, Volume 224, Issue 4, pp 750–760

Evolution of proteinase inhibitor defenses in North American allopolyploid species of Nicotiana

  • Jianqiang Wu
  • Christian Hettenhausen
  • Ian T. Baldwin
Original Article

DOI: 10.1007/s00425-006-0256-6

Cite this article as:
Wu, J., Hettenhausen, C. & Baldwin, I.T. Planta (2006) 224: 750. doi:10.1007/s00425-006-0256-6


We studied the jasmonate (JA)-elicited trypsin-proteinase inhibitor (TPI) anti-herbivore defense system in North American Nicotiana to understand how complex polygenetic traits evolve after allopolyploidy speciation. N. quadrivalvis (Nq) and N. clevelandii (Nc) are allotetraploid descendant species of the ancestors of the diploid species N. attenuata (Na) and N. obtusifolia (No). From cDNA, intron and promoter sequence analyses, and Southern blotting, we deduced that only the maternally derived No TPI genes were retained in the tetraploid genomes (Nq, Nc), whereas the sequences of the paternal Na ancestor were deleted. The number of TPI repeats in different Nicotiana taxa was independent of phylogenetic associations. In Na, TPI activity and mRNA transcript accumulation as well as JA levels increased dramatically above wound-induced levels when the oral secretions (OS) from Manduca sexta larvae were introduced into wounds. This OS-mediated amplification of defense signaling and downstream response was also found in the tetraploid genomes but was absent from No; in No, OS treatment suppresses TPI mRNA accumulation and activity and does not increase JA accumulation. Hence, the tetraploids retained components of Na’s signaling system, but lost Na’s TPI genes and used No’s TPI genes to retain a functional TPI defense system, underscoring the genomic flexibility that enables complex polygenic traits to be retained in allopolyploid species.


NicotianaPlant–herbivore interactionPolygenic adaptationPolyploidyProteinase inhibitorSolanaceae



Analysis of variance


High-performance liquid chromatography coupled tandem mass spectrometry


Internal transcribed spacer




Nicotiana attenuata


N. clevelandii


N. obtusifolia


N. quadrivalvis


Oral secretions


Trypsin-proteinase inhibitor

Supplementary material

425_2006_256_MOESM1_ESM.pdf (196 kb)
Supplementary material

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Jianqiang Wu
    • 1
  • Christian Hettenhausen
    • 1
  • Ian T. Baldwin
    • 1
  1. 1.Department of Molecular EcologyMax-Planck-Institute for Chemical EcologyJenaGermany