枣植原体分泌蛋白ncSP35抑制超敏反应及植物生长发育

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中图分类号：S665.1；Q945.8 文献标志码：A 文章编号：1008-0864（2025）11-0164-10

Abstract：Jujube witches’broom（JWB），caused by Candidatus Phytoplasma ziziphi，is currently the most devastating jujube disease.A novel non-classcal secretory protein，ncSP35，was identified from the JWB phytoplasma through bioinformatics analysis combined with an Escherichia coli-based alkalinephosphatase reporter system. Transient expression of ncSP35 in Nicotiana benthamiana using a potato virus X-based expression vector demonstrated that the protein suppressed Bax-triggered hypersensitive response（HR）and hydrogen peroxide accumulation，and interfered with plant growth and development.Deletion and site-directed mutagenesis analysesrevealed that the central region （amino acid residues 37～71）and the polar amino acid cluster HKKENK 82 of ncSP35 were critical for HR suppression，while the C-terminal 18 amino acid residues were essential for interfering with plant growth and development.Subcellular localizationanalysis showed that ncSP35 formed abundant aggregates in the cytoplasm and inhibited the nuclear localization of histone H2B， causing H2B to also form aggregates in the cytoplasm.Yeast two-hybrid，co-immunoprecipitation and luciferase complementation assays confirmed the specific interaction between ncSP35 and jujube ZjH2B.Above results provided new molecular insights for JWB pathogenesis.

Keywords：candidatus phytoplasma ziziphi； non-classical secretory protein；hypersensitive response；plant growth and development;histone 2B；protein-protein interaction

病原菌在与植物互作过程中常产生一系列分泌蛋白，即效应因子。（剩余17557字）