Abstract
Abstract
Background
Pine trees challenged by Bursaphelenchus xylophilus invasion produce phytoalexins to combat this nematode. Nevertheless, the phytoalexins of Asian pine trees are ineffective against B. xylophilus. The anti-phytoalexin genes of B. xylophilus disable almost all Asian pine phytoalexins, which has allowed B. xylophilus to devastate pine forests in eastern Asia over the last four decades. However, to date, the factors that stimulate anti-phytoalexin gene expression and the mechanisms by which these genes act are not well understood.
Results
Here, we described anti-phytoalexin genes in B. xylophilus using transcriptomic and bioinformatics analyses. The genes that were induced by both Pinus massoniana and carvone and had similarly elevated expression trends were considered anti-phytoalexin genes. Altogether, 187 anti-phytoalexin genes were identified, including 4 cathepsin genes. KEGG pathway enrichment indicated that those cathepsins were related to the Lysosome pathway. Since cathepsins help to maintain metabolic homeostasis by participating in the degradation of heterophagic and autophagic material, the lysosomal cathepsin gene Bx-cathepsin W was cloned and characterized. The results of the RNAi assessment indicated that the knockdown of Bx-cathepsin W reduced the survival rates of B. xylophilus under carvone or P. massoniana stress. The correlation between Bx-cathepsin W and the susceptibility of pines showed that Bx-cathepsin W might help improve the anti-phytotoxin ability of B. xylophilus.
Conclusions
The results indicated that the anti-phytoalexin gene Bx-cathepsin W supported the survival of B. xylophilus under P. massoniana phytoalexin stress. The cDNA library sequencing, differentially expressed gene identification, and WGCNA algorithm analysis provided insight at a systemic level into the gene regulation of B. xylophilus in response to the immune reaction of P. massoniana. These results will lead to a better understanding of the function of nematode defenses in host innate immunity.
Funder
National Key R & D Program of China
National Natural Science Foundation of China
Fundamental Research Funds for the Central Universities
Publisher
Springer Science and Business Media LLC
Reference37 articles.
1. Jones JT, Moens M, Mota M, Li H, Kikuchi T. Bursaphelenchus xylophilus: opportunities in comparative genomics and molecular host-parasite interactions. Mol Plant Pathol. 2008;9(3):357–68.
2. Mota MBH, Bravo M, Penas A, Burgermeister W. First report of Bursaphelenchus xylophilus in Portugal and in Europe. Nematology. 1999;17:8.
3. Wang F, Wang Z, Li D, Chen Q. Identification and characterization of a Bursaphelenchus xylophilus (Aphelenchida: Aphelenchoididae) thermotolerance-related gene: Bx-HSP90. Int J Mol Sci. 2012;13(7):8819–33.
4. Lapin D, Van den Ackerveken G. Susceptibility to plant disease: more than a failure of host immunity. Trends Plant Sci. 2013;18(10):546–54.
5. Hammerschmidt R. PHYTOALEXINS: what have we learned after 60 years? Annu Rev Ohytopathol. 1999;37:22.
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