Gene expression patterns of Helicoverpa armigera gut proteases.
Relative quantification of reported gut proteinase cDNAs from Helicoverpa armigera larvae fed on various host plants (cotton, chickpea, pigeonpea, tomato and okra), non-host plant PIs (winged bean, bitter gourd, ground nut, and capsicum) and during larval development has been carried out using semi-quantitative RT-PCR. Five trypsin-like and three chymotrypsin-like proteinases were categorized as insensitive or sensitive to most of the proteinase inhibitors (PIs) and insensitive/sensitive to specific PIs based on their expression analysis. These results were supported by amino acid sequence analysis, where diverged amino acids were observed in the regions, which are reported to be involved in typical trypsin-trypsin inhibitor interactions and critical for proteinase inhibitor resistance. Among exopeptidases (five aminopeptidase and three carboxypeptidase), HaAmi4 and HaAmi5 of aminopeptidase and HaCar1 of carboxypeptidase exhibited considerable differential expression. Elastase and cathepsin B-like proteinases were expressed at negligible levels. The proteases identified in the study would be ideal candidates for further interactions studies with protease inhibitors to understand the structural reasons of protease inhibitor insensitivity.
Chougule
Nanasaheb P
NP
National Chemical Laboratory, Plant Molecular Biology Unit, Division of Biochemical Sciences, Dr. Homi Bhabha Road, Pune 411 008 (MS), India.
Giri
Ashok P
AP
Sainani
Mohini N
MN
Gupta
Vidya S
VS
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D004064:Digestive System / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D007814:Larva / Q000201:enzymology; D009036:Moths / Q000201:enzymology* / Q000254:growth & development; D010447:Peptide Hydrolases / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D010447:Peptide Hydrolases