Zhu Cui-Lan, Lü Hui-Xiong, Huang Yu-Hong, Cheng Ji-Liang, Li Hui, Li Yan-Wen, Mo Ce-Hui, Zhao Hai-Ming, Xiang Lei, Cai Quan-Ying
Guangdong Provincial Research Center for Environment Pollution Control and Remediation Materials, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
J Hazard Mater. 2023 Jun 15;452:131227. doi: 10.1016/j.jhazmat.2023.131227. Epub 2023 Mar 29.
Organic pollutants influenced root-associated bacterial community. However, the response variation of root-associated bacterial community among different rice genotypes exposed to phthalates (PAEs) and their removal mechanism remains unknown. Here, bacterial community and PAE-degrading genes in root-associated niches were analyzed between low (Fengyousimiao) and high (Hhang) PAE-accumulating rice cultivars exposed to di-(2-ethylhexyl) phthalate (DEHP). DEHP dissipation percentages in rhizosphere of Hhang were significantly higher than those of Fengyousimiao. The bacterial community diversities (including Chao1 and Shannon index) significantly decreased along bulk soil - rhizosphere - rhizoplane - endosphere. The bacterial community structures were shaped mainly by root-associated niches, DEHP pollution and rice genotypes, with significant differences in rhizosphere and rhizoplane between Fengyousimiao and Hhang. Rhizosphere enriched more PAE-degrading bacteria than in bulk soil, and exhibited significantly higher expression of PAE-degrading genes (hydrolase 65, phtab, phtC, pcaF and pcaI) than in bulk soil. Furthermore, rhizosphere of Hhang demonstrated significantly stronger bacterial functions related to xenobiotics biodegradation and higher expression of PAE-degrading genes than those of Fengyousimiao, leading to significantly higher DEHP dissipation percentages in rhizosphere of Hhang. The findings demonstrate that Hhang shaped specific root-associated bacterial community with higher abundances of PAE-degrading bacteria and genes than Fengyousimiao to promote DEHP degradation.
有机污染物会影响根系相关细菌群落。然而，不同水稻基因型在接触邻苯二甲酸酯（PAEs）时根系相关细菌群落的响应变化及其去除机制仍不清楚。在此，对低PAE积累水稻品种（丰优丝苗）和高PAE积累水稻品种（航）在接触邻苯二甲酸二（2-乙基己基）酯（DEHP）时根系相关微环境中的细菌群落和PAE降解基因进行了分析。航的根际中DEHP的消散百分比显著高于丰优丝苗。细菌群落多样性（包括Chao1和香农指数）沿土壤本体-根际-根表-内生菌显著降低。细菌群落结构主要由根系相关微环境、DEHP污染和水稻基因型决定，丰优丝苗和航在根际和根表存在显著差异。根际比土壤本体富集了更多的PAE降解细菌，并且PAE降解基因（水解酶65、phtab、phtC、pcaF和pcaI）的表达显著高于土壤本体。此外，航的根际显示出与异源生物降解相关的细菌功能显著更强，且PAE降解基因的表达高于丰优丝苗，导致航的根际中DEHP消散百分比显著更高。研究结果表明，航形成了特定的根系相关细菌群落，其PAE降解细菌和基因的丰度高于丰优丝苗，从而促进了DEHP的降解。
