Midgut juice of Plutellaxylostella highly resistant to Bacillus thuringiensis Cry1Ac contains a three times larger amount of glucosinolate sulfatase which binds to Cry1Ac compared to that of susceptible strain

• Published in: Pesticide biochemistry and physiology Vol. 101; no. 2; pp. 125 - 131
• Main Authors: Yamazaki, Takanori, Ishikawa, Toshiki, Pandian, Ganesh N, Okazaki, Keiichi, Haginoya, Kohsuke, Tachikawa, Yuka, Mitsui, Toshiaki, Miyamoto, Kazuhisa, Angusthanasombat, Chanan, Hori, Hidetaka
• Format: Journal Article
• Language: English
• Published: 01.10.2011
• Subjects: Cry1Ac toxin; Glucosinolates; Juices; Midgut; Pesticides; Plutella xylostella
• ISSN: 0048-3575
• DOI: 10.1016/j.pestbp.2011.09.001

Midgut juice of Plutellaxylostella strain PXR which is resistant to Cry1Ac was biochemically characterized relative to the susceptible PXS strain. The midgut juice of PXR (PXR-Juice) was shown to process Cry1Ac protoxin to 60 kDa active toxin with the same processing pattern as that of juice from PXS (PXS-Juice) in SDSPAGE. PXS larvae which were given the Cry1Ac toxin pre-processed with PXR-Juice were killed with the same rate as that with Cry1Ac pre-activated by trypsin. PXR-Juice was found to contain three times larger amount of 66 kDa protein (P66) than PXS-Juice and the N-terminal amino acid sequence of P66 was matched to that of glucosinolate sulfatase in data base search. The protein band of P66 was coincided with the band of p-nitro phenyl sulfatase activity in zymogram. P66 purified to homogeneity in SDS-PAGE bound to Cry1Ac and soybean agglutinin, and K sub(D) for Cry1Ac was estimated to be 718 nM with surface plasmon resonance analysis. Using purified sulfatase, K sub(m) and V sub(max) were estimated and involvement of the enzyme in the PXR resistance was discussed.