Wang Xue, Zheng Wei-Long, Wu Chun-Lan, Han Jing-Jing, Xiang Yu-Peng, Yang Ming-Lang, He Peng, Yu Fei-Hai, Li Mai-He
Institute of Wetland Ecology & Clone Ecology/Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou, Zhejiang, China.
Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Sciences, Tianjin Normal University, Tianjin, China.
Front Plant Sci. 2024 Dec 12;15:1507089. doi: 10.3389/fpls.2024.1507089. eCollection 2024.
Both rhizospheric soil microbes and shoot litter input can have profound effects on plant performance; however, their interactive effects on plants in Cd-contaminated soils remain poorly understood. We grew an invasive hyperaccumulator, , in sterilized and unsterilized rhizosphere soil without litter or with a low (0.2%, dry weight ratio) or a high amount (1%) of litter from in soil with low (5 mg kg) or high (10 mg kg) concentrations of Cd. The total, shoot, and root biomass of increased significantly with litter addition, by an average of 27%, 28%, and 20%, respectively. The biomass of was significantly lower in unsterilized rhizosphere soil than in sterilized rhizosphere soil, decreasing by 19% for total, 18% for shoot, and 24% for root, respectively. Furthermore, the effects of different litter amounts (0.2% vs. 1%) on biomass did not vary in sterilized rhizosphere soils but significantly varied in unsterilized rhizosphere soils, showing that the biomass was significantly lower with 1% litter addition than with 0.2% litter addition in unsterilized rhizosphere soils, decreasing by 28% for total, 29% for shoot, and 21% for root, respectively. Tissue Cd concentrations were significantly higher in highly Cd-contaminated soils (+75% for shoot and +51% for root) than in low Cd-contaminated soils; however, higher tissue Cd concentrations did not cause a significant decrease in the biomass of . Soil fungal communities, particularly the dominant phyla, Ascomycota and Basidiomycota, play crucial roles in modulating the effects of rhizosphere soil microbes and litter on the growth of . Our results suggest that rhizosphere soil microbes and litter interact and affect the growth of : litter addition promoted growth by increasing the abundance of saprotrophs (especially Basidiomycota) and decreasing Cd accumulation in plant tissues, and rhizosphere soil inhibition was associated with a decreased abundance of Basidiomycota. Our findings highlight the importance of the interactive effects of rhizospheric soil microbes and litter on plant growth in Cd-contaminated soils.
根际土壤微生物和地上凋落物输入都可能对植物生长产生深远影响；然而，它们对镉污染土壤中植物的交互作用仍知之甚少。我们在低镉（5毫克/千克）或高镉（10毫克/千克）浓度的土壤中，在无菌和未灭菌的根际土壤中种植一种入侵性超富集植物，分别有无凋落物或添加低量（0.2%，干重比）或高量（1%）的[植物名称未给出]凋落物。添加凋落物后，[植物名称未给出]的总生物量、地上生物量和根生物量显著增加，平均分别增加27%、28%和20%。在未灭菌的根际土壤中，[植物名称未给出]的生物量显著低于灭菌根际土壤，总生物量减少19%，地上生物量减少18%，根生物量减少24%。此外，不同凋落物量（0.2%对1%）对生物量的影响在灭菌根际土壤中没有差异，但在未灭菌根际土壤中差异显著，表明在未灭菌根际土壤中添加1%凋落物时生物量显著低于添加0.2%凋落物时，总生物量减少28%，地上生物量减少29%，根生物量减少21%。高镉污染土壤中的组织镉浓度显著高于低镉污染土壤（地上部分高75%，根高51%）；然而，较高的组织镉浓度并未导致[植物名称未给出]生物量显著下降。土壤真菌群落，特别是优势门类子囊菌门和担子菌门，在调节根际土壤微生物和凋落物对[植物名称未给出]生长的影响方面发挥着关键作用。我们的结果表明，根际土壤微生物和凋落物相互作用并影响[植物名称未给出]的生长：添加凋落物通过增加腐生菌（特别是担子菌门）的丰度和减少植物组织中的镉积累促进生长，而根际土壤抑制与担子菌门丰度降低有关。我们的研究结果突出了根际土壤微生物和凋落物对镉污染土壤中植物生长的交互作用的重要性。
