Han Ailiang, Yue Ling, Li Zheng, Wang Haiyan, Wang Yue, Ye Qingfu, Lu Long, Gan Jay
Institute of Nuclear-Agricultural Sciences, Key Laboratory of Nuclear Agricultural Sciences of Ministry of Agriculture and Zhejiang Province, Zhejiang University, Hangzhou, Zhejiang 310029, China.
Chemosphere. 2009 Nov;77(7):955-61. doi: 10.1016/j.chemosphere.2009.08.008. Epub 2009 Sep 3.
The plant availability and phytotoxicity of soil bound residues (BR) of herbicide ZJ0273, a novel acetolactate synthase (ALS) potential inhibitor, to rice (Oryza sativa L.) and corn (Zea mays L.) was investigated in three different soils including a Fluvio-marine yellow loamy soil (S(1)), a Red clayey soil (S(2)), and a Coastal saline soil (S(3)), using (14)C-labeling tracer and bioassay techniques. When soils were amended with BR at 0.6, 1.2 and 1.8 nmol g(-1), dose-dependent and significant inhibition was observed for rice seedlings within 14d after treatment, but no significant inhibition occurred to corn seedlings in the same treatment. Radioactive analysis of soil extracts following sequential extractions showed that the (14)C labeled residues of ZJ0273 were released from the amended soil BR upon planting. For example, when amended with 1.8 nmol g(-1), about 68.3%, 57.0%, and 61.1%, respectively, of the added BR were released in S(1), S(2), and S(3) planted with rice seedlings, whereas 38.9%, 32.7% and 32.6% became available for uptake in the corresponding soils planted with corn seedlings. The released compounds were identified as ZJ0273 and its degradation products M1 and M2, with M2 as the primary component. Bioassay on rice showed that concentration for 50% inhibition (IC(50)) of ZJ0273, M1, and M2 were 33.16, 1.93 and 0.49 microM, respectively. Therefore, BR formed after application of ZJ0273 may become available for plant uptake during rice cultivation and lead to phytotoxic effects, and the phytotoxicity is mainly caused by the release of the biologically active metabolite M2. This knowledge is valuable for designing crop rotation practices so that crop injury and yield losses due to carry-over herbicide phytotoxicity may be avoided.
采用¹⁴C标记示踪和生物测定技术，在三种不同土壤中研究了新型乙酰乳酸合成酶（ALS）潜在抑制剂除草剂ZJ0273的土壤结合残留（BR）对水稻（Oryza sativa L.）和玉米（Zea mays L.）的植物有效性及植物毒性。这三种土壤分别是潮滩黄壤土（S(1)）、红黏土（S(2)）和滨海盐土（S(3)）。当土壤中添加0.6、1.2和1.8 nmol g⁻¹的BR时，处理后14天内水稻幼苗出现剂量依赖性显著抑制，但相同处理下玉米幼苗未出现显著抑制。连续萃取后土壤提取物的放射性分析表明，种植后ZJ0273的¹⁴C标记残留从添加的土壤BR中释放出来。例如，添加1.8 nmol g⁻¹时，种植水稻幼苗的S(1)、S(2)和S(3)中，分别约有68.3%、57.0%和61.1%的添加BR被释放，而种植玉米幼苗的相应土壤中有38.9%、32.7%和32.6%的BR可被吸收。释放的化合物鉴定为ZJ0273及其降解产物M1和M2，其中M2是主要成分。对水稻的生物测定表明，ZJ0273、M1和M2的50%抑制浓度（IC₅₀）分别为33.16、1.93和0.49 μM。因此，施用ZJ0273后形成的BR在水稻种植期间可能被植物吸收并导致植物毒性效应，且植物毒性主要由生物活性代谢物M2的释放引起。这些知识对于设计作物轮作措施很有价值，从而可以避免因残留除草剂植物毒性导致的作物损伤和产量损失。
