Plant defensins and virally encoded fungal toxin KP4 inhibit plant root growth

Aron Allen, Anita K. Snyder, Mary Preuss, Erik E. Nielsen, Dilip M. Shah, Thomas Smith

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

Plant defensins are small, highly stable, cysteine-rich antimicrobial proteins that are thought to constitute an important component of plant defense against fungal pathogens. There are a number of such defensins expressed in various plant tissues with differing antifungal activity and spectrum. Relatively little is known about the modes of action and biological roles of these proteins. Our previous work on a virally encoded fungal toxin, KP4, from Ustilago maydis and subsequently with the plant defensin, MsDef1, from Medicago sativa demonstrated that some of these proteins specifically blocked calcium channels in both fungi and animals. The results presented here demonstrate that KP4 and three plant defensins, MsDef1, MtDef2, and RsAFP2, all inhibit root growth in germinating Arabidopsis seeds at low micromolar concentrations. We have previously demonstrated that a fusion protein composed of Rab GTPase (RabA4b) and enhanced yellow fluorescent protein (EYFP) is dependent upon calcium gradients for localization to the tips of the growing root hairs in Arabidopsis thaliana. Using this tip-localized fusion protein, we demonstrate that all four proteins rapidly depolarize the growing root hair and block growth in a reversible manner. This inhibitory activity on root and root hair is not directly correlated with the antifungal activity of these proteins and suggests that plants apparently express targets for these antifungal proteins. The data presented here suggest that plant defensins may have roles in regulating plant growth and development.

Original languageEnglish (US)
Pages (from-to)331-339
Number of pages9
JournalPlanta
Volume227
Issue number2
DOIs
StatePublished - Jan 2008
Externally publishedYes

Fingerprint

Defensins
Plant Roots
Mycotoxins
mycotoxins
root growth
root hairs
Growth
Proteins
proteins
Arabidopsis
antifungal proteins
antimicrobial proteins
Ustilago zeae
calcium channels
rab GTP-Binding Proteins
guanosinetriphosphatase
Ustilago
Plant Structures
Medicago sativa
Plant Proteins

Keywords

  • Plant defensin
  • Root
  • Root hair

ASJC Scopus subject areas

  • Plant Science

Cite this

Allen, A., Snyder, A. K., Preuss, M., Nielsen, E. E., Shah, D. M., & Smith, T. (2008). Plant defensins and virally encoded fungal toxin KP4 inhibit plant root growth. Planta, 227(2), 331-339. https://doi.org/10.1007/s00425-007-0620-1

Plant defensins and virally encoded fungal toxin KP4 inhibit plant root growth. / Allen, Aron; Snyder, Anita K.; Preuss, Mary; Nielsen, Erik E.; Shah, Dilip M.; Smith, Thomas.

In: Planta, Vol. 227, No. 2, 01.2008, p. 331-339.

Research output: Contribution to journalArticle

Allen, A, Snyder, AK, Preuss, M, Nielsen, EE, Shah, DM & Smith, T 2008, 'Plant defensins and virally encoded fungal toxin KP4 inhibit plant root growth', Planta, vol. 227, no. 2, pp. 331-339. https://doi.org/10.1007/s00425-007-0620-1
Allen, Aron ; Snyder, Anita K. ; Preuss, Mary ; Nielsen, Erik E. ; Shah, Dilip M. ; Smith, Thomas. / Plant defensins and virally encoded fungal toxin KP4 inhibit plant root growth. In: Planta. 2008 ; Vol. 227, No. 2. pp. 331-339.
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