Functional foregut anatomy of the blue–green sharpshooter illustrated using a 3D model

Authors: WHITE, DANIEL - University Of California; Backus, Elaine; MARCUS, IAN - Drexel University; WALKER, SHARON - Drexel University; ROPER, M. CAROLINE - University Of California

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2020
Publication Date: 3/22/2021
Citation: White, D., Backus, E.A., Marcus, I.M., Walker, S.L., Roper, M. 2021. Functional foregut anatomy of the blue–green sharpshooter illustrated using a 3D model. Scientific Reports. 11. Article 6536. https://doi.org/10.1038/s41598-021-85954-4.
DOI: https://doi.org/10.1038/s41598-021-85954-4

Interpretive Summary: Xylella fastidiosa is an invasive plant-infecting bacterium that causes economically significant agricultural losses worldwide from diseases such as olive quick decline syndrome in Europe, citrus variegated chlorosis in South America, and Pierce’s disease of grape in North America. Sharpshooter leafhoppers are important carriers of X. fastidiosa. Bacteria-containing fluids are taken up during feeding by sharpshooters on infected plants, and later injected into healthy plants. Such transmission is linked to fluid movements in and out of the carrier’s functional foregut and colonization by bacterial cells. One key X. fastidiosa carrier is the blue-green sharpshooter, Graphocephala atropunctata. In this study, a three-dimensional model of the functional foregut of blue-green sharpshooter was developed from microscopy images. The model is used to illustrate anatomy of the functional foregut, as well as existing and newly defined anatomical terms that will aid in future studies of fluid movements in the sharpshooter functional foregut. The three-dimensional (3D) illustrations and supplementary interactive 3D figures provide resources for collaborating researchers from many disciplines, who may be unfamiliar with insect anatomy. The model can also be used in future computer simulations of fluid dynamics, to better understand transmission of X. fastidiosa. Improved understanding of the transmission processes from this research will lead to new targets for breeding crops that will be resistant to X. fastidiosa.

Technical Abstract: Sharpshooter leafhoppers (Hemiptera: Cicadellidae: Cicadellinae) are important vectors of the plant pathogenic bacterium Xylella fastidiosa Wells et al. (Xanthomonadales: Xanthomonadaceae). This pathogen causes economically significant diseases in olive, citrus, and grapes on multiple continents. Bacterial acquisition and inoculation mechanisms are linked to X. fastidiosa biofilm formation and fluid dynamics in the functional foregut of sharpshooters, which together result in egestion (expulsion) of fluids likely carrying bacteria. One key X. fastidiosa vector is the blue-green sharpshooter, Graphocephala atropunctata Signoret. Herein, a 3D model of the blue-green sharpshooter functional foregut is derived from a meta-analysis of published microscopy images. The model is used to illustrate preexisting and newly defined anatomical terminology that is relevant for investigating fluid dynamics in the functional foregut of sharpshooters. The 3D illustrations herein and supplementary interactive 3D figures are suitable resources for multidisciplinary researchers who may be unfamiliar with insect anatomy. The 3D model can also be used in future fluid dynamic simulations to better understand acquisition, retention, and inoculation of X. fastidiosa. Improved understanding of these processes could lead to new targets for breeding crops that will be resistant to X. fastidiosa.