title: Phloem mobility and translocation of fluorescent conjugate containing glucose and NBD in castor bean (Ricinus communis).
abstract: Phloem mobility is an important factor for long-distance transport of systemic pesticides in plants. Our previous study revealed that a fluorescent glucose-insecticide conjugate, N-{3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-iodo-1H-pyrazol-5-yl}-N-{[1-(β-D-glucopyranosyl)-1H-1,2,3-triazole-4-yl]methyl}-N-{[1-((N-(7-nitrobenz-2-oxa-1,3-diazole-4-amine))-propyl)-1H-1,2,3-triazole-4-yl]methyl}amine (IPGN), can be transported in tobacco cells. Several studies have also indicated that glucose moieties can guide the conjugates into plant cells. In this study, we investigated the phloem mobility of IPGN within castor bean seedlings. Cotyledon uptake experiment results show that IPGN could enter the phloem of the mid-veins of cotyledons. The results of further quantitative analysis show that IPGN was present in small amounts in the phloem sap despite the inconsistencies of physicochemical properties with diffusion through the plasma membrane. Its concentration in the phloem sap (about 370nM at 5h) was much lower than that in the incubation medium (100μM), which suggests that IPGN exhibited weak phloem mobility. After the leaves of Ricinus plantlets were treated with IPGN, green fluorescence could be observed in the phloem of the petioles, bud apical nodes, bud mid-veins, and mid-veins of the untreated leaves. The localization of the fluorescent conjugate at various levels of Ricinus plantlets indicates that it was translocated at a distance to sink organs via sieve tubes. The results proved that introducing a glucose group is a feasible approach to modify non-phloem-mobile pesticides and produce phloem-mobile pesticides.
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangzhou 510642, Guangdong, China; Key Laboratory of Natural Pesticide and Chemical Biology of the Ministry of Education, South China Agricultural University, Guangzhou 510642, Guangdong, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Lei
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangzhou 510642, Guangdong, China; Key Laboratory of Natural Pesticide and Chemical Biology of the Ministry of Education, South China Agricultural University, Guangzhou 510642, Guangdong, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangzhou 510642, Guangdong, China; Key Laboratory of Natural Pesticide and Chemical Biology of the Ministry of Education, South China Agricultural University, Guangzhou 510642, Guangdong, China.
authors.forename: Genlin
authors.initials: G
authors.lastname: Mao
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangzhou 510642, Guangdong, China; Key Laboratory of Natural Pesticide and Chemical Biology of the Ministry of Education, South China Agricultural University, Guangzhou 510642, Guangdong, China.
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Wen
authors.affiliation: State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangzhou 510642, Guangdong, China; Key Laboratory of Natural Pesticide and Chemical Biology of the Ministry of Education, South China Agricultural University, Guangzhou 510642, Guangdong, China. Electronic address: hhxu@scau.edu.cn.
authors.forename: Hanhong
authors.initials: H
authors.lastname: Xu
mesh_terms: D002851:Chromatography, High Pressure Liquid; D018548:Cotyledon / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry* / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D010069:Oxadiazoles / Q000737:chemistry* / Q000494:pharmacology; D052585:Phloem / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D012278:Ricinus / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D013997:Time Factors; D014230:Triazoles / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D005456:Fluorescent Dyes; D005960:Glucosides; D010069:Oxadiazoles; D014230:Triazoles; D005947:Glucose
keywords: Fluorescence microscopy; Fluorescent glucose-conjugate; Phloem mobility; Translocation; Visualization