Biotechnology Division, Institute of Himalayan Bioresource Technology, Palampur, (H.P.), India.
Int J Phytoremediation. 2012 Jan;14(1):1-13. doi: 10.1080/15226514.2011.555799.
Plants of Indian mustard (Brassica juncea L.) were exposed to different concentrations (15, 30, 60, 120 microM) of (Cd, Cr, Cu, Pb) for 28 and 56 d for accumulation and detoxification studies. Metal accumulation in roots and shoots were analyzed and it was observed that roots accumulated a significant amount of Cd (1980 microg g(-1) dry weight), Cr (1540 microg g(-1) dry weight), Cu (1995 microg g(-1) dry weight), and Pb (2040 microg g(-1) dry weight) after 56 d of exposure, though in shoot this was 1110, 618, 795, and 409 microg g(-1) dry weight of Cd, Cr, Cu, and Pb, respectively. In order to assess detoxification mechanisms, non-protein thiols (NP-SH), glutathione (GSH) and phytochelatins (PCs) were analyzed in plants. An increase in the quantity of NP-SH (9.55), GSH (8.30), and PCs (1.25) micromol g(-1) FW were found at 15 microM of Cd, however, a gradual decline in quantity was observed from 15 microM of Cd onwards, after 56 d of exposure. For genotoxicity in plants, cytogenetic end-points such as mitotic index (MI), micronucleus formation (MN), mitotic aberrations (MA) and chromosome aberrations (CA) were examined in root meristem cells of B. juncea. Exposure of Cd revealed a significant (P < 0.05) inhibition of MI, induction of MA, CA, and MN in the root tips for 24 h. However, cells examined at 24 h post-exposure showed concentration-wise recovery in all the endpoints. The data revealed that Indian mustard could be used as a potential accumulator of Cd, Cr, Cu, and Pb due to a good tolerance mechanisms provided by combined/concerted action of NP-SH, GSH, and PCs. Also, exposure of Cd can cause genotoxic effects in B. juncea L. through chromosomal mutations, MA, and MN formation.
将印度芥菜（芸薹属植物）暴露于不同浓度（15、30、60、120μM）的（Cd、Cr、Cu、Pb）中 28 和 56 天以进行积累和解毒研究。分析了根部和茎部的金属积累情况，结果表明，根部在暴露 56 天后积累了大量的 Cd（1980μg g(-1)干重）、Cr（1540μg g(-1)干重）、Cu（1995μg g(-1)干重）和 Pb（2040μg g(-1)干重），而在茎部，Cd、Cr、Cu 和 Pb 的含量分别为 1110、618、795 和 409μg g(-1)干重。为了评估解毒机制，分析了非蛋白巯基（NP-SH）、谷胱甘肽（GSH）和植物螯合肽（PCs）。在 15μM 的 Cd 下，发现 NP-SH（9.55）、GSH（8.30）和 PCs（1.25）µmol g(-1)FW 的数量增加，然而，在 56 天的暴露后，从 15μM 的 Cd 开始，数量逐渐减少。对于植物的遗传毒性，在芸薹属植物的根分生细胞中检查了细胞遗传学终点，如有丝分裂指数（MI）、微核形成（MN）、有丝分裂异常（MA）和染色体异常（CA）。Cd 的暴露导致 MI 显著（P < 0.05）抑制，根尖的 MA、CA 和 MN 诱导。然而，在暴露后 24 小时检查的细胞在所有终点都表现出浓度依赖性的恢复。数据表明，由于 NP-SH、GSH 和 PCs 的联合/协同作用提供了良好的耐受机制，印度芥菜可以作为 Cd、Cr、Cu 和 Pb 的潜在积累者。此外，Cd 的暴露会通过染色体突变、MA 和 MN 形成在芸薹属植物中引起遗传毒性效应。
