Journal ArticleDOI
α-Amylase Activities in Larval Midgut Extracts from Four Species of Lepidoptera (Tortricidae and Gelechiidae): Response to pH and to Inhibitors from Wheat, Barley, Kidney Bean, and Streptomyces
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TLDR
Levels of α-amylase activity between 0.6 and 5.0 µmoles maltose minute-1 gram insect-1 occurred in larval midgut extracts from 4 species of lepidopterous pests and the optima for activity at a highly alkaline pH range was described.Abstract:
Levels of α-amylase activity between 0.6 and 5.0 µmoles maltose minute-1 gram insect-1 occurred in larval midgut extracts from 4 species of lepidopterous pests-light brown apple moth, Epiphyas postvittana (Walker), Planotortrix octo (Dugdale), and Ctenopseustis Obliquana (Walker) are pests of apple leaves and fruit, and potato tuber moth, Phthorimaea Operculella (Zeller), is a pest of potato tubers and foliage. Activity response curves described the optima for activity at a highly alkaline pH range (pH 10.5 in leafrollers and pH 9.5 in potato tuber moth). This result is consistent with the known high midgut pH in other species of Lepidoptera and with the pH optima of their digestive proteases. The 3 wheat derived α-amylase inhibitors inhibited enzyme activities of all 4 species of Lepidoptera, but the other 3 (barley tetramer, Streptomyces , and kidney bean inhibitors) had no effect. Wheat dimeric inhibitor (30 µM) completely inhibited α-amylase activity in potato tuber moth midgut extracts.read more
Citations
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Journal ArticleDOI
Responses of midgut amylases of Helicoverpa armigera to feeding on various host plants.
TL;DR: Correlation of amylase and proteinase activities of H. armigera with the protein and carbohydrate content of various diets suggested that H.Armigera regulates the levels of these digestive enzymes in response to macromolecular composition of the diet.
Journal ArticleDOI
The diamondback moth, Plutella xylostella, specifically inactivates Mustard Trypsin Inhibitor 2 (MTI2) to overcome host plant defence
TL;DR: It appears that the insensitivity of the diamondback moth toMTI2 can be sufficiently explained by the specific degradation of MTI2, thereby protecting itself against this protease inhibitor which is part of the defense of cruciferous plant species.
Journal ArticleDOI
Digestive α-amylases from Tecia solanivora larvae (Lepidoptera: Gelechiidae) : response to pH, temperature and plant amylase inhibitors
TL;DR: The results show that the alpha-amylase inhibitor from amaranth seeds may be a better candidate to make genetically-modified potatoes resistant to this insect than inhibitors from common bean seeds.
Journal ArticleDOI
Expressed sequence tags from the midgut of Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae)
Robert M. Simpson,Richard D. Newcomb,H.S. Gatehouse,R.N. Crowhurst,David Chagné,L. N. Gatehouse,Ngaire P. Markwick,Lesley L. Beuning,C. Murray,Sean D. G. Marshall,Yar-Khing Yauk,Bhawana Nain,Y.-Y. Wang,Andrew P. Gleave,John T. Christeller +14 more
TL;DR: The identity of the most common Interpro families correlates well with major known functions of the midgut and two of the larger multigene families, serine proteases and lipases, expressed a high proportion of genes that are likely to be catalytically inactive.
Journal ArticleDOI
Biochemical characterization of digestive proteases and carbohydrases of the carob moth, Ectomyelois ceratoniae (Zeller) (Lepidoptera: Pyralidae)
TL;DR: Digestive proteinases and carbohydrases of Ectomyelois ceratoniae (Zeller) larvae were investigated using appropriate substrates and inhibitors and revealed at least four, two, and one isozymes for trypsin, chymotrypsin-, and elastase-like activities respectively.
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