The trypsin inhibitor pro-peptide induces toxic effects in Indianmeal moth, Plodia interpunctella

2021

Bull. Entomol. Res.

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Spodoptera littoralis (Boisd) is globally recognized as a destructive polyphagous insect pest of various crops in the world. It is commonly managed by chemical pesticides, which can cause deleterious effects such as environmental pollution, toxicity to non-target organisms and the emergence of secondary pests. Hence, investigations into alternative pest control strategies such as the use of resistant host plant cultivar against S. littoralis is important. This study aimed to explore the nutritional performance of S. littoralis larvae in dependence on total anthocyanin, flavonoid, and phenol levels across 11 bean cultivars (Phaseolus and Vigna spp.) under laboratory conditions. The results revealed that the Mashhad cultivar accumulated the highest amount of total phenols (13.59 mg ml−1), whereas Yaghout and Arabi cultivars posed the lowest total phenols contents (1.80 and 1.90 mg ml−1, respectively). Across larval instars (third to sixth), the highest consumption index and relative consumption rate were recorded on the Mashhad cultivar. The lowest values of efficiency of conversion of ingested food and the efficiency of conversion of digested food of total larval instars were detected in the larvae which were reared on the Mashhad cultivar. Likewise, the lowest value of the index of plant quality (IPQ) was obtained in the Mashhad cultivar; however, IPQ was figured out at the highest level in the Arabi cultivar. Our findings show that the differential accumulation of secondary metabolites would change the nutritional quality of plants for S. littoralis. Based on the findings, the Mashhad cultivar may serve as a candidate for either integrated pest management or breeding programs aiming at controlling this pest.

Section: Discussionmentioning

confidence: 99%

Investigation of secondary metabolites in bean cultivars and their impact on the nutritional performance ofSpodoptera littoralis(Lep.: Noctuidae)

Shishehbor

2021

Bull. Entomol. Res.

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“…To compensate, insect herbivores increase production of digestive enzymes or upregulate production of inhibitor-insensitive enzymes in the midgut [ 42 , 43 , 44 ]. Plant protease inhibitors (PIs) are an essential group of defensive compounds commonly found in plant storage organs such as seeds and tubers, which limit assimilation of dietary proteins [ 22 , 45 ]. In addition to protease inhibitors, amylase inhibitors are commonly found in plants, and their inhibitory effect on the activity of digestive amylases in insects reduces digestibility of starchy compounds [ 46 , 47 , 48 , 49 ].…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, assessment of the biochemical metabolites characterizing potential selections for cultivation may help explain differences in demographic and physiological responses of herbivores and assist in selection of resistance traits [ 13 , 20 ]. For example, elucidating digestive physiology of pests has benefited development of target-specific insecticides [ 21 , 22 , 23 ]. Highly polyphagous herbivores, such as S. littoralis , have sophisticated mechanism(s) to regulate their digestive proteases [ 24 ]; midgut proteases as well as α-amylases are two groups that may prove particularly important for digestion of legumes [ 25 ].…”

Section: Introductionmentioning

confidence: 99%

Life Table Parameters and Digestive Enzyme Activity of Spodoptera littoralis (Boisd) (Lepidoptera: Noctuidae) on Selected Legume Cultivars

Shishehbor

Stelinski

2022

Insects

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Spodoptera littoralis (Boisd) is a highly destructive pest that attacks a large number of economically important crops. We examined life table parameters as well as activity of major digestive enzymes of S. littoralis larvae in response to protein and starch contents across 11 legume cultivars to identify potential resistance traits. The results showed that S. littoralis reared on the common bean, Arabi, displayed the highest intrinsic rate of increase (r), while the lowest was recorded on the cowpea, Mashhad. Also, the highest net reproductive rate (R0) was obtained in those insects reared on the Arabi cultivar. Larvae displayed the highest and lowest proteolytic activities when fed on Mashhad and Arabi cultivars, respectively. The highest amylolytic activity was quantified in larvae that fed on the Arabi and 1057 cultivars, while the lowest occurred in larvae feeding on Yaghout and Mashhad cultivars. Developmental time of S. littoralis larvae was negatively correlated with protein content, while amylolytic activity was positively correlated with starch content of legumes. Our findings indicate that Arabi was a susceptible cultivar, while Mashhad exhibited tolerance traits against S. littoralis. These results should facilitate selection of legume cultivars for production or breeding efforts that involve S. littoralis management.

“…The pro-region of proteases is required for the proper folding of the protease domain and can also function as a potent inhibitor of the mature enzyme [ [27] , [28] , [29] ]. Amino acid sequences of multiple pro-regions and other naturally occurring protease inhibitors from different insect species were obtained from the national center for biotechnology information (NCBI) ( http://www.ncbi.nlm.nih.gov/ ) and Uniprot databases.…”

Section: Methodsmentioning

confidence: 99%

Insect protease inhibitors; promising inhibitory compounds against SARS-CoV-2 main protease

Computers in Biology and Medicine

Tabein

2022

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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has adversely affected global health since its emergence in 2019. The lack of effective treatments prompted worldwide efforts to immediately develop therapeutic strategies against COVID-19. The main protease (M pro ) of SARS-CoV-2 plays a crucial role in viral replication, and therefore it serves as an attractive target for COVID-19-specific drug development. Due to the richness and diversity of insect protease inhibitors, we docked SARS-CoV-2 M pro onto 25 publicly accessible insect-derived protease inhibitors using the ClusPro server, and the regions with high inhibitory potentials against M pro were used to design peptides. Interactions of these inhibitory peptides with M pro were further assessed by two directed docking programs, AutoDock and Haddock. AutoDock analysis predicted the highest binding energy (−9.39 kcal/mol) and the lowest inhibition constant (130 nM) for the peptide 1KJ0-7 derived from SGCI ( Schistocerca gregaria chymotrypsin inhibitor). On the other hand, Haddock analysis resulted in the discovery of a different peptide designated 2ERW-9 from infestin, a serine protease inhibitor of Triatoma infestans , with the best docking score (−131), binding energy (−11.7 kcal/mol), and dissociation constant (2.6E-09 M) for M pro . Furthermore, using molecular dynamic simulations, 1KJ0-7 and 2ERW-9 were demonstrated to form stable complexes with M pro . The peptides also showed suitable drug-likeness properties compared to commercially available drugs based on Lipinski's rule. Our findings present two peptides with possible protease inhibitor activities against M pro and further demonstrate the potential of insect-derived peptides and computer-aided methods for drug discovery.