Evidence suggesting interactions between immunodominant membrane protein Imp of Flavescence dorée phytoplasma and protein extracts from distantly related insect species

Abstract

Aims In this study, binding between the immunodominant membrane protein Imp of the 16SrV‐D phytoplasma associated with Flavescence dorée disease (FD‐Dp) and insect proteins of vectors and non‐vectors of FD‐Dp was tested. Methods and Results Six Auchenorrhyncha species, from distantly related groups were selected: Scaphoideus titanus, Euscelidius variegatus, Macrosteles quadripunctulatus, Zyginidia pullula (Cicadomorpha), Ricania speculum and Metcalfa pruinosa (Fulgoromorpha). The vector status of each species was retrieved from the literature or determined by transmission trials in this study. A His‐tagged partial Imp protein and a rabbit polyclonal antibody were synthesized and used for Western and Far‐Western dot Blot (FWdB) experiments. Total native and membrane proteins (MP) were extracted from entire bodies and organs (gut and salivary glands) of each insect species. FWdB showed decreasing interaction intensities of Imp fusion protein with total proteins from entire bodies of S. titanus, E. variegatus (competent vectors) and M. quadripunctulatus (non‐vector), while no interaction signal was detected with the other three species (non‐vectors). A strong signal detected upon interaction of FD‐D Imp and MP from guts of closely related insects supports the role of this organ as the first barrier to ensure successful transmission. Conclusions Our results showed that specific Imp binding, correlated with vector status, is involved in interactions between FD‐Dp and insect proteins. Significance and Impact of the Study Integrating knowledge on host–pathogen protein–protein interactions and on insect phylogeny would help to identify the actual range of vectors of phytoplasma strains of economic importance.

Genetic variation, phylogenetic relationship and spatial distribution of ‘Candidatus Phytoplasma ulmi’ strains in Germany

“…Whether or not the ‘ Ca. P. ulmi’ membrane protein has an important function in host–pathogen recognition, as studies with other phytoplasmas suggest 28 , 32 , 34 , remains to be demonstrated, but in a recent study the interaction of the FD-D IMP with gut membrane proteins of vector species was proven 35 . That immunodominant phytoplasma membrane proteins seem to play a generally important role in the attachment to host cell membranes has been also demonstrated for AMP, a major membrane protein of aster yellows group phytoplasmas 36 .…”

Silencing of ATP synthase β induces female sterility in a leafhopper phytoplasma vector

“…Phytoplasmas are obligate parasites and display a dual life cycle, infecting phloem of the host plant as well as the insect vector body. Several lines of evidence indicate that interactions between phytoplasmas and vector host cells are tightly regulated and determine transmission ability (Arricau-Bouvery et al 2018;Galetto et al 2011;Malembic-Maher et al 2020;Rashidi et al 2015;Suzuki et al 2006;Trivellone et al 2019). In particular, previous studies demonstrated that ATP synthase β subunit of E. variegatus is expressed in the mitochondria as well as on the plasma membrane and interacts in vitro with the antigenic membrane protein of CY phytoplasma (Galetto et al 2011).…”

Biological and molecular evidence for the transmission of aster yellows phytoplasma to French marigold (Tagetes patula) by the flatid planthopper Metcalfa pruinosa

“…Chardonnay). However, in more recent experiments, M. pruinosa has failed to transmit flavescence dorée phytoplasma and clover phyllody to grapevine, broadbean ( Vicia faba L.) and nettle ( Urtica dioica L.) (Bressan et al, ; Clair et al, ; Trivellone et al, ). Such inconsistent findings may be related to the specific relationship between the phytoplasma and insect vector (Lee et al, ; Weintraub & Beanland, ).…”

“…A preliminary study suggested that M. pruinosa adults might transmit clover phyllody phytoplasma to grapevine ( Vitis vinifera L.), however, the results were inconclusive because of the small sample size (Guadagnini et al, ). So far, its ability to transfer phytoplasma has not been confirmed (Bressan, Clair, Sémétey, & Boudon‐Padieu, ; Clair, Larrue, & Boudon‐Padieu, ; Trivellone et al, ). Therefore, further transmission experiments are necessary to establish the potential contribution of M. pruinosa to the spread of phytoplasma diseases, which is difficult, considering how broad the spectrum of associated host plants and phytoplasmas is and how complex the phytoplasma–plant–vector interaction is (Bosco, Minucci, Boccardo, & Conti, ; Galetto, Marzachì, Demichelis, & Bosco, ; Murral et al, ).…”