Higher accumulation of proteinase inhibitors in flowers than leaves and fruits as a possible basis for differential feeding preference of Helicoverpa armigera on tomato (Lycopersicon esculentum Mill, Cv. Dhanashree).
Tomato (Lycopersicon esculentum, Mill; cultivar- Dhanashree) proteinase inhibitors (PIs) were tested for their trypsin inhibitory (TI) and Helicoverpa armigera gut proteinases inhibitory (HGPI) activity in different organs of the tomato plants. Analysis of TI and HGPI distribution in various parts of the plant showed that flowers accumulated about 300 and 1000 times higher levels of TI while 700 and 400 times higher levels of HGPI as compared to those in leaves and fruits, respectively. Field observation that H. armigera larvae infest leaves and fruits but not the flowers could be at least partially attributed to the protective role-played by the higher levels of PIs in the flower tissue. Tomato PIs inhibited about 50-80% HGP activity of H. armigera larvae feeding on various host plants including tomato, of larvae exposed to non-host plant PIs and of various larval instars. Tomato PIs were found to be highly stable to insect proteinases wherein incubation of inhibitor with HGP even for 3h at optimum conditions did not affect inhibitory activity. Bioassay using H. armigera larvae fed on artificial diet containing tomato PIs revealed adverse effect on larval growth, pupae development, adult formation and fecundity.
Damle
Mrunal S
MS
Plant Molecular Biology Unit, Division of Biochemical Sciences, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, Maharashtra 411 008, India.
Giri
Ashok P
AP
Sainani
Mohini N
MN
Gupta
Vidya S
VS
D000818:Animals; D002417:Cattle; D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000378:metabolism; D035264:Flowers / Q000737:chemistry / Q000378:metabolism*; D005518:Food Preferences; D005638:Fruit / Q000737:chemistry / Q000378:metabolism*; D018551:Solanum lycopersicum / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism* / Q000469:parasitology; D009036:Moths / Q000254:growth & development / Q000502:physiology*; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism*; D011480:Protease Inhibitors / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D014357:Trypsin / Q000378:metabolism; D014361:Trypsin Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology
D011480:Protease Inhibitors; D014361:Trypsin Inhibitors; D002918:Chymotrypsin; D014357:Trypsin