Diversity and phylogenetic analysis of endosymbiotic bacteria of the date palm root borer Oryctes agamemnon (Coleoptera: Scarabaeidae)

Abstract

BackgroundThe date palm root borer Oryctes agamemnon (Coleoptera: Scarabaeidae) is one of the major pests of palms. In Saudi Arabia, both larvae and adults of Oryctes are particularly troublesome, especially during the establishment of young date palm orchards. Endosymbiotic bacteria are known to have a key role in food digestion and insecticide resistance mechanisms, and therefore are essential to their host insect. Identification of these bacteria in their insect host can lead to development of new insect pest control strategies.ResultsMetagenomic DNA from larval midgut of the date palm root borer, O. agamemnon, was analyzed for endosymbiotic bacterial communities using denatured gradient gel electrophoresis (DGGE) utilizing 16S rRNA genes. The DGGE fingerprints with metagenomic DNA showed predominance of eleven major operational taxonomic units (OTUs) identified as members of Photobacterium, Vibrio, Allomonas, Shewanella, Cellulomonas, and Citrobacter, as well as uncultured bacteria, including some uncultured Vibrio members. DGGE profiles also showed shifts in the dominant bacterial populations of the original soil compared with those that existed in the larval midguts. The endosymbiotic bacterial community was dominated by members of the family Vibrionaceae (54.5%), followed by uncultured bacteria (18.2%), Enterobacteriaceae (9.1%), Shewanellaceae (9.1%), and Cellulomonadaceae (9.1%). Phylogenetic studies confirmed the affiliation of the dominant OTUs into specified families revealed by clustering of each phylotype to its corresponding clade. Relative frequency of each phylotype in larval midguts revealed predominance of Vibrio furnisii and Vibrio navarrensis, followed by uncultured bacterial spp., then Cellulomonas hominis, Shewanella algae, and Citrobacter freundii.ConclusionAnalysis of metagenomic DNA for endosymbiotic bacterial communities from the midgut of Oryctes larvae showed strong selection of specific bacterial populations that may have a key role in digestion, as well as other benefits to the larvae of O. agamemnon. Determination of the distinct endosymbiotic community structure and its possible biological functions within the insect could provide us with basic information for future pest control research.

Impact of nanoparticles on transcriptional regulation of catabolic genes of petroleum hydrocarbon‐degrading bacteria in contaminated soil microcosms

“…One specific set of primer pairs ( 23cat) was tested in this study to evaluate the expression level of catechol 2,3 dioxygenase as an indicator for biodegradation potential in polluted soils amended with NPs using RT‐qPCR. In general, it was found by DGGE analysis that polluted soils had a bacterial community pattern that is different from that detected in similar but unpolluted soils . Contamination has led to a unique pattern in microbial populations with those having biodegradation potentials for corresponding contaminant.…”

The mechanism of plant gall induction by insects: revealing clues, facts, and consequences in a cross-kingdom complex interaction

“…Symbiotic relationships between gallinducing insects and microorganisms have been hypothesized to be involved in plant gall development (Hansen & Moran, 2014;Tooker and Helms, 2014). Several studies have demonstrated the presence of a great number of endosymbiotic bacteria in different insect groups (Degnan, Lazarus, & Wernegreen, 2005;Kikuchi, Meng & Fukatsu, 2005;Delmotte, Rispe, Schaber, Silva, & Moya, 2006;Fukatsu et al, 2007;Jaenike, Polak, Fiskin, Helou, & Minhas, 2007;Goto, Anbutsu, & Fukutsa, 2006;Xi, Gavotte, Xie, & Dobson, 2008;Toft, Williams, & Fares, 2009;Gutzwiller, Dedeine, Káiser, & Giron, 2015;Krawczyk, Szymańczyk, & Obrępalska-Stęplowska, 2015;El-Sayed & Ibrahim, 2015;Campbell et al, 2015), as well as bacteriocytes (Nikoh & Nakabachi, 2009;Braendle et al, 2009). Some of these symbiont microorganisms are mutualistic and contribute to the viability of their hosts, while others are parasites, which tend to affect their corresponding hosts in a negative way.…”

“…Insect-associated microorganisms could be important mediators of interactions between insects and plants (Sugio, Dubreuil, Giron, & Simon, 2015;Hammer & Bowers, 2015, Wielkopolan & Obrępalska-Stęplowska, 2016. Some researchers have reported that simultaneous infection with different species of endosymbionts in the same host organism is a common phenomenon in several insect groups (Thao et al, 2000;Thao, Gullan, & Baumann, 2002;Russell et al, 2003;Ishii, Matsuura, Kakizawa, Nikoh, & Fukatsu, 2013;Krawczyk et al, 2015;El-Sayed et al, 2015;Ghosh, Bouvaine, & Maruthi, 2015;Brentassi et al, 2017). Different tissues in the body of the same host constitute different microenvironments for endosymbiont organisms.…”

Assessment of the virulence and proteolytic activity of three native entomopathogenic fungi against the larvae of Oryctes agamemnon (Burmeister) (Coleoptera: Scarabaeidae)

“…At present, the management of O. agamemnon in date palm orchard is either non-existent (by small scale farmers) or relies on the application of insecticides in large areas, such as carbofuran and certain biocontrol agents (Zelazny et al 1992). Several studies were carried out to control Oryctes either through using botanicals (Ibrahim and Alahmadi 2015) or determination of distinct endosymbiotic community structure and its possible biological functions within the insect to conclude basic information for future pest control (El-Sayed and Ibrahim 2015). Recently, certain entomopathogenic fungi such as Beauveria bassiana, Metarhizium anisopliae, and Lecanicillium lecanii have been applied against Oryctes and resulted in satisfactory mortalities to both adults and larvae of the pest (Ibrahim 2017).…”