Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India.
Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India.
Ecotoxicol Environ Saf. 2014 Feb;100:105-13. doi: 10.1016/j.ecoenv.2013.09.005. Epub 2013 Nov 14.
In the present study phytoavailability of Cd, growth yield, cellular Cd accumulation and oxidative stress responses were studied in leafy vegetable Amaranthus caudatus under soil amendments. The test plant was cultivated in Cd contaminated soil (6 µgCdg(-1) soil) amended with different doses: 0.5, 2, 5 and 10 percent of rice husk (RH), saw dust (SD), farmyard manure (FYM), farmyard in combination with nitrogen, and phosphorus and potassium (FYM+NPK). Phytoavailability of Cd in amended soil and cellular Cd accumulation in edible parts (shoot) of A. caudatus declined maximally with 5 percent dose of each amendment, and decrease in Cd content in tissues was 36, 45, 23 and 14 percent under FYM, FYM+NPK, RH and SD amendments, respectively, over the value recorded in plants grown in Cd contaminated non-amended soil (Cd(+)NA soil). The shoot yield in control plant cultivated in the absence of Cd without amendment (Cd(-)NA soil) was 18.1 ± 0.98 gfwplant(-1) and it was declined up to 50 percent (9.2 ± 0.80 gfwplant(-1)) when plants were grown in Cd(+)NA soil. Amendments with 5 percent doses of FYM+NPK and FYM enhanced the yield up to 26.5 ± 0.57 and 20.5 ± 1.00 gfwplant(-1), respectively, which may be correlated with better mineral nutrients and organic carbon content in amended soil. RH and SD amendments with similar doses improved in yield up to 16.9 ± 0.43 and 15.2 ± 0.45 gfwplant(-1), respectively, however, it was still less than that of control. Further, correlation analysis of growth yield, Cd concentration and oxidative stress under these conditions suggest that with the decrease in cellular Cd concentration following amendment the level of oxidative markers (oxidants: O2(-) and H2O2 and lipid peroxidation: malondialdehyde; MDA) declined as a result of significant enhancement in the activity of enzymatic antioxidants (peroxidase, ascorbate peroxidase, superoxide dismutase, dyhydroascorbe reductase and catalase). Thus, the present technique can efficiently reduce the metal load in food chain and also increase plant yield, hence it could be applied in catchments area of urban cities where metal contamination has become an unavoidable factor.
在本研究中，通过在土壤改良剂下种植叶菜苋菜（Amaranthus caudatus）来研究 Cd 的植物可利用性、生长产量、细胞 Cd 积累和氧化应激反应。将受试植物种植在受 Cd 污染的土壤（土壤中含 6μgCd/g 土壤）中，并添加不同剂量：稻壳（RH）、锯末（SD）、农家肥（FYM）、与氮、磷和钾组合的农家肥（FYM+NPK）的 0.5%、2%、5%和 10%。添加土壤中 Cd 的植物可利用性和苋菜可食用部分（芽）中的细胞 Cd 积累量，随着每种改良剂的 5%剂量的使用而最大程度地下降，并且 FYM、FYM+NPK、RH 和 SD 改良剂处理下组织中的 Cd 含量分别比在未添加改良剂的受 Cd 污染的非添加土壤（Cd(+)NA 土壤）中生长的植物记录的值下降了 36%、45%、23%和 14%。在没有添加改良剂的情况下，在不存在 Cd 的情况下在对照植物（Cd(-)NA 土壤）中培养的芽产量为 18.1±0.98gFW/plant(-1)，当植物在 Cd(+)NA 土壤中生长时，产量下降了 50%（9.2±0.80gFW/plant(-1)）。添加 FYM+NPK 和 FYM 的 5%剂量可将产量提高至 26.5±0.57 和 20.5±1.00gFW/plant(-1)，这可能与改良土壤中更好的矿物质营养和有机碳含量有关。添加类似剂量的 RH 和 SD 可将产量提高至 16.9±0.43 和 15.2±0.45gFW/plant(-1)，然而，这仍然低于对照。此外，在这些条件下对生长产量、Cd 浓度和氧化应激的相关分析表明，随着细胞 Cd 浓度的降低，氧化标记物（氧化剂：O2(-)和 H2O2 和脂质过氧化：丙二醛；MDA）的水平下降，这是由于酶抗氧化剂（过氧化物酶、抗坏血酸过氧化物酶、超氧化物歧化酶、二氢抗坏血酸还原酶和过氧化氢酶）活性的显著增强所致。因此，该技术可有效降低食物链中的金属负荷，同时提高植物产量，因此可应用于城市集水区，那里的金属污染已成为一个不可避免的因素。
