Comparative analysis of protein transport in the N. benthamiana vasculature reveals different destinations

Plant Signal Behav. 2011 Nov;6(11):1793-808. doi: 10.4161/psb.6.11.17896. Epub 2011 Nov 1.

Abstract

We investigated the vascular transport of exogenously applied proteins and compared their delivery to various aerial parts of the plant with carboxy fluorescein dye. Alexafluor tagged bovine serum albumin (Alexa-BSA) moves at a low level to upper parts of the plant and unloads to the apoplast. Alexafluor tagged Histone H1 (Alexa-Histone) moves rapidly throughout the plant 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 with barely any residual fluorescence left inside the leaf veins. Fluorescein tagged hepatitis C virus core protein (fluorescein-HCV) moves more rapidly than BSA 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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Fluorescence
  • Fluorescent Dyes / metabolism
  • Magnetic Resonance Imaging
  • Nicotiana / metabolism*
  • Phloem / metabolism*
  • Plant Leaves / metabolism*
  • Plant Roots / metabolism
  • Protein Transport
  • Serum Albumin, Bovine / metabolism*

Substances

  • Fluorescent Dyes
  • Serum Albumin, Bovine