Zymograms as a Tool to Detect PPIs in Host Plants of Antheraea assamensis

Abstract

Antheraea assamensis (vernacular: ‘muga’) larvae is commercially reared on two tree species of the Lauraceae family, Persea bombycina and Litsea monopetala for its golden yellow, lustrous cocoon silk. Biochemical and molecular studies suggested that the midgut digestive enzymes and their transcripts in larvae feeding on P. bombycina differ from those found in larvae feeding on L. monopetala indicating that host plant 'choice' affects the digestive physiology of this insect. Ingestion of plant proteinase inhibitors is known to influence expression of digestive enzymes. Using reverse zymography technique trypsin and chymotrypsin inhibitors were detected in herbivore-induced leaves of L. monopetala and P. bombycina that could inhibit midgut proteinases of A. assamensis. Such interactions may affect proteolytic digestion in larvae reared on different host plant species. This work may have significance in quality of silk produced by muga silkworm, ultimately benefiting the silkworm rearers/industry.