Phylogeny of Regulators of G-Protein Signaling Genes in Leptographium qinlingensis and Expression Levels of Three RGSs in Response to Different Terpenoids

Abstract

Leptographium qinlingensis is a bark beetle-vectored pine pathogen in the Chinese white pine beetle (Dendroctonus armandi) epidemic in Northwest China. L. qinlingensis colonizes pines despite the trees’ massive oleoresin terpenoid defenses. Regulators of G-protein signaling (RGS) proteins modulate heterotrimeric G-protein signaling negatively and play multiple roles in the growth, asexual development, and pathogenicity of fungi. In this study, we have identified three L. qinlingensis RGS genes, and the phylogenetic analysis shows the highest homology with the regulators of G-protein signaling proteins sequence from Ophiostoma piceae and Grosmannia clavigera. The expression profiles of three RGSs in the mycelium of L. qinlingensis treated with six different terpenoids were detected, as well as their growth rates. Under six terpenoid treatments, the growth and reproduction in L. qinlingensis were significantly inhibited, and the growth inflection day was delayed from 8 days to 12–13 days. By analyzing the expression level of three RGS genes of L. qinlingensis with different treatments, results indicate that LqFlbA plays a crucial role in controlling fungal growth, and both LqRax1 and LqRgsA are involved in overcoming the host chemical resistances and successful colonization.

Transcriptomic analysis of the fungus Graphilbum sp. in response to the pine wood nematode

“…Ophiostomatoid fungi are a food source for nematodes, that require the participation and regulation of multiple genes [7,33,34]. Expression of Ypt gene was upregulated in response to PWNs.…”

Establishment of RNA Interference Genetic Transformation System and Functional Analysis of FlbA Gene in Leptographium qinlingensis

“…To further validate the selected pathogenicity gene, attempts were made to standardize the RNAi-based approach during L. qinlingensis pathogenesis. Since our earlier study confirmed that FlbA plays a role in the growth and pathogenicity of L. qinlingensis [ 4 ], functional analysis of the FlbA gene has been selected for the RNAi approach using the fungal transformation vector pSilent-1 through Agrobacterium -mediated transformation (ATMT) and achieved knockdown of the target genes.…”

“…It assumes a crucial ecological and societal responsibility in water and soil conservation, thus wielding a significant impact on the local economy and ecology [ 2 ]. However, a rapid, widespread decline in Chinese white pine ( P. armandii ) has been brought on by an interaction biological complex (CWPB-Lq complex) that is formed of the Chinese white pine beetle ( Dendroctonus armandi , CWPB) and the ascomycetes fungus ( Leptographium qinlingensis , Lq) [ 3 , 4 , 5 ]. The activities of L. qinlingensis culminate in disruptions of nutrient and water metabolism, eventually leading to the demise of host trees due to the destruction of resin-producing cells and the obstruction of resin canals [ 6 ].…”

“…In Fusarium verticillioides , FvFlbA2 has a negative regulation of conidial production [ 37 ]. In our previous study, the FlbA gene played a role in the growth and pathogenicity of L. qinlingensis [ 4 ]. In light of its gene functionality and discernible phenotypic alterations, the FlbA gene was selected as the designated target for knockdown in the context of this investigation.…”

“…2023, 24, 13009 2 of 14 An et al (2022) explored the intricate connection between the TOR gene and various factors such as carbon sources, nitrogen sources, host nutrients, and host volatiles (monoterpenoids) within L. qinlingensis [15]. Gan et al (2022) reported on the role of RGS family genes in the fungal growth and development of, as well as in overcoming the host chemical resistance of, L. qinlingensis [4]. Nevertheless, the verification of gene functions and their contributions to pathogenicity necessitates the generation of mutants (or transformants) of L. qinlingensis, wherein the genes of interest are either deleted or modified.…”