Study of Vascular Transport of Plant Exogenous Proteins in Nicotiana Benthamiana and Brassica Oleracea Using Fluorescence and Megnetic Resonance Imaging Technology

Abstract

Use fluorescence and MRI imaging technology to characterize long distance transport of fluorescence conjugated proteins and virus protein in Nicotiana benthamiana and Brassica oleracea. The investigation of vascular transport of exogenously applied proteins will lay the foundation of studying the movement of virion nanoparticles as biomedicine in plants and help to study potential uptake of foodborne contaminants by plants. Research on the vascular transport of exogenously applied proteins and compared their delivery to various parts of the Nicotiana benthamiana and Brassica oleracea plants with carboxy fluorescein dye reveals Alexa fluor tagged bovine serum albumin (Alexa-BSA) follows a low level of movement to upper parts of the plant and unloads to the apoplast. Alexa fluor tagged Histone H1 (Alexa-Histone) moves relatively rapid and is retained in the phloem and phloem parenchyma. Both Alexa-Histone and -BSA were exported from leaf veins class II and III but they unloaded completely into the leaf lamina as fluorescent epidermal and mesophyll cells in N. benthamiana and as fluorescent stomata in B. oleracea. There is barely any residual fluorescence left inside the leaf veins in N. benthamiana. Fluorescein tagged hepatitis C virus core protein (fluorescein-HCV) moves more rapidly than BSA in N. benthamiana but does not reach the level of Histone through the plant and was restricted to the leaf veins. Fluorescein-HCV failed to unload to the leaf lamina. These combined data suggest that there is not a single default pathway for the transfer of exogenous proteins through the plant. Specific protein properties appear to determine their destination and transport properties within the phloem. The factors of water content, application methods play different roles on protein transport in different plants.