Comparison of glutathione S-transferase and general esterase in two bugs, Eurygaster integriceps Puton (Heteroptera: Scutelleridae) and Brachynema germari Kolenati (Heteroptera: Pentatomidae)

Samar RAMZI,Ali Reza BANDANI1,Arash ZIBAEE,권오석 한국곤충학회 2009 Entomological Research Vol.39 No.4

Glutathione S-transferases (GSTs) and general esterases play important roles in the detoxification of many substances including allelochemicals from plants and chemical pesticides. In this study, to determine the feeding status and effects of agronomical practices on GST and general esterase, two bug species, Eurygaster integriceps and Brachynema germari, were selected with differences in these cases. GST and general esterase responses varied when switching from 1-chloro-2,4-dinitrobenzene (CDNB) and a-naphtyl to 1,2-dichloro-4-nitro-benzene (DCNB) and b-naphtyl in E. integriceps and B. germari, respectively. The activities of GST and esterase by using CDNB and a-naphtyl were higher than that of DCNB and b-naphtyl for both insects. It was shown that the optimal pH for GST and general esterase activity varied between pH 5.5 and 6. While the Michaelis constant (Km) value related to E. integriceps toward CDNB and a-naphtyl was lower than Km for B. germari, Km values calculated for E. integriceps toward DCNB and b-naphtyl corresponding to those related to A. hejeri were similar to CDNB and a-naphtyl values. The maximal reaction velocity (Vmax) values related to E. integriceps for both substrates (CDNB and a-naphtyl) were always higher than those from B. germari and showed significant differences. At the basement of the native-PAGE electrophoresis, five bands were observed in for GST and three were visualized for B. germari, with a large, darker band for E. integriceps in the case of esterases. Studies on the detoxification enzymes of herbivores should be undertaken to determine accurately the effect of the host plants on the organisms eating them, particularly in terms of biochemical and ecological advantages.

Serine and cysteine proteases of Rhynchophorus ferrugineus (Coleoptera: Curculionidae) larvae raised on date palms (Phoenix dactylifera)

Ali Darvishzadeh,Ali Reza Bandani,Azam Amiri,Seyed Qasem Mousavi 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.3

The red palm weevil Rhynchophorus ferrugineus (Coleoptera: Curculionidae) is a serious pest of date palms in many Middle East countries. The aimof the current study was to obtain a good understanding of the gut proteolytic activity of R. ferrugineus. Thus, the enzymes in the alimentary tract were isolated and their properties were investigated using a general protease substrates (azocasein and hemoglobin) as well as specific substrates of trypsin, chymotrypsin, elastase, cathepsin L, and cathepsin B. Results showed that in the gut of the RPW both serine and cysteine proteases are present although with different activities. Among the active proteases, trypsin was the most active in the gut followed by chymotrypsin and elastase. The activities of these three proteases in the larval gut were 1.32, 1.12 and 0.32 U, respectively. Among cysteine proteases, cathepsin L and cathepsin B were active in the larval gut. The activity of cathepsin L was 0.82 U while that of cathepsin B was 0.31 U. The order of the activity of the proteases in the larval gut was trypsin N chymotrypsin N cathepsin L N elastase N cathepsin B. The effect of pH on general protease substrates hydrolysis showed two distinct peaks: one in the acidic area (pH 6.0) and another in the alkaline area (pH 10.0); these correspond to cysteine and serine protease activities, respectively. Zymogram analysis along with inhibition studies revealed that four proteases are present in the gut.

Age-specific digestion of Tenebrio molitor (Coleoptera: Tenebrionidae) and inhibition of proteolytic and amylolytic activity by plant proteinaceous seed extracts

Mehdi Dastranj,Ali Reza Bandani,Mohammad Mehrabadi 한국응용곤충학회 2013 Journal of Asia-Pacific Entomology Vol.16 No.3

Tenebrio molitor L. (Coleoptera: Tenebrionidae), is an international and serious pest of stored products. So far nothing is known about the activity for each growth stage digestive enzyme regarding this insect species. Thus, the aim of the current study was to get in depth analysis of the stage specific digestion and to investigate the effect of cereal (wheat cultivars including MV17, Aflak, Sivand, Saymon, and Zare) and legume (bean) seed extracts on the two main digestive enzymes i.e. α-amylases and proteases. Therefore, gut enzymes were extracted using distilled water and wheat cultivars and bean seed proteinaceous compounds were extracted using 0.1 M NaCl. Results showed that a steady state increase in the number and amount of digestive enzyme activities from first to fourth instar larvae was seen in both enzyme and in gel assays. In the first instar larvae (L1) only one band of α-amylase activity was seen (A1), whereas in the second (L2),third (L3), fourth (L4) and fifth (L5) instar larvae as well as in the adult (A) more than one amylase band (up to 4 isoenzymes) was seen. The same pattern was observed for α and β glucosidases and proteases. Probit analysis showed that bean and MV17 inhibited the amylase activity with an I50 of 9.73 and 7.4 μg, respectively. The same cultivar seed extract inhibited protease activity with I50s of 11.54 and 6.5 μg proteins. It is concluded that proteinaceous extract of cereals and bean seeds have a strong potential to be used in this pest management.

Temperature and Ca2+ ion as modulators in cellular immunity of the Sunn pest Eurygaster integriceps Puton (Heteroptera: Scutelleridae)

Arash ZIBAEE,Ali Reza BANDANI,Reza TALAEI-HASSANLOUEI,Davide MALAGOLI 한국곤충학회 2009 Entomological Research Vol.39 No.6

Environmental conditions in addition to divalent cations may affect the interactions between pathogens and insects. Elucidation of factors which modulate insect immune responses could be a significant part of investigations in this area. In this study, adults of Eurygaster integriceps, as the destructive pest of wheat, were kept at different temperatures in addition to injection with different concentrations of Ca2+ to find the effect on cellular immune reactions against Beauveria bassiana. Results showed that total and differentiate hemocyte numbers, nodule formation and phenoloxidase activity increased with elevation of temperature so that the higher values were obtained at 30 and 40°C at various intervals. Higher concentrations of Ca2+ ion (5 mM) caused an increase in plasmatocyte length and width especially after 60 min. Similar results were observed for nodule formation and phenoloxidase activity of E. integriceps adults after injection by B. bassiana spores and phenoloxidase activity. It is clear from the current study that thermoregulation and Ca2+ ion can positively affect the hemocyte numbers especially plasmatocytes and granulocytes, nodule formation and phenoloxidase activity in E. integriceps. The understanding of modulators of the insect immune response may directly influence novel approaches to obtain safe and effective biological control agents.

Characterization of α-amylase in the midgut and the salivary glands of rice striped stem borer, Chilo suppressalis Walker (Lepidoptera: Pyralidae)

Arash Zibaee,Ali Reza Bandani,Maryam Kafil,Samar Ramzi 한국응용곤충학회 2008 Journal of Asia-Pacific Entomology Vol.11 No.4

The rice striped stem borer, Chilo supprressalis, is a destructive pest of rice that was introduced to Iran in 1973 and has since become widely distributed. Amylases are hydrolytic enzymes that catalyze the hydrolysis of the α-D-(1,4)-glucan linkage in glycogen and other related carbohydrates. Laboratory-reared 4th stadium larvae were randomly selected; the midgut and the salivary glands were removed by dissection under a dissecting microscope and α-amylase activity was assayed using the dinitrosalicylic acid procedure. The activity of α-amylase in the midgut and salivary gland were 0.06 and 0.036 μmol/min/mg protein, respectively. The optimal pH and temperature for α-amylase were 9 and 35–40 °C, which is consistent with reports of other lepidopteran insects. The enzyme activity was inhibited by addition of NaCl, KCl, MgCl2, Urea, EDTA, and SDS. CaCl2 enhanced enzyme activity. Ca2+ ions also had inhibitory effects on glucosidase activity. Plant amylase inhibitors play important role against insect pests. Hence, the characterization of digestive enzymes and the examination of inhibitors on enzyme activity could be useful in tackling of insect pests. The rice striped stem borer, Chilo supprressalis, is a destructive pest of rice that was introduced to Iran in 1973 and has since become widely distributed. Amylases are hydrolytic enzymes that catalyze the hydrolysis of the α-D-(1,4)-glucan linkage in glycogen and other related carbohydrates. Laboratory-reared 4th stadium larvae were randomly selected; the midgut and the salivary glands were removed by dissection under a dissecting microscope and α-amylase activity was assayed using the dinitrosalicylic acid procedure. The activity of α-amylase in the midgut and salivary gland were 0.06 and 0.036 μmol/min/mg protein, respectively. The optimal pH and temperature for α-amylase were 9 and 35–40 °C, which is consistent with reports of other lepidopteran insects. The enzyme activity was inhibited by addition of NaCl, KCl, MgCl2, Urea, EDTA, and SDS. CaCl2 enhanced enzyme activity. Ca2+ ions also had inhibitory effects on glucosidase activity. Plant amylase inhibitors play important role against insect pests. Hence, the characterization of digestive enzymes and the examination of inhibitors on enzyme activity could be useful in tackling of insect pests.

Combination of antibiotics and chitin synthesis inhibitors for the control of Microcerotermes diversus (Isoptera: Termitidae)

Qasem Mousavi Seyed,Reza Bandani Ali,Alaie Ebrahim 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.4

The symbiotic microorganisms in the gut of termites play a key role in the digestion of cellulose and nitrogen metabolism. Therefore, disruption of these symbioses activity can open a door toward termite management. Thus, the current study aimed to exploit termite gut bacterial capacity in order to utilize it for efficient termite control. So, in the current study, gut bacteria of Microcerotermes diversus have been extracted, cultivated on both liquid and solid media, and screened with a range of antibiotics to find the most effective antibiotics. Results showed that chloramphenicol and nalidixic acid were the most effective antibiotics in preventing the colony unit formation of the gut bacteria amongst 16 antibiotics tested. Also, from two chitin synthesis inhibitors tested hexaflumuron with an LC 50 of 613.9 µg ml −1 was more toxic than lufenuron with an LC 50 of 1414.5 µg ml −1 . Thus, two antibiotics (chloramphenicol and nalidixic acid) were used simultaneously with a sub-lethal con centration of hexaflumuron against the termite and a variety of factors such as wood consumption rate, running speed, body water content, and tunneling activity were evaluated under laboratory conditions. Results showed that the combination of these two antibiotics (chloramphenicol and nalidixic acid) with hexaflumuron caused a significant decrease in termite consumption rate, running speed, and tunneling behavior, but didn’t affect the body water contents of termites. These results suggest that using a combination of antibiotic/s and hexaflumuron is a promising management practice to get a suitable control measure for the studied termite.