Expression of the Thaumatin-Like Protein-1 Gene (Bx-tlp-1) from Pine Wood Nematode Bursaphelenchus xylophilus Affects Terpene Metabolism in Pine Trees

Abstract

Pine wilt disease is a major forest disease worldwide, including in China, where it has severely damaged pine forest ecosystems, and the pathogen is pine wood nematode (Bursaphelenchus xylophilus). The thaumatin-like protein-1 gene (Bx-tlp-1) is a key gene associated with B. xylophilus pathogenicity, which is also responsive to α-pinene. In this study, an examination of Pinus massoniana seedlings infected by B. xylophilus revealed that monoterpene (sesquiterpene) levels peaked on days 15 and 27 (days 18 and 27). Meanwhile, P. massoniana Pm-tlp expression levels were high on days 3, 12, and 27, which were consistent with the expression of key enzymes genes in the terpene biosynthesis pathway. The functional similarity of B. xylophilus Bx-TLP-1 and P. massoniana Pm-TLP suggests Bx-TLP-1 and Pm-TLP may have similar roles in P. massoniana. There was also no secondary accumulation of terpenes in P. massoniana seedlings during B. xylophilus treated with dsRNA targeting Bx-tlp-1 (dsTLP1) infections, reflecting the decreased pathogenicity of B. xylophilus and the delayed disease progression in pine trees. And the results of micro-CT showed that the degree of cavitation for the trees inoculated with Bx-TLP-1 (0.3811 mm3) was greater than that for the trees inoculated with dsTLP1 PWNs (0.1204 mm3) on day 15 after inoculation. Results from this study indicated that B. xylophilus Bx-tlp-1 gene may induce the upregulated expression of related genes encoding enzymes in the terpene synthesis pathway of P. massoniana, resulting in the accumulation of terpenes, which also provided an insight to investigate the B. xylophilus pathogenicity in the future.

Genes Encoding Potential Molecular Mimicry Proteins as the Specific Targets for Detecting Bursaphelenchus xylophilus in PCR and Loop-Mediated Isothermal Amplification Assays

“…Researchers identified substances released by pathogens that mimic plant defense-related compounds and disrupt physiologically important plant signaling pathways ( Winn et al, 2021 ). Previous studies revealed the relatively high similarity between the Bx-TLP (Bx-CPI) and Pm-TLP (Pm-CPI) sequences, indicative of a similarity in their functions ( Wang et al, 2014 ; Meng et al, 2017 , 2020 , 2022 ). Moreover, the expression of B. xylophilus genes encoding potential molecular mimicry proteins ( Bx-tlp-1 , Bx-tlp-2 , and Bx-cpi ) is responsive to α-pinene, which may affect terpene metabolism in pine trees and influence the pathogenicity of B. xylophilus ( Meng et al, 2019 , 2020 , 2022 ).…”

Global Occurrence of Pine Wilt Disease: Biological Interactions and Integrated Management

“…Researchers identified substances released by pathogens that mimic plant defense-related compounds and disrupt physiologically important plant signaling pathways (Winn et al, 2021). Previous studies revealed the relatively high similarity between the Bx-TLP (Bx-CPI) and Pm-TLP (Pm-CPI) sequences, indicative of a similarity in their functions (Wang et al, 2014;Meng et al, 2017Meng et al, , 2022. Moreover, the expression of B. xylophilus genes encoding potential molecular mimicry proteins (Bx-tlp-1, Bx-tlp-2, and Bx-cpi) is responsive to α-pinene, which may affect terpene metabolism in pine trees and influence the pathogenicity of B. xylophilus (Meng et al, 2019(Meng et al, , 2022.…”

Ciências Agrárias: limites e potencialidades em pesquisa

“…A família das PR-5, classificadas em Thaumatinas (TLPs) são proteínas universais em plantas, incluindo o grupo das angiospermas, gimnospermas e briófitas (LIU et al, 2010a), todavia, vale ressaltar que essas proteínas são encontradas em fungos (LIU et al, 2020), insetos (NOH; JO, 2016), nematoides (MENG et al, 2022), ou até mesmo em mamíferos (YAMAMOTO et al, 2020).…”