Title: | Root Colonization by Fungal Entomopathogen Systemically Primes Belowground Plant Defense against Cabbage Root Fly |
Author(s): | Posada-Vergara C; Lohaus K; Alhussein M; Vidal S; Rostas M; |
Address: | "Agricultural Entomology, Department of Crop Sciences, University of Gottingen, Grisebachstr 6, 37077 Gottingen, Germany. Molecular Phytopathology and Mycotoxin Research, Department of Crop Sciences, University of Gottingen, Grisebachstr 6, 37077 Gottingen, Germany" |
ISSN/ISBN: | 2309-608X (Electronic) 2309-608X (Linking) |
Abstract: | "Entomopathogenic fungi infect insects via spores but also live inside plant tissues as endophytes. Frequently, colonization by entomopathogens provides plants with increased resistance against insects, but the mechanisms are little understood. This study investigated direct, local, and systemic root-mediated interactions between isolates of the fungus Metarhizium brunneum and larvae of the cabbage root fly (CRF) Delia radicum attacking Brassica napus plants. All fungal isolates infected CRF when conidia were present in the soil, leading to 43-93% mortality. Locally, root-associated M. brunneum isolates reduced herbivore damage by 10-20% and in three out of five isolates caused significant insect mortality due to plant-mediated and/or direct effects. A split-root experiment with isolate Gd12 also demonstrated systemic plant resistance with significantly reduced root collar damage by CRF. LC-MS analyses showed that fungal root colonization did not induce changes in phytohormones, while herbivory increased jasmonic acid (JA) and glucosinolate concentrations. Proteinase inhibitor gene expression was also increased. Fungal colonization, however, primed herbivore-induced JA and the expression of the JA-responsive plant defensin 1.2 (PDF1.2) gene. We conclude that root-associated M. brunneum benefits plant health through multiple mechanisms, such as the direct infection of insects, as well as the local and systemic priming of the JA pathway" |
Keywords: | Brassica napus Delia radicum Metarhizium brunneum endophytic entomopathogenic fungi glucosinolates jasmonic acid plant-fungal-insect interactions split-root; |
Notes: | "PubMed-not-MEDLINEPosada-Vergara, Catalina Lohaus, Katharina Alhussein, Mohammad Vidal, Stefan Rostas, Michael eng Convocatoria No. 783 de 2017/Colciencias/ Switzerland 2022/09/23 J Fungi (Basel). 2022 Sep 16; 8(9):969. doi: 10.3390/jof8090969" |