Meta-analysis of the role of entomopathogenic and unspecialized fungal endophytes as plant bodyguards

Alan Gange, Julia Koricheva, Amanda Currie, Lara Jaber, Stefan Vidal

Research output: Contribution to journalArticlepeer-review

Abstract

Herbaceous plants harbour species-rich communities of asymptomatic endophytic fungi. Although some of these endophytes are entomopathogenic, many are not, and remarkably little is known about how the presence of these fungi in plant tissues affects phytophagous insects. Here we show through a meta-analysis that both entomopathogenic and nonentomopathogenic endophytes have a negative effect on insect herbivores. Growth and performance of polyphagous and sucking insects are reduced by nonentomopathogenic endophytes, but monophages are unaffected, likely because the latter are better adapted to secondary metabolites produced or induced by the fungi. Furthermore, studies using excised leaves report weaker effects than those with intact plants, likely caused by chemical changes being masked by leaf excision. Most surprisingly, endophyte infection of seeds produces the greatest effect on insect herbivores in subsequent mature plants, even though the usual mode of fungal transmission is infection of leaves by airborne spores. We conclude that these ubiquitous hidden fungi may be important bodyguards of plants. However, in order to fully understand their roles in plant protection, we must be aware that minor differences in experimental design can lead to contradictory results.
Original languageEnglish
Pages (from-to)2002-2010
Number of pages9
JournalNew Phytologist
Volume223
Issue number4
Early online date19 Apr 2019
DOIs
Publication statusPublished - Sept 2019

Keywords

  • Entomopathogen
  • systemic growth
  • seeds
  • insect herbivore
  • inoculation
  • effect size
  • defence

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