Open AccessBacillus thuringiensis chimeric proteins Cry1A.2 and Cry1B.2 to control soybean lepidopteran pests: New domain combinations enhance insecticidal spectrum of activity and novel receptor contributions
Author(s) -
Danqi Chen,
William J. Moar,
Agoston Jerga,
A. S. Prakasha Gowda,
Jason Milligan,
Eric C. Bretsynder,
T.J. Rydel,
James A. Baum,
Altair Arlindo Semeão,
Xiaoran Fu,
Victor M. Guzov,
Karen K. Gabbert,
Graham P. Head,
Jeffrey A. Haas
Publication year - 2021
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0249150
Subject(s) - bacillus thuringiensis , biology , anticarsia gemmatalis , helicoverpa armigera , caterpillar , cry1ac , biopesticide , lepidoptera genitalia , noctuidae , bioassay , trichoplusia , spodoptera , genetically modified crops , botany , agronomy , recombinant dna , transgene , pesticide , gene , genetics , bacteria
Two new chimeric Bacillus thuringiensis (Bt) proteins, Cry1A.2 and Cry1B.2, were constructed using specific domains, which provide insecticidal activity against key lepidopteran soybean pests while minimizing receptor overlaps between themselves, current, and soon to be commercialized plant incorporated protectants (PIP’s) in soybean. Results from insect diet bioassays demonstrate that the recombinant Cry1A.2 and Cry1B.2 are toxic to soybean looper (SBL) Chrysodeixis includens Walker, velvetbean caterpillar (VBC) Anticarsia gemmatalis Hubner, southern armyworm (SAW) Spodoptera eridania , and black armyworm (BLAW) Spodoptera cosmioides with LC 50 values < 3,448 ng/cm 2 . Cry1B.2 is of moderate activity with significant mortality and stunting at > 3,448 ng/cm 2 , while Cry1A.2 lacks toxicity against old-world bollworm (OWB) Helicoverpa armigera . Results from disabled insecticidal protein (DIP) bioassays suggest that receptor utilization of Cry1A.2 and Cry1B.2 proteins are distinct from each other and from current, and yet to be commercially available, Bt proteins in soy such as Cry1Ac, Cry1A.105, Cry1F.842, Cry2Ab2 and Vip3A. However, as Cry1A.2 contains a domain common to at least one commercial soybean Bt protein, resistance to this common domain in a current commercial soybean Bt protein could possibly confer at least partial cross resistance to Cry1A2. Therefore, Cry1A.2 and Cry1B.2 should provide two new tools for controlling many of the major soybean insect pests described above.