.）丛生芽生长和氧化胁迫的影响，以及不同抗氧化剂对铅积累的响应。丛生芽根部对铅有很强的积累作用（1532μg g(-1) DW），根到茎的铅转移率（约 3.6%）较低。尽管任何铅处理都没有显著改变光合色素的水平，但各种铅处理都对丛生芽的生长有负面影响。然而，如根部（8.48μmol g(-1) FW）和茎部（3.20μmol g(-1) FW）中丙二醛含量的显著增加所表明的，丛生芽受到了氧化胁迫。为了应对毒性，根中过氧化氢酶的活性（4.14∆E min(-1) mg(-1) 蛋白）和茎中过氧化氢酶的活性（3.46∆E min(-1) mg(-1) 蛋白）分别增加，根和茎中的超氧化物歧化酶的活性（345.32 单位 mg(-1) 蛋白和 75.26 单位 mg(-1) 蛋白）也相应增加，而根部和茎部的非蛋白巯基和抗坏血酸的水平都没有显著变化。
