Skipping the Insect Vector: Plant Stolon Transmission of the Phytopathogen ‘Ca. Phlomobacter fragariae’ from the Arsenophonus Clade of Insect Endosymbionts
Open Access
- 22 January 2021
- Vol. 12 (2), 93
- https://doi.org/10.3390/insects12020093
Abstract
The genus Arsenophonus represents one of the most widespread clades of insect endosymbionts, including reproductive manipulators and bacteriocyte-associated primary endosymbionts. Two strains belonging to the Arsenophonus clade have been identified as insect-vectored plant pathogens of strawberry and sugar beet. The bacteria accumulate in the phloem of infected plants, ultimately causing leaf yellows and necrosis. These symbionts therefore represent excellent model systems to investigate the evolutionary transition from a purely insect-associated endosymbiont towards an insect-vectored phytopathogen. Using quantitative PCR and transmission electron microscopy, we demonstrate that ‘Candidatus Phlomobacter fragariae’, bacterial symbiont of the planthopper Cixius wagneri and the causative agent of Strawberry Marginal Chlorosis disease, can be transmitted from an infected strawberry plant to multiple daughter plants through stolons. Stolons are horizontally growing stems enabling the nutrient provisioning of daughter plants during their early growth phase. Our results show that Phlomobacter was abundant in the phloem sieve elements of stolons and was efficiently transmitted to daughter plants, which rapidly developed disease symptoms. From an evolutionary perspective, Phlomobacter is, therefore, not only able to survive within the plant after transmission by the insect vector, but can even be transmitted to new plant generations, independently from its ancestral insect host.Keywords
Funding Information
- European Commission (792813)
This publication has 55 references indexed in Scilit:
- To B or Not to B: Comparative Genomics Suggests Arsenophonus as a Source of B Vitamins in WhitefliesFrontiers in Microbiology, 2018
- Reproductive Parasitism: Maternally Inherited Symbionts in a Biparental WorldCold Spring Harbor Perspectives in Biology, 2015
- Evolutionary origin of insect– Wolbachia nutritional mutualismProceedings of the National Academy of Sciences of the United States of America, 2014
- Wolbachia Variants Induce Differential Protection to Viruses in Drosophila melanogaster: A Phenotypic and Phylogenomic AnalysisPLoS Genetics, 2013
- Evolutionary replacement of obligate symbionts in an ancient and diverse insect lineageEnvironmental Microbiology, 2013
- Aphid genome expression reveals host–symbiont cooperation in the production of amino acidsProceedings of the National Academy of Sciences of the United States of America, 2011
- Adaptation via Symbiosis: Recent Spread of a Drosophila Defensive SymbiontScience, 2010
- Wolbachia: master manipulators of invertebrate biologyNature Reviews Microbiology, 2008
- Linking the bacterial community in pea aphids with host‐plant use and natural enemy resistanceEcological Entomology, 2004
- Facultative bacterial symbionts in aphids confer resistance to parasitic waspsProceedings of the National Academy of Sciences of the United States of America, 2003