Bacillus thuringiensis toxins with nematocidal activity against the pinewood nematode Bursaphelenchus xylophilus

Yajie Guo; Mingqing Weng; Yunzhu Sun; Rebeca Carballar-Lejarazú; Songqing Wu; Chunlan Lian

doi:10.1016/j.jip.2022.107726

Bacillus thuringiensis toxins with nematocidal activity against the pinewood nematode Bursaphelenchus xylophilus

J Invertebr Pathol. 2022 Mar:189:107726. doi: 10.1016/j.jip.2022.107726. Epub 2022 Feb 3.

Authors

Yajie Guo¹, Mingqing Weng², Yunzhu Sun², Rebeca Carballar-Lejarazú³, Songqing Wu⁴, Chunlan Lian⁵

Affiliations

¹ Asian Research Center for Bioresource and Environmental Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 188-0002, Japan; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou 350000, China.
² College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350000, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou 350000, China.
³ Department of Microbiology and Molecular Genetics, University of California, Irvine, CA 92697-4025, USA.
⁴ College of Forestry, Fujian Agriculture and Forestry University, Fuzhou 350000, China; Key Laboratory of Integrated Pest Management in Ecological Forests, Fujian Province University, Fujian Agriculture and Forestry University, Fuzhou 350000, China. Electronic address: dabinyang@126.com.
⁵ Asian Research Center for Bioresource and Environmental Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 188-0002, Japan.

PMID: 35122837
DOI: 10.1016/j.jip.2022.107726

Abstract

The pine wilt disease is caused by the pinewood nematode Bursaphelenchus xylophilus and it results in serious ecological and economic losses. Therefore, effective prevention and control methods for the pinewood nematode are urgently required. Bacillus thuringiensis (Bt), a widely used microbial insecticide, produces toxins that are toxic to several species of parasitic nematodes, however, its effects on B. xylophilus have not been determined. In this study, Cry5Ba3, App6Aa2, Cry12Aa1, Cry13Aa1, Cry14Aa1, Cry21Aa3, Cry21Fa1, Xpp55Aa1, and Cyt8Aa1 toxins' nematocidal activity against B. xylophilus was evaluated, six toxins with high toxicity were identified: App6Aa2 (LC₅₀ = 49.71 μg/mL), Cry13Aa1 (LC₅₀ = 53.17 μg/mL), Cry12Aa1 (LC₅₀ = 58.88 μg/mL), Cry5Ba3 (LC₅₀ = 63.99 μg/mL), Xpp55Aa1 (LC₅₀ = 65.14 μg/mL), and Cyt8Aa1 (LC₅₀ = 96.50 μg/mL). The six toxins caused shrinkage and thinning of the intestinal cells, contraction of the intestine from the body wall, vacuolization, and degenerated appearance of the pinewood nematodes. The results of this study provide basic information to study the action mechanism of nematocidal toxins on the pinewood nematode and direction for the use of nematocidal toxins in the biological control of B. xylophilus.

Keywords: Bacillus thuringiensis; Cry toxins; Intestinal damage; Nematocidal activity; Pinewood nematode.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Antinematodal Agents / pharmacology
Bacillus thuringiensis Toxins
Pinus* / parasitology
Rhabditida*
Xylophilus

Substances

Antinematodal Agents
Bacillus thuringiensis Toxins