Guangdong Provincial Key Laboratory of Petrochemical Pollution Processes and Control, School of Environmental Science and Engineering, Guangdong University of Petrochemical Technology, Maoming, Guangdong, 525000, China.
Department of Civil and Environmental Engineering and Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong; State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong.
Environ Pollut. 2024 Nov 15;361:124803. doi: 10.1016/j.envpol.2024.124803. Epub 2024 Aug 23.
Isodecyl diphenyl phosphate (IDDP) is among the emerging aromatic organophosphate esters (aryl-OPEs) that pose risks to both human beings and other organisms. This study aims to investigate the translocation and biotransformation behavior of IDDP in rice and the rhizosphere microbiome through hydroponic exposure (the duration of hydroponic exposure was 10 days). The rhizosphere microbiome 9-FY was found to efficiently eliminate IDDP, thereby reducing its uptake in rice tissues and mitigating the negative impact of IDDP on rice growth. Furthermore, this study proposed the first-ever transformation pathways of IDDP, identifying hydrolysis, hydroxylation, methylation, methoxylation, carboxylation, and glucuronidation products. Notably, the methylation and glycosylation pathways were exclusively observed in rice, indicating that the transformation of IDDP in rice may be more complex than in microbiome 9-FY. Additionally, the presence of the product COOH-IDDP in rice suggested that there might be an exchange of degradation products between rice and rhizobacteria, implying their potential interaction. This finding highlights the significance of rhizobacteria's role which cannot be overlooked in the accumulation and transformation of organic pollutants in grain crops. The study revealed active members in 9-FY during IDDP degradation, and metagenomic analysis indicated that most of the active populations contained IDDP-degrading genes. Moreover, transcriptome sequencing showed that cytochrome P450, acid phosphatase, glucosyltransferase, and methyltransferases genes in rice were up-regulated, which was further confirmed by RT-qPCR. This provides insight into the intermediate products identified in rice, such as hydrolysis, hydroxylated, glycosylated, and methylated products. These results significantly contribute to our understanding of the translocation and transformation of organophosphate esters (OPEs) in plants and the rhizosphere microbiome, and reveal the fate of OPEs in rice and microbiome system to ensure the paddy yield and rice safety.
异十三烷基二苯磷酸酯（IDDP）是新兴的芳香族有机磷酸酯（aryl-OPEs）之一，对人类和其他生物都构成风险。本研究旨在通过水培暴露（水培暴露持续 10 天）研究 IDDP 在水稻和根际微生物组中的迁移和生物转化行为。发现根际微生物组 9-FY 能够有效地消除 IDDP，从而减少其在水稻组织中的吸收，并减轻 IDDP 对水稻生长的负面影响。此外，本研究提出了 IDDP 的首个转化途径，鉴定出水解、羟化、甲基化、甲氧基化、羧化和葡萄糖醛酸化产物。值得注意的是，甲基化和糖基化途径仅在水稻中观察到，表明 IDDP 在水稻中的转化可能比在微生物组 9-FY 中更复杂。此外，在水稻中存在产物 COOH-IDDP 表明，水稻和根际细菌之间可能存在降解产物的交换，暗示它们可能存在相互作用。这一发现强调了根际细菌在粮食作物中有机污染物积累和转化过程中不可忽视的作用。研究揭示了 IDDP 降解过程中 9-FY 中的活性成员，宏基因组分析表明，大多数活性种群都含有 IDDP 降解基因。此外，转录组测序表明，水稻中细胞色素 P450、酸性磷酸酶、葡萄糖基转移酶和甲基转移酶基因上调，这进一步通过 RT-qPCR 得到证实。这为鉴定出的水稻中的中间产物提供了深入了解，如水解、羟化、糖基化和甲基化产物。这些结果为我们理解有机磷酸酯（OPEs）在植物和根际微生物组中的迁移和转化，以及揭示 OPEs 在水稻和微生物组系统中的命运提供了重要依据，以确保稻谷产量和稻米安全。
