Long-distance movement factor: a transport function of the potyvirus helper component proteinase. Academic Article uri icon


  • Transport of viruses from cell to cell in plants typically involves one or more viral proteins that supply dedicated movement functions. Transport from leaf to leaf through phloem, or long-distance transport, is a poorly understood process with requirements differing from those of cell-to-cell movement. Through genetic analysis of tobacco etch virus (TEV; potyvirus group), a novel long-distance movement factor was identified that facilitates vascular-associated movement in tobacco. A mutation in the central region of the helper component proteinase (HC-Pro), a TEV-encoded protein with previously described activities in aphid-mediated transmission and polyprotein processing, inactivated long-distance movement. This mutant virus exhibited only minor defects in genome amplification and cell-to-cell movement functions. In situ histochemical analysis revealed that the mutant was capable of infecting mesophyll, bundle sheath, and phloem cells within inoculated leaves, suggesting that the long-distance movement block was associated with entry into or exit from sieve elements. The long-distance movement defect was specifically complemented by HC-Pro supplied in trans by a transgenic host. The data indicate that HC-Pro functions in one or more steps unique to long-distance transport.

published proceedings

  • Plant Cell

altmetric score

  • 3

author list (cited authors)

  • Cronin, S., Verchot, J., Haldeman-Cahill, R., Schaad, M. C., & Carrington, J. C.

citation count

  • 133

complete list of authors

  • Cronin, S||Verchot, J||Haldeman-Cahill, R||Schaad, MC||Carrington, JC

publication date

  • May 1995