title: Glyphosate inhibits the translocation of green fluorescent protein and sucrose from a transgenic tobacco host to Cuscuta campestris Yunk.
abstract: The parasitic plant Cuscuta campestris is dependent on its host for water, assimilates and amino acids. It can be controlled by the herbicide glyphosate, which inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS), resulting in shikimate accumulation. In this study, C. campestris was parasitic on transgenic tobacco plants expressing green fluorescent protein (GFP) in the phloem. Changes in [14C]sucrose and GFP accumulation in the parasite were used as indicators of the herbicide's effect on translocation between the host and parasite. Host plants were treated with glyphosate 22 days after sowing. Shikimate accumulation in the parasite 1 day after glyphosate treatment (DAGT) confirmed EPSPS inhibition in C. campestris. No damage was visible in the host plants for the first 3 DAGT, while during that same time, a significant reduction in [14C]sucrose and GFP accumulation was observed in the parasite. Thus, we propose that the parallel reduction in GFP and sucrose accumulation in C. campestris is a result of a glyphosate effect on the parasite's ability to withdraw assimilates from the host.
authors.affiliation: R.H. Smith Institute of Plant Sciences and Genetics in Agriculture, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, 76100, Rehovot, Israel.
authors.forename: Talia
authors.initials: T
authors.lastname: Nadler-Hassar
authors.forename: Alexander
authors.initials: A
authors.lastname: Goldshmidt
authors.forename: Baruch
authors.initials: B
authors.lastname: Rubin
authors.forename: Shmuel
authors.initials: S
authors.lastname: Wolf
mesh_terms: D034182:Cuscuta / Q000187:drug effects / Q000378:metabolism*; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D006540:Herbicides / Q000494:pharmacology; D018613:Microscopy, Confocal; D030821:Plants, Genetically Modified; D021381:Protein Transport; D011994:Recombinant Proteins / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism*; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D000097797:Glyphosate
chemical_list: D005998:Glycine; D049452:Green Fluorescent Proteins; D006540:Herbicides; D011994:Recombinant Proteins; D013395:Sucrose; D000097797:Glyphosate