Bx-daf-22 Contributes to Mate Attraction in the Gonochoristic Nematode Bursaphelenchus xylophilus

Abstract

Studying sex communication is necessary to develop new methods to control the population expansion of gonochoristic species Bursaphelenchus xylophilus, the pathogen of pine wilt disease (PWD). Small chemical signals called ascarosides have been reported to attract potential mates. However, they have not been studied in the sex attraction of B. xylophilus. Here, we confirmed the sex attraction of B. xylophilus using a chemotaxis assay. Then, we cloned the downstream ascaroside biosynthetic gene Bx-daf-22 and explored its function in the sex attraction of B. xylophilus through bioinformatics analysis and RNA interference. The secretions of females and males were the sources of sex attraction in B. xylophilus, and the attractiveness of females to males was stronger than that of males to females. Compared with daf-22 of Caenorhabditis elegans, Bx-daf-22 underwent gene duplication events, resulting in Bx-daf-22.1, Bx-daf-22.2, and Bx-daf-22.3. RNA interference revealed that the attractiveness of female secretions to males increased after all three Bx-daf-22 genes or Bx-daf-22.3 had been interfered. However, the reciprocal experiments had no effect on the attractiveness of male secretions to females. Thus, Bx-daf-22 genes, especially Bx-daf-22.3, may be crucial for the effectiveness of female sex attractants. Our studies provide fundamental information to help identify the specific components and signal pathways of sex attractants in B. xylophilus.

Cinnamyl Alcohol Dehydrogenase Gene Regulates Bursaphelenchus xylophilus Reproduction and Development

“…In contrast, PWNs of RNAi for BxCAD-1 did not show obvious massive aggregation behavior, and there was no significant change in behavior even after providing 1% ethanol. Small chemical signals, such as ascarosides with hydroxyls, have been reported to attract potential mates of B. xylophilus [70]. Considering that cinnamyl alcohol dehydrogenase could catalyze the reaction of various substrates containing hydroxyls such as D-pinitol, sorbitol and 2-methoxyphenol, we speculated that B. xylophilus might be stimulated to mate by hydroxyl-oxidated aldehyde group-containing substances catalyzed by BxCAD-1.…”

Effect of Associated Bacteria GD1 on the Low-Temperature Adaptability of Bursaphelenchus xylophilus Based on RNA-Seq and RNAi

“…This phenomenon is called RNAi [ 34 ]. In recent years, RNAi technology has been frequently used to assess PWN gene function, such as identifying the role of cathepsin L-like cysteine protease in PWN reproduction and pathogenicity [ 35 ], the role of Bx-daf-22 in PWN mate attraction [ 36 ] and the role of daf-16-2b in PWN detoxification metabolism processes [ 37 ]. RNAi technology has also played an important role in the study of the low-temperature adaptation mechanism of PWNs.…”

Molecular Characterization and Functional Analysis of GPCR Gene Bx-srh-1 in Pinewood Nematode (Bursaphelenchus xylophilus)

“…In China, this disease was first identified in Nanjing City, Jiangsu Province, in 1982 and has since spread rapidly to 19 provinces, encompassing 731 county administrative regions and covering an area of 650,000 ha [10][11][12]. Despite extensive research on the pathogenicity, biological properties, infection cycle, and vector insects [13][14][15][16][17], the high mortality rate of host trees and the rapid spread of the disease continue to pose a significant challenge.…”