Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resources Science, Zhejiang University, Hangzhou, 310058, People's Republic of China.
Institute of Food and Agricultural Sciences, Indian River Research and Education Center, University of Florida, Fort Pierce, FL, 34945, USA.
Environ Sci Pollut Res Int. 2019 Jan;26(2):1809-1820. doi: 10.1007/s11356-018-3680-9. Epub 2018 Nov 19.
Plant uptake of cadmium (Cd) is affected by soil and environmental conditions. In this study, hydroponic experiments were conducted to investigate the effects of elevated CO coupled with inoculated endophytic bacteria M002 on morphological properties, gas exchange, photosynthetic pigments, chlorophyll fluorescence, and Cd uptake of S. alfredii. The results showed that bio-fortification processes (elevated CO and/or inoculated with endophytic bacteria) significantly (p < 0.05) promoted growth patterns, improved photosynthetic characteristics and increased Cd tolerance of both ecotypes of S. alfredii, as compared to normal conditions. Net photosynthetic rate (Pn) in intact leaves of hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) were increased by 73.93 and 32.90%, respectively at the low Cd (2 μM), 84.41 and 57.65%, respectively at the high Cd level (10 μM). Superposition treatment increased Cd concentration in shoots and roots of HE, by 50.87 and 82.12%, respectively at the low Cd and 46.75 and 88.92%, respectively at the high Cd level. Besides, superposition treatment declined Cd transfer factor of NHE, by 0.85% at non-Cd rate, 17.22% at the low Cd and 22.26% at the high Cd level. These results indicate that elevated CO coupled with endophytic bacterial inoculation may effectively improve phytoremediation efficiency of Cd-contaminated soils by hyperaccumulator, and alleviate Cd toxicity to non-hyperaccumulator ecotype of Sedum alfredii.
植物对镉（Cd）的吸收受土壤和环境条件的影响。本研究通过水培实验，研究了高 CO 耦合内生细菌 M002 接种对超积累型（HE）和非超积累型（NHE）两生态型东南景天形态特性、气体交换、光合色素、叶绿素荧光和 Cd 吸收的影响。结果表明，与正常条件相比，生物强化过程（高 CO 和/或内生细菌接种）显著（p<0.05）促进了两生态型东南景天的生长模式，改善了光合特性，提高了 Cd 耐性。低 Cd（2 μM）和高 Cd（10 μM）水平下，完整叶片的净光合速率（Pn）分别在超积累型（HE）和非超积累型（NHE）中增加了 73.93%和 32.90%，84.41%和 57.65%。叠加处理分别使低 Cd 和高 Cd 水平下 HE 地上部和根部的 Cd 浓度增加了 50.87%和 82.12%，46.75%和 88.92%。此外，叠加处理使 NHE 的 Cd 转移系数在非 Cd 浓度下下降了 0.85%，在低 Cd 浓度下下降了 17.22%，在高 Cd 浓度下下降了 22.26%。这些结果表明，高 CO 耦合内生细菌接种可以有效提高超积累植物对 Cd 污染土壤的修复效率，并减轻 Cd 对非超积累型东南景天生态型的毒性。
