11
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Metarhizium robertsii produces indole-3-acetic acid, which promotes root growth in Arabidopsis and enhances virulence to insects.

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          The plant root colonizing insect-pathogenic fungus Metarhizium robertsii has been shown to boost plant growth, but little is known about the responsible mechanisms. Here we show that M. robertsii promotes lateral root growth and root hair development of Arabidopsis seedlings in part through an auxin [indole-3-acetic acid (IAA)]-dependent mechanism. M. robertsii, or its auxin-containing culture filtrate promoted root proliferation, activated IAA-regulated gene expression and rescued the root hair defect of the IAA-deficient rhd6 Arabidopsis mutant. Substrate feeding assays suggest that M. robertsii possesses tryptamine (TAM) and indole-3-acetamide tryptophan (Trp)-dependent auxin biosynthetic pathways. Deletion of Mrtdc impaired M. robertsii IAA production by blocking conversion of Trp to TAM but the reduction was not sufficient to affect plant growth enhancement. We also show that M. robertsii secretes IAA on insect cuticle. ∆Mrtdc produced fewer infection structures and was less virulent to insects than the wild-type, whereas M. robertsii spores harvested from culture media containing IAA were more virulent. Furthermore, exogenous application of IAA increased appressorial formation and virulence. Together, these results suggest that auxins play an important role in the ability of M. robertsii to promote plant growth, and the endogenous pathways for IAA production may also be involved in regulating entomopathogenicity. Auxins were also produced by other Metarhizium species and the endophytic insect pathogen Beauveria bassiana suggesting that interplay between plant- and fungal-derived auxins has important implications for plant-microbe-insect interactions.

          Related collections

          Author and article information

          Journal
          Microbiology (Reading, Engl.)
          Microbiology (Reading, England)
          Microbiology Society
          1465-2080
          1350-0872
          Jul 2017
          : 163
          : 7
          Affiliations
          [1 ] 1​College of Chemistry and Life Sciences, Guizhou Education University, Guiyang, Guizhou 550018, PR China.
          [2 ] 2​Department of Entomology, University of Maryland, College Park, MD 20742, USA.
          [3 ] 3​Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, PR China.
          Article
          10.1099/mic.0.000494
          28708056
          5585cc8f-ef00-450b-8c13-456c6f2bdecb
          History

          Comments

          Comment on this article