College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310018, China.
Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou, 310015, China.
Environ Pollut. 2023 Sep 15;333:122084. doi: 10.1016/j.envpol.2023.122084. Epub 2023 Jun 23.
Heavy metal (HM) contamination is an environmental concern that threatens the agricultural product safety and human health. To address this concern, we developed a novel strategy involving the synergistic application of Azospirillum brasilense, a growth-promoting rhizobacterium which produces abscisic acid (ABA), and biochar to minimize HM accumulation in the edible parts of vegetable crops. Compared to A. brasilense or biochar alone, the concentrations of Cd, Ni, Pb, and Zn in radish (Raphanus sativus L.), pakchoi (Brassica chinensis L.), and tomato (Lycopersicon esculentum L.) decreased by 18-63% and 14-56%, respectively. Additionally, the synergistic treatment led to a 14-63% decrease in the bioconcentration factor. The biomass of the edible parts of the three crops increased by 65-278% after synergistic treatment, surpassing the effects of single treatments. Furthermore, the synergistic application enhanced the SPAD values by 1-45% compared to single treatments. The MDA concentrations in stressed plants decreased by 16-39% with the bacteria-biochar co-treatment compared to single treatments. Co-treatment also resulted in increased soluble protein and sugar concentrations by 8-174%, and improvements in flavonoids, total phenols, ascorbic acid, and DPPH levels by 2-50%. Pearson correlation analysis and structural equation modeling revealed that the synergistic effect was attributed to the enhanced growth of A. brasilense facilitated by biochar and the improved availability of HMs in soils. Notably, although ABA concentrations were not as high as those achieved with A. brasilense alone, they were maintained at relatively high levels. Overall, the synergistic application of A. brasilense-biochar might have remarkable potential for reducing the accumulation of HMs while promoting growth and improving nutritional and antioxidant qualities in tuberous, leafy, and fruit crops.
重金属（HM）污染是一个威胁农产品安全和人类健康的环境问题。为了解决这个问题，我们开发了一种新的策略，涉及联合应用促进生长的根瘤菌巴西固氮螺菌（Azospirillum brasilense）和生物炭，以最大限度地减少蔬菜作物可食用部分中 HM 的积累。与单独使用巴西固氮螺菌或生物炭相比，萝卜（Raphanus sativus L.）、白菜（Brassica chinensis L.）和番茄（Lycopersicon esculentum L.）中 Cd、Ni、Pb 和 Zn 的浓度分别降低了 18-63%和 14-56%。此外，协同处理导致生物浓缩因子降低了 14-63%。协同处理后，三种作物可食用部分的生物量增加了 65-278%，超过了单一处理的效果。此外，与单一处理相比，协同应用使 SPAD 值提高了 1-45%。与单一处理相比，细菌-生物炭协同处理使胁迫植物的 MDA 浓度降低了 16-39%。协同处理还使可溶性蛋白和糖浓度分别提高了 8-174%，并使类黄酮、总酚、抗坏血酸和 DPPH 水平提高了 2-50%。Pearson 相关分析和结构方程模型表明，协同效应归因于生物炭促进巴西固氮螺菌生长和提高土壤中 HM 可用性。值得注意的是，尽管 ABA 浓度没有单独使用巴西固氮螺菌时高，但仍保持在相对较高的水平。总的来说，巴西固氮螺菌-生物炭的协同应用可能具有显著的潜力，可以减少 HM 的积累，同时促进块茎、叶和水果作物的生长，并改善其营养和抗氧化品质。
