Australian sugarcane soldier fly's salivary gland transcriptome in response to starvation and feeding on sugarcane crops

Abstract

The soldier fly is an endemic pest of sugarcane in Australia. Small numbers of larvae can cause significant damage to roots and reduce the crop yields. Little is known about the composition and function of the soldier fly salivary gland, its secretions, and their roles in insect-plant interactions. In this study, we performed transcriptome analysis of the salivary glands of starved and sugarcane root-fed soldier fly larvae. A total of 31 119 highly expressed assembled contigs were identified in the salivary glands and almost 50% of them showed high levels of similarity to known proteins in Nr databases. Of all the obtained contigs, only 9727 sequences contain an open reading frame of over 100 amino acids. Around 31% of contigs were predicted to encode secretory proteins, including some digestive and detoxifying enzymes and potential effectors. Some known salivary secreted peptides such as serine protease, cysteine proteinase inhibitors, antimicrobial peptides and venom proteins were among the top 100 highly expressed genes. Differential gene expression analysis revealed significant modulation of 850 transcripts in salivary glands upon exposure to plant roots or starvation stress. Here, we identified some venom proteins which were significantly upregulated in the salivary glands of soldier fly larvae exposed to sugarcane roots. In other insects and nematodes some of these proteins have been used to manipulate host plant defense systems and facilitate the invasion of the host plant. These findings provide a further insight into the identification of potential effector proteins involved in soldier fly-sugarcane interactions.

Intergenerational Effects of Early Life Starvation on Life-History, Consumption, and Transcriptome of a Holometabolous Insect

“…Further work could also utilize tissue-specific gene expression to determine, where gene expression changes are most prominent. For example, larvae of the soldier fly, Inopus falvus (Diptera: Stratiomyidae), differentially express numerous genes in the salivary glands in response to starvation stress (Etebari et al 2020). Other tissues of interest may be different sections of the gut.…”

“…attaining a minimum size by prolonging the larval development) (Hector and Nakagawa 2012). Moreover, starvation leads to substantial shifts in gene expression within individuals (Moskalev et al 2015; Jiang et al 2019; Etebari et al 2020; Farahani et al 2020). However, little is known how long these effects may persist (McCue et al 2017) and to which extent parental starvation may affect gene expression of offspring experiencing starvation.…”

Tripartite parasitic and symbiotic interactions as a possible mechanism of horizontal gene transfer

“…Serinetype endopeptidases have been earlier identified from the transcriptome and proteomes of H. halys, and were demonstrated to function as extra-oral digestive enzymes (Liu & Bonning, 2019;Lomate & Bonning, 2016;Peiffer & Felton, 2014), which appeared to be a prevalent feeding strategy among herbivorous hemipterans (Wright, et al 2006;Lomate & Bonning, 2016;Zhu et al, 2016). In contrast, identification of ankyrin proteins from the salivary glands/saliva of herbivorous insects was scarcely reported, except in the white-backed planthopper (Sogatella furcifera) (Miao et al, 2018), and the yellow soldier fly (Inopus flavus) (Etebari et al, 2020), with unknown functions. Serving as linkers to mediate the protein-protein interactions, ankyrin repeats play essential roles in a myriad of physiological processes in pro-and eukaryotes, including transcription and cell cycle regulation, signal transduction, and stress responses (Li et al, 2006).…”

Transcriptomic analysis of Dubas bug (Ommatissus lybicus Bergevin) infestation to Date Palm

“…In case of date palm tree, there are a few previous studies [23][24][25][26] explaining the physiology and genomics, however, very few studies have also shown the differential gene expression of date palm during abiotic stress conditions 27 . There are recent studies performed to understand the infestation process and related gene's regulation in aphid feedings to susceptible plants 28 , Ostinia furnacalis leaf feeding to maize 29,30 , soldier fly on sugarcanes in Australia, aphid attacks on wheat crops, and Lepidoptera species infection to cotton 31,32 . These studies have used detailed RNA-Seq based method to point out various underlying mechanisms during herbivory infection.…”