Transcriptomic Survey of the Midgut of Anthonomus grandis (Coleoptera: Curculionidae)

Abstract

Anthonomus grandis Boheman is a key pest in cotton crops in the New World. Its larval stage develops within the flower bud using it as food and as protection against its predators. This behavior limits the effectiveness of its control using conventional insecticide applications and biocontrol techniques. In spite of its importance, little is known about its genome sequence and, more important, its specific expression in key organs like the midgut. Total mRNA isolated from larval midguts was used for pyrosequencing. Sequence reads were assembled and annotated to generate a unigene data set. In total, 400,000 reads from A. grandis midgut with an average length of 237 bp were assembled and combined into 20,915 contigs. The assembled reads fell into 6,621 genes models. BlastX search using the NCBI-NR database showed that 3,006 unigenes had significant matches to known sequences. Gene Ontology (GO) mapping analysis evidenced that A. grandis is able to transcripts coding for proteins involved in catalytic processing of macromolecules that allows its adaptation to very different feeding source scenarios. Furthermore, transcripts encoding for proteins involved in detoxification mechanisms such as p450 genes, glutathione-S-transferase , and carboxylesterases are also expressed. This is the first report of a transcriptomic study in A. grandis and the largest set of sequence data reported for this species. These data are valuable resources to expand the knowledge of this insect group and could be used in the design of new control strategies based in molecular information.

Effect of Different Lignocellulosic Diets on Bacterial Microbiota and Hydrolytic Enzyme Activities in the Gut of the Cotton Boll Weevil (Anthonomus grandis)

“…Today, A. grandis gut transcriptome has been completely sequenced (Firmino et al, 2013; Salvador et al, 2014). In addition, several endogenous glycosyl hydrolases were identified (Salvador et al, personal communication) but the relationship between the host and its gut microbiome regarding the degradation of complex cell wall components remains unclear.…”

“…In A. grandis , most studies have focused on bio-control strategies but their microbiota has been poorly assessed (Sikorowski, 1975; Hedin et al, 1978; Firmino et al, 2013; Salvador et al, 2014). …”

Evaluation of hydrolytic enzyme activities from digestive fluids of Anthonomus grandis (Coleoptera: Curculionidae)

“…Cotton boll weevil, as other insects, harbors digestive enzymes with capacity to deconstruct and hydrolyze the plant cell wall (Ben Guerrero et al, 2016). At present, the entire transcriptome of the A. grandis midgut has been sequenced and numerous glycosyl hydrolases enzymes have been identified (Firmino et al, 2013; Salvador et al, 2014). One of them has been cloned and expressed and its β‐1,4‐endoglucanase activity has been characterized (Ibarra et al, 2019).…”

“…Cotton boll weevil (eggs, larvae, and adult) were reared in a cottonseed meal artificial diet at the Institute of Microbiology and Agricultural Zoology (IMYZA), INTA. The insects were kept at 28°C, 70% relative humidity, with a 12‐hr light/darkness photoperiod (Salvador et al, 2014). The larvae from first, second, third, and fourth instars (4, 5, 7 mm larvae and pupa, respectively) and adult were surface sterilized with 70% ethanol and dissected under a binocular microscope.…”

Spatial and temporal distribution of cotton squares and small cotton bolls fallen on ground after damage by boll weevil and the efficiency of the equipment used to collect them

“…Among these, the boll weevil Anthonomus grandis Boheman (Coleoptera: Curculionidae) is a key pest of cotton in the new world (SALVADOR et al, 2014). This insect has spread throughout the cotton-producing regions of Brazil, which has led to a severe increase in the cost of production due to economic losses arising from the insect feeding behavior and oviposition on the cotton squares and bolls (SILVA & RAMALHO, 2013).…”