Hainan Key Laboratory for Sustainable Utilization of Tropical Bioresources, College of Tropical Crops, Hainan University, Haikou, Hainan 570228, China.
College of Food Science and Engineering, Hainan University, Haikou, Hainan 570228, China.
J Hazard Mater. 2021 Jun 5;411:125143. doi: 10.1016/j.jhazmat.2021.125143. Epub 2021 Jan 14.
The most common environmental pollutants such as cadmium (Cd), glyphosate and tetracycline have led to profoundly adverse impacts on plant productivity. However, how tropical crops such as cassava sense these pollutants via roots and how rhizosphere microbiome interacts with the host and pollutants remain largely unknown. In this study, we found these stresses significantly inhibited plant growth and triggered cell damage in a dosage-dependent manner, and the toxic effect on redox homeostasis was correlated with antioxidant metabolism. Using metagenomics technique, we found the rhizosphere microbiomes dynamically altered as the dose of these stresses increased. We also identified stressor-associated metagenome-assembled genomes and microbial metabolic pathways as well as mobile genetic elements in the rhizosphere microbiomes. Next, a co-occurrence network of both physiological and microbiome features was constructed to explore how these pollutants derived oxidative damage through the microbiome succession. Notably, phyllosphere transplantation of Agrobacterium tumefaciens or Pseudomonas stutzeri can significantly alleviate the negative effects of stresses on cassava growth and redox homeostasis. Collectively, this study demonstrated the dynamics of rhizosphere bacterial microbiome of cassava under three common environmental stresses, and A. tumefaciens and P. stutzeri could be developed as potential beneficial bacteria to alleviate Cd, glyphosate and tetracycline-triggered damage to cassava.
最常见的环境污染物，如镉（Cd）、草甘膦和四环素，对植物生产力造成了深远的不利影响。然而，木薯等热带作物如何通过根部感知这些污染物，以及根际微生物组如何与宿主和污染物相互作用，在很大程度上仍然未知。在这项研究中，我们发现这些胁迫因素以剂量依赖的方式显著抑制了植物的生长并引发了细胞损伤，而对氧化还原平衡的毒性作用与抗氧化代谢有关。使用宏基因组学技术，我们发现随着这些胁迫因素剂量的增加，根际微生物组发生了动态变化。我们还鉴定了与胁迫相关的宏基因组组装基因组和微生物代谢途径以及根际微生物组中的移动遗传元件。接下来，构建了生理和微生物组特征的共现网络，以探讨这些污染物如何通过微生物组演替产生氧化损伤。值得注意的是，根际土壤中根瘤农杆菌或施氏假单胞菌的叶际移植可以显著减轻胁迫对木薯生长和氧化还原平衡的负面影响。总之，本研究展示了三种常见环境胁迫下木薯根际细菌微生物组的动态变化，并且根瘤农杆菌和施氏假单胞菌可以开发为潜在的有益细菌，以减轻 Cd、草甘膦和四环素对木薯的损伤。
