Abstract

The plant hormones ethylene, jasmonic acid and salicylic acid have interconnecting roles during the response of plant tissues to mutualistic and pathogenic symbionts.We used morphological studies of transgenic- or hormone-treated Populus roots as well as whole-genome oligoarrays to examine how these hormones affect root colonization by the mutualistic ectomycorrhizal fungus Laccaria bicolor S238N.We found that genes regulated by ethylene, jasmonic acid and salicylic acid were regulated in the late stages of the interaction between L. bicolor and poplar. Both ethylene and jasmonic acid treatments were found to impede fungal colonization of roots, and this effect was correlated to an increase in the expression of certain transcription factors (e.g. ETHYLENE RESPONSE FACTOR1) and a decrease in the expression of genes associated with microbial perception and cell wall modification. Further, we found that ethylene and jasmonic acid showed extensive transcriptional cross-talk, cross-talk that was opposed by salicylic acid signaling.We conclude that ethylene and jasmonic acid pathways are induced late in the colonization of root tissues in order to limit fungal growth within roots. This induction is probably an adaptive response by the plant such that its growth and vigor are not compromised by the fungus.

Keywords

ethylene response factor; hormone cross-talk; mycorrhizal fungi; plant defense; plant hormone; salicylic acid

Published in

New Phytologist
2014, Volume: 202, number: 1, pages: 270-286
Publisher: WILEY-BLACKWELL

SLU Authors

• Sundberg, Björn

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

Associated SLU-program

SLU Plant Protection Network


UKÄ Subject classification

Microbiology
Botany


Publication identifier

DOI: https://doi.org/10.1111/nph.12655

Permanent link to this page (URI)

https://res.slu.se/id/publ/67603