Biochemical response between insects and plants: an investigation of enzyme activity in the digestive system of Leucoptera coffeella (Lepidoptera: Lyonetiidae) and leaves of Coffea arabica (Rubiaceae) after herbivory

The economic loss in soybean crops caused by the Lepidoptera insects has encouraged the search for new strategies to control this pest, which are currently based on synthetic insecticides. This paper evaluated the ability of ApTI (Adenanthera pavonina trypsin inhibitor) to inhibit trypsin-like proteins from Anticarsia gemmatalis by docking, molecular dynamics, and enzymatic and survival assay. The docking and molecular dynamic simulation between trypsin and ApTI were performed using the program CLUSPRO and NAMD, respectively. The inhibitory constant K i and the inhibition type were determined through chromogenic assays. The survival assay of neonatal larvae under treatment with artificial diet supplemented with ApTI was also performed. The ApTI binding site was predicted to block substrate access to trypsin due to four interactions with the enzyme, producing a complex with a surface area of 1,183.7 Å 2 .The kinetic analysis revealed a noncompetitive tightbinding mechanism. The survival curves obtained using Kaplan-Meier estimators indicated that the highest larvae mortality was 60%, using 1.2 mg of ApTI per 100 ml of artificial diet. The in vitro, in vivo, and in silico studies demonstrated that ApTI is a strong noncompetitive inhibitor of trypsin with biotechnological potential for the control of A. gemmatalis insect. K E Y W O R D S binding, insects, Kunitz inhibitor, molecular docking, noncompetitive, trypsin enzyme

Section: Discussionmentioning

confidence: 99%

“…The purification was performed and analyzed according to Macedo et al (2007) and Macedo et al (2004), obtaining the inhibitor with 98% purity. This inhibitor was chosen by the ability of inhibition reported in previous studies (Meriño‐Cabrera et al, 2018).…”

Section: Methodsmentioning

confidence: 99%

Noncompetitive tight‐binding inhibition ofAnticarsia gemmatalistrypsins byAdenanthera pavoninaprotease inhibitor affects larvae survival

Meriño‐Cabrera

Mendes

Castro

et al. 2020

“…Highly applied technology provides increased automation, mechanization, and productivity. However, the soybean yield is still limited by biotic factors, such as agricultural pests, which cause great damage to this crop (Meriño‐Cabrera et al, ). The soybean caterpillar is a key plague of soybeans due to the great economic losses that it causes to the crop.…”

Section: Introductionmentioning

confidence: 99%

“…On the contrary, plants have developed multiple dynamic coevolutionary strategies of defense against phytophagous. In this interaction, plants can produce several protease inhibitors (PIs) and secondary metabolites (phytochemicals) via lipoxygenases, which affect the performance and resistance of herbivores (Feussner & Wasternack, ; Meriño‐Cabrera et al, ; Pilon et al, ).…”

Section: Introductionmentioning

confidence: 99%

“…PIs contribute up to 10% of the total protein content, generally present in a higher proportion in the reserve tissues and also detectable in leaves in response to insect attack (Meriño‐Cabrera et al, ; Pilon, Visôtto, Guedes, & Oliveira, ). In this sense, PIs can serve as pest control agents, either in the pulverized form or in transgenic plants that highly express these PIs (Meriño‐Cabrera et al, ; Pilon et al, ). Taking into account that the need for more appropriate formulations has raised the cost of agrochemicals over the years, interest in research into ecologically sound pesticides has increased (Krinski, Foerster, & Deschamps, ).…”

Section: Introductionmentioning

confidence: 99%

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Intestinal proteolytic profile changes during larval development of Anticarsia gemmatalis caterpillars

Junior

Vital

Barros

et al. 2019

Soybean is one of most consumed and produced grains in the world, and Anticarsia gemmatalis is a pest that causes great damage to this crop due to severe defoliation during its larval phase. Plants have mechanisms that lead to the inhibition of proteases in the intestine of these herbivores, hampering their development. Understanding this complex protease inhibitor is important for pest control. The objective of this study was to evaluate the enzymatic profiles of the intestinal proteases of the soybean caterpillar at different instars. For this, the proteolytic profile of the gut in the third, fourth, and fifth instars were analyzed.Irreversible inhibitors of proteases were separately incubated with A. gemmatalis enzyme extracts at the third, fourth, and fifth instar to assess the contribution of these proteases to total proteolytic activity. The enzymatic extracts were also evaluated with specific substrates to confirm changes in the specific activities of trypsin-like, chymotrypsin-like, and cysteine proteases at different instars. The results showed that the protease profile of A.gemmatalis gut changes throughout its larval development.The activity of cysteine proteases was more intense in the first instar. On the contrary, the serine proteases The protease profile of the gut of A. gemmatalis changes throughout larval development. In the third instar, cysteine protease activity is predominant over others. In the fourth and fifth instars, proteolytic activity is mainly due to serine proteases. This difference in activity in the different instars of A. gemmatalis suggests that the expression of the genes coding for proteases also changes throughout the development of the insect. Using serine PIs is a good strategy for controlling insect pests, as these are the main proteolytic enzymes of Lepidoptera. However, the presence of other important protease subclasses in insect digestibility suggests that a combination of serine and cysteine PIs may be promising, aiming to compromise larval development at different instars.

Larval development and proteolytic activity of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) exposed to different soybean protease inhibitors

Mendonça

Barros

Cordeiro

et al. 2019

Anticarsia gemmatalis represents a relevant factor for lowering soybean and other legume crop productivities.Protease inhibitors affect protein degradation and reduce the availability of amino acids, impairing the development and survival of insect pests. To evaluate the possible use of proteinaceous protease inhibitors in the management of this pest, the activities of midgut proteases and the growth and development of A. gemmatalis larvae exposed to soybean Bowman-Birk trypsin-chymotrypsin inhibitor (SBBI) and soybean Kunitz trypsin inhibitor (SKTI) were determined. The survival curves obtained using Kaplan-Meier estimators indicated that SKTI and SBBI stimulated larval survival. However, the development of A.gemmatalis was delayed, and prepupal weight decreased in the presence of both inhibitors. The results showed that SKTI and SBBI inhibited the trypsin-like and total proteolytic activities of larvae on the 12th day after eclosion. On the 15th day after eclosion, larvae exposed to SKTI increased the activities of trypsin and total proteases.Although SKTI and SBBI did not affect the survival of the insect, they had effects on midgut proteases in a stage wherein A. gemmatalis fed voraciously, increased the larval cycle, and decreased prepupal weight. These findings provide baseline information about the potential of proteinaceous protease inhibitors to manage the velvetbean caterpillar, avoiding chemical pesticides.K E Y W O R D S biotic stress, insect attack, insect performance, protease inhibitory