Wang Baichun, Zhu Sixi, Li Wujiang, Tang Qian, Luo Hongyu
College of Eco-environment Engineering, Guizhou Minzu University, Guiyang 550025, China; Institute of Karst Wetland Ecology, Guizhou Minzu University, Guiyang 550025, China.
College of Eco-environment Engineering, Guizhou Minzu University, Guiyang 550025, China; Institute of Karst Wetland Ecology, Guizhou Minzu University, Guiyang 550025, China.
Ecotoxicol Environ Saf. 2021 Apr 29;218:112253. doi: 10.1016/j.ecoenv.2021.112253.
Wetland plants are often used as the main body of soil, and the rhizosphere is a hot spot migration and transformation. Response mechanism to rhizosphere microorganisms on chromium(Cr) stressing could help improve the phytoremediation system. Cyperus alternifolius(CA) is selected as the research object by Cr-stress treatments and uncontaminated treatments with different cultivated pattern, included sole cultivated pattern(CAI), two-cultivated pattern (CAII), three-cultivated pattern (CAIII), and the un-planted blank samples (CK). 16s rRNA gene sequencing and metagenomic sequencing are performed to measure rhizosphere microbial community. And Five common enzymes in rhizosphere soils were observed: β-1,4-glucosidase (BG), β-N-acetylglucosaminidase (NAG), β-1,4-xylosidase (BX), cellobiohydrolase (CBH) and Leucine amino peptidase (LAP) in the rhizosphere. The results show that Gammaproteobacteria, Actinobacteria, Alphaproteobacteria, Gemmatimonadetes, Deltaproteobacteria are top five (63.97%) of the total sequence number. Wetland plants enriched a large amount of soil Cr in themselves, and the rhizosphere microorganisms don't show significant difference in community structure after affecting. 10.48% variation of microbial community is caused by Cr-stress. Acidovorax showed a great potential for chromium resistance. BX involvement in tolerance processes indirectly affects microbial communities (P < 0.01), there is a strong linear relationship between enzyme activity and the plants accumulating Cr and microbial community within 15.58% variant. The material accumulation and microbial quantity of CAIII are relatively low, but high biodiversity remains after affecting. These results provide references for in-depth understanding of rhizosphere microbial response to heavy metal pollution in wetland phytoremediation and interaction between wetland plants and rhizosphere microorganisms.
湿地植物常被用作土壤主体，根际是热点迁移和转化区域。根际微生物对铬（Cr）胁迫的响应机制有助于改善植物修复系统。通过不同栽培模式的Cr胁迫处理和未受污染处理，选择风车草（CA）作为研究对象，包括单作模式（CAI）、间作模式（CAII）、混作模式（CAIII）以及未种植的空白样本（CK）。进行16s rRNA基因测序和宏基因组测序以测定根际微生物群落。并观察了根际土壤中的五种常见酶：β-1,4-葡萄糖苷酶（BG）、β-N-乙酰氨基葡萄糖苷酶（NAG）、β-1,4-木糖苷酶（BX）、纤维二糖水解酶（CBH）和亮氨酸氨肽酶（LAP）。结果表明，γ-变形菌纲、放线菌纲、α-变形菌纲、芽单胞菌门、δ-变形菌纲占总序列数的前五位（63.97%）。湿地植物自身富集了大量土壤Cr，根际微生物群落结构受影响后无显著差异。微生物群落10.48%的变异是由Cr胁迫引起的。嗜酸菌显示出很强的抗铬潜力。BX参与耐受过程间接影响微生物群落（P < 0.01），酶活性与植物积累Cr和微生物群落之间在15.58%的变异范围内存在很强的线性关系。CAIII的物质积累和微生物数量相对较低，但受影响后仍保持较高的生物多样性。这些结果为深入了解湿地植物修复中根际微生物对重金属污染的响应以及湿地植物与根际微生物之间的相互作用提供了参考。
