Comparative Transcriptome Analysis to Reveal Differentially Expressed Cytochrome P450 in Response to Imidacloprid in the Aphid Lion, Chrysoperla zastrowi sillemi (Esben-Petersen).

The aphid lion, Chrysoperla zastrowi sillemi (Neuroptera: Chrysopidae) is a highly effective beneficial predator of many agricultural pests and has developed resistance to several insecticides. Understanding the molecular mechanism of insecticide resistance in the predators is crucial for its effective application in IPM programs. Therefore, transcriptomes of imidacloprid-resistant and susceptible strains have been assessed using RNA-seq. Cytochrome P450 is one of the important gene families involved in xenobiotic metabolism. Hence, our study focused on the CYP gene family where mining, nomenclature, and phylogenetic analysis revealed a total of 95 unique CYP genes with considerable expansion in CYP3 and CYP4 clans. Further, differential gene expression (DGE) analysis revealed ten CYP genes from CYP3 and CYP4 clans to be differentially expressed, out of which nine genes (CYP4419A1, CYP4XK1, CYP4416A10, CYP4416A-fragment8, CYP6YL1, CYP6YH6, CYP9GK-fragment16, CYP9GN2, CYP9GK6) were downregulated and one (CYP9GK3) was upregulated in the resistant strain as compared to the susceptible strain. Expression validation by quantitative real-time PCR (qRT-PCR) is consistent with the DGE results. The expansion and differential expression of CYP genes may be an indicator of the capacity of the predator to detoxify a particular group of insecticides.

Deciphering the Molecular Mechanisms of Insecticide Resistance From the Transcriptome Data of Field Evolved Spinosad Resistant and Susceptible Populations of Plutella xylostella (Lepidoptera: Plutellidae).

Diamondback moth, Plutella xylostella is a serious pest of cruciferous vegetables and causes substantial economic loss all over the world. This study was undertaken to decipher the molecular mechanisms involved in the field evolved insecticide resistance in P. xylostella upon exposure to spinosad. To do so, spinosad-resistant and susceptible larval populations were subjected to transcriptome analysis using Illumina paired-end sequencing. De novo assembly was generated from raw reads of both the samples which resulted in the identification of 41,205 unigenes. Functional annotation and digital gene expression analysis were carried out to determine the differentially expressed genes. 1,348 unigenes were found to have a significant differential expression in the resistant population. Several genes involved in insecticide resistance like CYP P450, GSTs, small heat shock protein, and UDP glycosyltransferase were found to be up-regulated while genes related to mitochondrial energy metabolism and cuticular processes were down-regulated. Further, gene mining and phylogenetic analysis of two important gene families namely, CYP and GSTs were performed and the results revealed that these genes could play a major role in the development of field evolved spinosad resistance in P. xylostella by gene duplication and differential gene expression.

In Silico evaluation and identification of fungi capable of producing endo-inulinase enzyme.

The enzyme endo-inulinase hydrolyzes inulin to short chain fructooligosaccharides (FOS) that are potential prebiotics with many health promoting benefits. Although the raw materials for inulin production are inexpensive and readily available, commercial production of FOS from inulin is limited due to inadequate availability of the enzyme source. This study aimed to identify the fungi capable of producing endo-inulinase based on the in silico analysis of proteins retrieved from non-redundant protein sequence database. The endo-inulinase of Aspergillus ficuum was used as reference sequence. The amino acid sequences with >90% sequence coverage, belonging to different fungi were retrieved from the database and used for constructing three-dimensional (3D) protein models using SWISS-MODEL and Bagheerath H. The 3D models of comparable quality as that of the reference endo-inulinase were selected based on QMEAN Z score. The selected models were evaluated and validated for different structural and functional qualities using Pro-Q, ProSA, PSN-QA, VERIFY-3D, PROCHECK, PROTSAV metaserver, STRAP, molecular docking, and molecular dynamic simulation analyses. A total of 230 proteins belonging to 53 fungal species exhibited sequence coverage >90%. Sixty one protein sequences with >60% sequence identity were modeled as endo-inulinase with higher QMEAN Z Score. The evaluations and validations of these 61 selected models for different structural and functional qualities revealed that 60 models belonging to 22 fungal species exhibited native like structure and unique motifs and residues as that of the reference endo-inulinase. Further, these models also exhibited similar kind of interaction between the active site around the conserved glutamate residue and substrate as that of the reference endo-inulinase. In conclusion, based on the current study, 22 fungal species could be identified as endo-inulinase producer. Nevertheless, further biological assessment of their capability for producing endo-inulinase is imminent if they are to be used for commercial endo-inulinase production for application in FOS industry.