PDF(Pubmed)
Abstract：
The impact of cadmium (Cd) and fluorine (F) on plant and human health has provoked significant public concern; however, their combined effects on plant and soil bacterial communities have yet to be determined. Here, a pot experiment was conducted to evaluate the effects of exogenous F, Cd, and their combination (FCd) on lettuce growth and soil bacterial communities. The results revealed that F and Cd concentrations in lettuce ranged from 63.69 to 219.45 mg kg-1 and 1.85 to 33.08 mg kg-1, respectively, presenting lower values in shoots than in the roots. Moreover, low contamination levels had no discernable influence on lettuce growth, but showed a synergistic negative on plant biomass when exogenous F and Cd exceeds 300 and 1.0 mg kg-1, respectively. The results of 16S rRNA gene sequencing indicated that the most abundant bacterial community at the phylum level was Proteobacteria, with the relative abundance ranging from 33.42% to 44.10% across all the treatments. The contaminants had little effect on bacterial richness but impacted the structure of bacterial communities. The PCoA showed that compartment and contaminants were the primary contributors to the largest source of community variation, while the VPA indicated that F and Cd synergistically affected the bacterial communities. In turn, lettuce plants could enhance the resistance to the combined stress by increasing the relative abundance of Oxyphotobacteria, Subgroup 6, Thermoleophilia, and TK10 classes in the rhizosphere.
摘要：
镉（Cd）和氟（F）对植物和人类健康的影响引起了公众的极大关注；它们对植物和土壤细菌群落的综合影响尚未确定。这里,进行了盆栽实验以评估外源F，Cd,及其组合(FCd)对莴苣生长和土壤细菌群落的影响。结果表明，莴苣中的F和Cd浓度分别为63.69至219.45mgkg-1和1.85至33.08mgkg-1，在芽中表现出比在根中更低的值。此外，低污染水平对莴苣的生长没有明显的影响，但当外源F和Cd分别超过300和1.0mgkg-1时，对植物生物量表现出协同作用。16SrRNA基因测序结果表明，门水平上最丰富的细菌群落是变形杆菌，在所有处理中，相对丰度在33.42%至44.10%之间。污染物对细菌丰富度影响不大，但影响细菌群落结构。PCoA表明，隔室和污染物是最大的群落变异源的主要贡献者，而VPA表明F和Cd协同影响细菌群落。反过来,莴苣植物可以通过增加氧化细菌的相对丰度来增强对联合胁迫的抵抗力，第6亚组，嗜热病，和根际的TK10类。
