手性除草剂2甲4氯丙酸对映体在拟南芥中吸收转运及亚细胞分布的差异研究  

Uptake, Translocation and Subcellular Distribution of Mecoprop Enantiomers in Arabidopsis thaliana

作　　者：常江海 郭维[1] 郑姚颖 张素芬[1] 叶庆富[1] CHANG Jianghai;GUO Wei;ZHENG Yaoying;ZHANG Sufen;YE Qingfu(Institute of Nuclear-Agricultural Science,Zhejiang University/Key Laboratory of Ministry of Agriculture,Nuclear Agricultural Science,Hangzhou,Zhejiang 310029)

机构地区：[1]浙江大学原子核农业科学研究所/农业部核农学重点实验室,浙江杭州310029

出　　处：《核农学报》2021年第3期681-687,共7页Journal of Nuclear Agricultural Sciences

基　　金：国家基金面上项目(11675142);国家重点研发计划子课题(2016YFD0200201)。

摘　　要：为探明不同手性构型的2甲4氯丙酸(mecoprop,MCPP)在双子叶植物中的吸收、代谢等差异,以手性^(14)C-MCPP对映体为示踪剂,野生哥伦比亚型拟南芥为受试植物,研究实验室条件下不同手性构型的MCPP在拟南芥中的吸收转运与亚细胞分布特征。结果表明,拟南芥对^(14)C-MCPP 2种对映体的吸收效率分别为90.45%(^(14)C-R-MCPP)和85.75%(^(14)C-S-MCPP),二者差异显著。施药后,2种构型的^(14)C-MCPP均易向下运转,其中^(14)C-R-MCPP在拟南芥植株中的转运过程更持久,转运到植株其他部位的比率相对更高。2种构型^(14)C-MCPP在标记下位达到平衡时,^(14)C-R-MCPP的分布比率为^(14)C-S-MCPP的2.5倍。亚细胞分布方面,在拟南芥标记叶位细胞中各组分的分布比率均为胞浆>细胞壁>细胞器,在施药后144 h,^(14)C-S-MCPP在细胞壁的分布比率较^(14)C-R-MCPP高,分别为39.60%和28.74%,表明拟南芥叶组织细胞壁对^(14)C-S-MCPP具有更强的固定能力;而在细胞器中,^(14)C-R-MCPP的分布比率(10.55%)较^(14)C-S-MCPP(4.11%)高,表明^(14)C-R-MCPP相较于^(14)C-S-MCPP更易富集于叶组织细胞的细胞器中,在同施药浓度下与靶标蛋白的接触频率更高。综上可知,手性激素型除草剂MCPP在双子叶植物模式植物拟南芥中的运转和分布存在显著的对映体选择性差异,映证了R-MCPP从吸收、转运、亚细胞分布的层面而言相较于其对映体S-MCPP具有更强的除草活性。Mecoprop is a chiral auxin herbicide possessing one chiral center and two enantiomers and R-MCPP exhibits more significant herbicidal activity than S-MCPP. In order to Fig out the differences of absorption and metabolism of MCPP enantiomers in dicotyledons, the experiment an absorption, translocation and subcellular distribution of ^(14)C-MCPP enantiomers in Arabidopsis thaliana had been carried out under laboratory conditions with ^(14)C-MCPP enantiomers as tracer agent and Arabidopsis thaliana as plant material. The result showed that the plant took up the two enantiomers differently, with the absorption ratio of 85.75%(S-MCPP) and 90.45%(R-MCPP). As for translocation, R-MCPP had an increased translocation capacity with longer translocation time before equilibrium state and higher translocation ratio. Once reaching the balance, the translocation ratio of R-MCPP was 1.5 times greater than that of S-MCPP. Subcellular distribution test indicated that more of two MCPP enantiomers existed in the cytoplasm, followed by in cytoderm and organelle. The distribution ratio of S-MCPP(39.60%) in cytoderm was higher than that of R-MCPP(28.74%), indicating higher fixation of S-MCPP in cytoderm. Whereas the R-MCPP in organelle was 10.55% higher than 4.11% for S-MCPP, indicating that some herbicidal receptors were easier to be exposed to R-MCPP. According to the above results, the research, to a certain extent, elucidated the significant enantioselectivity of chiral MCPP on herbicidal activity in model dicotyledon Arabidopsis thaliana.

关 键 词：2甲4氯丙酸 拟南芥 吸收 转运 亚细胞分布 

分 类 号：S482.4[农业科学—农药学]