A plant defensive cystatin (soyacystatin) targets cathepsin L‐like digestive cysteine proteinases (DvCALs) in the larval midgut of western corn rootworm (Diabrotica virgifera virgifera) Academic Article uri icon

abstract

  • Feeding bioassay results established that the soybean cysteine proteinase inhibitor N (soyacystatin N, scN) substantially inhibits growth and development of western corn rootworm (WCR), by attenuating digestive proteolysis [Zhao, Y. et al. (1996) Plant Physiol. 111, 1299-1306]. Recombinant scN was more inhibitory than the potent and broad specificity cysteine proteinase inhibitor E-64. WCR digestive proteolytic activity was separated by mildly denaturing SDS-PAGE into two fractions and in-gel assays confirmed that the proteinase activities of each were largely scN-sensitive. Since binding affinity to the target proteinase [Koiwa, H. et al. (1998) Plant J. 14, 371-380] governs the effectiveness of scN as a proteinase inhibitor and an insecticide, five peptides (28-33 kDa) were isolated from WCR gut extracts by scN affinity chromatographic separation. Analysis of the N-terminal sequence of these peptides revealed similarity to a cathepsin L-like cysteine proteinase (DvCAL1, Diabrotica virgifera virgifera cathepsin L) encoded by a WCR cDNA. Our results indicate that cathepsin L orthologs are pivotal digestive proteinases of WCR larvae, and are targets of plant defensive cystatins (phytocystatins), like scN.

altmetric score

  • 6

author list (cited authors)

  • Koiwa, H., Shade, R. E., Zhu-Salzman, K., D'Urzo, M. P., Murdock, L. L., Bressan, R. A., & Hasegawa, P. M.

citation count

  • 87

publication date

  • April 2000

publisher