State Key Laboratory of Efficient Production of Forest Resources, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, 100091, China.
State Key Laboratory of Tree Genetics and Breeding & Key Laboratory of Tree Breeding and Cultivation of State Forestry Administration, Chinese Academy of Forestry, Beijing, 100091, China.
Environ Sci Pollut Res Int. 2024 May;31(21):31590-31604. doi: 10.1007/s11356-024-33353-3. Epub 2024 Apr 19.
Phytoremediation using fast-growing woody plants assisted by plant growth-promoting bacteria (PGPB) on cadmium (Cd)-contaminated sites is considered a promising technique; however, its remediation efficiency is still affected by multiple factors. In this study, the mining areas' soil conditions were simulated with different Cd addition levels (0, 3, 6, 9 mg kg) in order to investigate the response strategy to Cd stress of fast-growing economic tree species, slash pine (Pinus elliottii), and the effects of inoculation with the PGPB strain Herbaspirillum sp. YTG72 on the physiological activity and Cd accumulation of plants. The main results showed that there were significant (p < 0.05) increases in contents of chlorophyll and nutrient elements (P, K, Ca, and Mg) at low Cd addition level (3 mg kg) compared to non-Cd addition treatment. When the additive amount of Cd increased, the growth of plants was severely inhibited and the content of proline was increased, as well as Cd in plants. Besides, the ratios of K:P, Ca:P, and Mg:P in plants were negatively correlated with the contents of Cd in plants and soils. Inoculation of P. elliottii with the PGPB strain Herbaspirillum sp. YTG72 improved the physiological functions of the plants under Cd stress and activated the antioxidant system, reduced the accumulation of proline, and decreased the ratios of K:P, Ca:P, and Mg:P in plant. More importantly, planting P. elliottii in Cd-contaminated soil could significantly (p < 0.05) reduce the Cd content in the rhizosphere soil, and furthermore, inoculation treatment could promote the reduction of soil Cd content and increased the accumulation of Cd by root. The results of the present study emphasized the Cd response mechanism of P. elliottii based on multifaceted regulation, as well as the feasibility of strain Herbaspirillum sp. YTG72 assisted P. elliottii for the remediation on Cd-contaminated sites.
利用植物促生菌（PGPB）辅助生长迅速的木本植物进行植物修复，被认为是一种很有前途的技术；然而，其修复效率仍然受到多种因素的影响。本研究通过添加不同水平的镉（0、3、6、9mg kg）来模拟矿区土壤条件，以研究速生经济树种湿地松（Pinus elliottii）对镉胁迫的响应策略，以及接种 PGPB 菌株 Herbaspirillum sp. YTG72 对植物生理活性和镉积累的影响。主要结果表明，与非镉添加处理相比，低镉添加水平（3mg kg）下，叶绿素和营养元素（P、K、Ca 和 Mg）的含量显著增加（p<0.05）。当镉添加量增加时，植物生长受到严重抑制，脯氨酸含量增加，植物中镉含量也增加。此外，植物中 K:P、Ca:P 和 Mg:P 的比值与植物和土壤中镉的含量呈负相关。接种 P. elliottii 与 PGPB 菌株 Herbaspirillum sp. YTG72 可改善植物在镉胁迫下的生理功能，激活抗氧化系统，减少脯氨酸积累，降低植物中 K:P、Ca:P 和 Mg:P 的比值。更重要的是，在镉污染土壤中种植湿地松可以显著降低根际土壤中镉的含量，而接种处理可以促进土壤中镉含量的降低和根对镉的积累。本研究结果强调了 P. elliottii 基于多方面调节的镉响应机制，以及菌株 Herbaspirillum sp. YTG72 辅助 P. elliottii 对镉污染场地修复的可行性。
