外源钙对镉胁迫下苎麻生长及生理代谢的影响

以苎麻为实验材料,采取营养液栽培方式,研究了不同浓度的钙(0、1、5和10 mmol·L-1)在5 mg·L-1 氯化镉胁迫下,对苎麻幼苗生长及植物体内重金属的积累、光合作用、抗氧化作用等的影响。研究结果显示,中浓度钙处理(5 mmol·L-1)能明显缓解镉胁迫对苎麻的毒害作用。与单独镉处理相比,外源5 mmol·L-1钙处理苎麻地上部分和根部的生物量分别为单独镉胁迫下的1.21倍和1.32倍,叶绿素含量增加了19.77%,丙二醛和过氧化氢含量分别下降了19.09%和29.02%,抗氧化酶的活性也发生了相应变化;低浓度钙处理(1 mmol·L-1)显著提高了苎麻茎叶中镉的含量,分别为单独镉胁迫下的2.54倍和3.59倍。由此表明,外源钙和镉的交互作用与外源钙的浓度密切相关。

Effects of exogenous calcium on plant growth and physiological metabolism of Boehmeria nivea(L.) Gaudich under cadmium stress

Hydroponics experiments were performed to investigate the effects of exogenous calcium(0,1,5,and 10 mmol·L-1) on the growth,metal accumulation,photosynthesis,and anti-oxygenation of Boehmeria nivea(L.) Gaudich(commonly known as ramie) under cadmium chloride stress.The results indicated that an intermediate level(5 mmol·L-1) of calcium(Ca) treatment significantly alleviated cadmium(Cd) toxicity.The dry weights of aboveground parts and roots under the treatment of 5 mmol·L-1 Ca were 1.21 and 1.32 fold than that of the only Cd treated plants,respectively.Furthermore,we found that the chlorophyll content increased by 19.77%;that the concentration of malondialdehyde(MDA) and H2O2 decreased by 19.09% and 29.02%,respectively,under the 5 mmol·L-1 Ca treatment;and that the activities of antioxidant enzymes were also changed.In addition,the lowest level of Ca(1 mmol·L-1) significantly enhanced the accumulation of Cd,and the concentrations of Cd were 2.54 and 3.59 fold the amount found in the stems and leaves of the only Cd treated plants.Overall,the interactions between Ca and Cd were closely linked to the concentration of exogenous Ca.