The secreted GH43 protein VpGHa1 functions as an effector to suppress plant immunity and contributes to stress adaptation in Valsa pyri
Abstract
IntroductionWhile the pear canker pathogen Valsa pyri typically employs cell wall-degrading enzymes to breach host barriers, the functions of its glycoside hydrolase family 43 (GH43) proteins remain largely unexplored.MethodsHere, using genetic manipulation, secretion assays, transient-expression assays, and transcriptomic analysis, we investigated whether the GH43 protein VpGHa1 contributes to fungal virulence, stress adaptation, and suppression of host immunity.ResultsVpGHa1 contains a predicted signal peptide and a GH43_AnAbnA-like domain. VpGHa1 expression was strongly induced during the early stages of infection, and the protein was confirmed to be secreted. Sequence analysis predicted an endo-1,5-α-L-arabinofuranosidase-related function, and recombinant VpGHa1 showed positive anti-arabinase immunoreactivity in an antibody-based ELISA. Deletion of VpGHa1 reduced lesion size on pear twigs by 33.8%, whereas genetic complementation significantly restored the reduced-virulence phenotype and overexpression enhanced pathogenicity without affecting vegetative growth. The ΔVpGHa1 mutant showed increased tolerance to KCl but greater sensitivity to NaCl and H₂O₂, indicating that VpGHa1 contributes to ionic and oxidative stress adaptation. Furthermore, transient expression of VpGHa1 in Nicotiana benthamiana suppressed BAX- and INF1-induced cell death, promoted colonization by Sclerotinia sclerotiorum, and enhanced lesion formation after V. pyri challenge in apple leaves; this was accompanied by downregulation of apple defense-related genes. Transcriptomic analysis identified 115 DEGs between the WT and ΔVpGHa1 mutant and revealed enrichment of carbohydrate-related, extracellular/cell-surface-associated, and metabolic processes, suggesting broad transcriptional effects associated with cell-surface and metabolic adaptation.DiscussionTogether, these findings identify VpGHa1 as a multifunctional secreted GH43 virulence factor linking pathogenicity, stress adaptation, and host immune suppression, whereas its predicted arabinan-related enzymatic activity remains to be experimentally validated.
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BibTeX
@article{peng2026secreted,
title = {{The secreted GH43 protein VpGHa1 functions as an effector to suppress plant immunity and contributes to stress adaptation in Valsa pyri}},
author = {Shasha Peng and Zhe Wang and Hailong Liu and Zhen Zhang and Mengjie Gao and Lan Wang and Liangsheng Xu},
journal = {Frontiers in Plant Science},
year = {2026},
month = nov,
doi = {10.3389/fpls.2026.1979662},
url = {https://www.frontiersin.org/articles/10.3389/fpls.2026.1979662},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - The secreted GH43 protein VpGHa1 functions as an effector to suppress plant immunity and contributes to stress adaptation in Valsa pyri
AU - Shasha Peng
AU - Zhe Wang
AU - Hailong Liu
AU - Zhen Zhang
AU - Mengjie Gao
AU - Lan Wang
AU - Liangsheng Xu
PY - 2026
DA - 2026/11/05
JO - Frontiers in Plant Science
DO - 10.3389/fpls.2026.1979662
UR - https://www.frontiersin.org/articles/10.3389/fpls.2026.1979662
AB - IntroductionWhile the pear canker pathogen Valsa pyri typically employs cell wall-degrading enzymes to breach host barriers, the functions of its glycoside hydrolase family 43 (GH43) proteins remain largely unexplored.MethodsHere, using genetic manipulation, secretion assays, transient-expression assays, and transcriptomic analysis, we investigated whether the GH43 protein VpGHa1 contributes to fungal virulence, stress adaptation, and suppression of host immunity.ResultsVpGHa1 contains a predicted signal peptide and a GH43_AnAbnA-like domain. VpGHa1 expression was strongly induced during the early stages of infection, and the protein was confirmed to be secreted. Sequence analysis predicted an endo-1,5-α-L-arabinofuranosidase-related function, and recombinant VpGHa1 showed positive anti-arabinase immunoreactivity in an antibody-based ELISA. Deletion of VpGHa1 reduced lesion size on pear twigs by 33.8%, whereas genetic complementation significantly restored the reduced-virulence phenotype and overexpression enhanced pathogenicity without affecting vegetative growth. The ΔVpGHa1 mutant showed increased tolerance to KCl but greater sensitivity to NaCl and H₂O₂, indicating that VpGHa1 contributes to ionic and oxidative stress adaptation. Furthermore, transient expression of VpGHa1 in Nicotiana benthamiana suppressed BAX- and INF1-induced cell death, promoted colonization by Sclerotinia sclerotiorum, and enhanced lesion formation after V. pyri challenge in apple leaves; this was accompanied by downregulation of apple defense-related genes. Transcriptomic analysis identified 115 DEGs between the WT and ΔVpGHa1 mutant and revealed enrichment of carbohydrate-related, extracellular/cell-surface-associated, and metabolic processes, suggesting broad transcriptional effects associated with cell-surface and metabolic adaptation.DiscussionTogether, these findings identify VpGHa1 as a multifunctional secreted GH43 virulence factor linking pathogenicity, stress adaptation, and host immune suppression, whereas its predicted arabinan-related enzymatic activity remains to be experimentally validated.
SN - 1664-462X
ER -