Abstract：
To screen environmentally friendly and efficient Cd pollution remediation material, the effects of BC and BF on soil Cd bio-availability and cotton Cd absorption were analyzed under Cd exposure. Besides, the differences in metabolic mechanisms by which biochar (BC) and biofertilizer (BF) affect Cd-contaminated soil and cotton were also analyzed. The results showed that the application of BC and BF increased cotton dry matter accumulation, boll number, and single boll weight, and reduced the Cd content in cotton roots, stems, leaves, and bolls. At harvest, the Cd content in cotton roots in the BC and BF groups reduced by 15.23% and 16.33%, respectively, compared with that in the control. This was attributed to the conversion of carbonate-bound Cd (carbon-Cd) and exchangeable Cd (EX-Cd) by BC and BF into residual Cd (Res-Cd). It should be noted that the soil available Cd (Ava-Cd) content in the BF group was lower than that in the BC group. The metabolomic analysis results showed that for BC vs BF, the relative abundance of differential metabolites Caffeic acid, Xanthurenic acid, and Shikimic acid in soil and cotton roots were up-regulated. Mantel test found that cotton root exudate l-Histinine was correlated with the enrichment of Cd in various organs of cotton. Therefore, the application of BC and BF can alleviate Cd stress by reducing soil Ava-Cd content and cotton\'s Cd uptake, and BF is superior to BC in reducing Cd content in soil and cotton organs. This study will provide a reference for the development of efficient techniques for the remediation of Cd-polluted alkaline soil, and provide a basis for subsequent metagenomics analysis.
摘要：
筛选环保高效Cd污染修复材料,分析了Cd暴露条件下BC和BF对土壤Cd生物有效性和棉花Cd吸收的影响。此外,还分析了生物炭（BC）和生物肥料（BF）影响Cd污染土壤和棉花的代谢机制的差异。结果表明，施用BC和BF增加了棉花干物质积累，棉铃号,和单棉铃重量，降低了棉花根中的Cd含量，茎,叶子,还有Bolls.在收获的时候，BC和BF组棉花根中Cd含量分别降低了15.23%和16.33%,分别,与控制相比。这归因于BC和BF将碳酸盐结合的Cd（碳Cd）和可交换Cd（EX-Cd）转化为残留Cd（Res-Cd）。应当指出，BF组土壤有效Cd(Ava-Cd)含量低于BC组。代谢组学分析结果表明，对于BC和BF，差异代谢产物咖啡酸的相对丰度，Xanthurenicacid,土壤和棉花根系中的莽草酸表达上调。Mantel检验发现，棉花根系渗出液l-Histinine与棉花各器官中Cd的富集有关。因此,施用BC和BF可以通过降低土壤Ava-Cd含量和棉花对Cd的吸收来缓解Cd胁迫,在降低土壤和棉花器官中Cd含量方面，BF优于BC。本研究将为开发高效的Cd污染碱性土壤修复技术提供参考,并为后续的宏基因组学分析提供依据。
