Oxalate contributes to the resistance of Gaillardia grandiflora and Lupinus sericeus to a phytotoxin produced by Centaurea maculosa

Tiffany L. Weir, Harsh Pal Bais, Valerie J. Stull, Ragan M. Callaway, Giles C. Thelen, Wendy M. Ridenour, Suresh Bhamidi, Frank R. Stermitz, Jorge M. Vivanco

Research output: Contribution to journalArticlepeer-review

Abstract

Centaurea maculosa Lam. is a noxious weed in western North America that produces a phytotoxin, (±)-catechin, which is thought to contribute to its invasiveness. Areas invaded by C. maculosa often result in monocultures of the weed, however; in some areas, North American natives stand their ground against C. maculosa and show varying degrees of resistance to its phytotoxin. Two of these resistant native species, Lupinus sericeus Pursh and Gaillardia grandiflora Van Houtte, were found to secrete increased amounts of oxalate in response to catechin exposure. Mechanistically, we found that oxalate works exogenously by blocking generation of reactive oxygen species in susceptible plants and reducing oxidative damage generated in response to catechin. Furthermore, field experiments show that L. sericeus indirectly facilitates native grasses in grasslands invaded by C. maculosa, and this facilitation can be correlated with the presence of oxalate in soil. Addition of exogenous oxalate to native grasses and Arabidopsis thaliana (L.) Heynh grown in vitro alleviated the phytotoxic effects of catechin, supporting the field experiments and suggesting that root-secreted oxalate may also act as a chemical facilitator for plant species that do not secrete the compound.

Original languageEnglish
Pages (from-to)785-795
Number of pages11
JournalPlanta
Volume223
Issue number4
DOIs
StatePublished - Mar 2006

Keywords

  • Allelopathy
  • Catechin
  • Centaurea
  • Oxalate
  • Resistance

Fingerprint

Dive into the research topics of 'Oxalate contributes to the resistance of Gaillardia grandiflora and Lupinus sericeus to a phytotoxin produced by Centaurea maculosa'. Together they form a unique fingerprint.

Cite this