Liu Houjun, Zhang Chengxin, Wang Junmei, Zhou Chongjun, Feng Huan, Mahajan Manoj D, Han Xiaori
National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, College of Land and Environment, Shenyang Agricultural University, Shenyang 110866, China.
Department of Earth and Environmental Studies, Montclair State University, Montclair, NJ 07043, USA.
Chemosphere. 2017 Mar;171:240-247. doi: 10.1016/j.chemosphere.2016.12.081. Epub 2016 Dec 20.
In this study, a soil pot experiment was conducted to investigate the changes in photosynthesis and antioxidative enzymes in two rice varieties (Shendao 6 and Shennong 265) supplied with iron (Fe), cadmium (Cd), and Fe and Cd together. The concentrations of Fe and Cd in the soil were 0, 1.0 g Fe·kg and 0, 2.0 mg Cd·kg, respectively. Photosynthetic indices and antioxidative enzyme activities were recorded at different rice growth stages. At the early stage, Cd showed a transient stimulatory effect on the photosynthetic rate of Shennong 265. For Shendao 6, however, Cd showed a transient stimulatory effect on photosynthetic rate, intercellular CO concentration, stomatal conductance and transpiration efficiency. In addition, the results show that Cd can also enhance the superoxide dismutase (SOD) and peroxidase (POD) activities, but reduce the malondialdehyde (MDA) and soluble protein contents in the two rice cultivars. Subsequently, Cd starts to inhibit photosynthesis and SOD activity until the ripening stage, causing the lowest photosynthetic rate and SOD activity at this stage. In contrast, Fe alleviates the Cd-induced changes at earlier or later growth stage. Notably at the later growth stage, the results show that the interaction between Fe and Cd increases the SOD and catalase (CAT) activities, while decreasing the lipid peroxidation and promoting photosynthesis. As a result, it ultimately increases the biomass. The results from this study suggest that Fe (as Fe fertilizer) is a promising alternative for agricultural use to enhance the plant development and, simultaneously, to reduce Cd toxicity in extensively polluted soils.
在本研究中，进行了一项土培盆栽试验，以探究在供应铁（Fe）、镉（Cd）以及铁和镉共同供应的情况下，两个水稻品种（沈稻6号和神农265）光合作用和抗氧化酶的变化。土壤中铁和镉的浓度分别为0、1.0 g Fe·kg和0、2.0 mg Cd·kg。在水稻不同生长阶段记录光合指标和抗氧化酶活性。在早期，镉对神农265的光合速率表现出短暂的刺激作用。然而，对于沈稻6号，镉对光合速率、胞间CO浓度、气孔导度和蒸腾效率表现出短暂的刺激作用。此外，结果表明，镉还可提高两个水稻品种的超氧化物歧化酶（SOD）和过氧化物酶（POD）活性，但降低丙二醛（MDA）和可溶性蛋白含量。随后，镉开始抑制光合作用和SOD活性，直至成熟阶段，导致该阶段光合速率和SOD活性最低。相比之下，铁在生长早期或后期缓解了镉诱导的变化。值得注意的是在生长后期，结果表明铁和镉之间的相互作用增加了SOD和过氧化氢酶（CAT）活性，同时降低了脂质过氧化并促进了光合作用。结果，最终增加了生物量。本研究结果表明，铁（作为铁肥）是一种有前景的农业替代品，可促进植物生长，同时降低重金属污染土壤中镉的毒性。
