Inactivation of the lipoxygenase ZmLOX3 increases susceptibility of maize to Aspergillus spp. Academic Article uri icon

abstract

  • Plant and fungal lipoxygenases (LOX) catalyze the oxidation of polyunsaturated fatty acids, creating fatty-acid hydroperoxides (oxylipins). Fungal oxylipins are required for normal fungal development and secondary metabolism, and plant host-derived oxylipins interfere with these processes in fungi, presumably by signal mimicry. The maize LOX gene ZmLOX3 has been implicated previously in seed-Aspergillus interactions, so we tested the interactions of a mutant maize line (lox3-4, in which ZmLOX3 is disrupted) with the mycotoxigenic seed-infecting fungi Aspergillus flavus and Aspergillus nidulans. The lox3-4 mutant was more susceptible than wild-type maize to both Aspergillus species. All strains of A. flavus and A. nidulans produced more conidia and aflatoxin (or the precursor sterigmatocystin) on lox3-4 kernels than on wild-type kernels, in vitro and under field conditions. Although oxylipins did not differ detectably between A. flavus-infected kernels of the lox3-4 and wild-type (WT) maize, oxylipin precursors (free fatty acids) and a downstream metabolite (jasmonic acid) accumulated to greater levels in lox3-4 than in WT kernels. The increased resistance of the lox3-4 mutant to other fungal pathogens (Fusarium, Colletotrichum, Cochliobolus, and Exserohilum spp.) is in sharp contrast to results described herein for Aspergillus spp., suggesting that outcomes of LOX-governed host-pathogen interactions are pathogen-specific.

published proceedings

  • Mol Plant Microbe Interact

altmetric score

  • 1

author list (cited authors)

  • Gao, X., Brodhagen, M., Isakeit, T., Brown, S. H., Gbel, C., Betran, J., ... Kolomiets, M. V.

citation count

  • 110

complete list of authors

  • Gao, Xiquan||Brodhagen, Marion||Isakeit, Tom||Brown, Sigal Horowitz||Göbel, Cornelia||Betran, Javier||Feussner, Ivo||Keller, Nancy P||Kolomiets, Michael V

publication date

  • February 2009