中国农业科学2026，Vol.59Issue(1)：90-100,11.DOI:10.3864/j.issn.0578-1752.2026.01.007
光合作用系统Ⅱ相关蛋白NbPsbQ1通过促进光合效率抑制病毒侵染
The Photosystem Ⅱ Protein NbPsbQ1 Inhibits Viral Infection by Promoting Photosynthetic Efficiency
摘要
Abstract
[Background]Cucumber green mottle mosaic virus(CGMMV)is one of the important quarantined plant viruses in China.It mainly infects Cucurbitaceae crops,causing severe yield losses of Cucurbitaceae crops worldwide.The PsbQ protein(oxygen-evolving enhancer protein 3)is one of the proteins associated with the photosystem Ⅱ(PSII)oxygen-evolving complex(OEC).It is involved in PSII assembly,stabilizes PSII function,and regulates plant responses to biotic and abiotic stresses.Previous studies have shown that CGMMV infection can significantly downregulate the expression of the host chloroplast regulatory gene NbPsbQ1.[Objective]This study aims to clarify the mechanism by which NbPsbQ1 participates in CGMMV infection and provide a theoretical basis for the prevention and control of CGMMV infection.[Method]The expression vector of NbPsbQ1-GFP and CGMMV CP was constructed,transformed into Agrobacterium GV3101 and infiltrated the tobacco leaves to observe the subcellular localization of NbPsbQ1 by confocal microscopy.qRT-PCR was used to analyze the transcriptional levels of NbPsbQ1 at different stages of CGMMV infection and after CP overexpression.The interaction between NbPsbQ1 and CP in vivo and in vitro was verified using bimolecular fluorescence complementation(BiFC),co-immunoprecipitation(Co-IP),and yeast two-hybrid(Y2H)assays,respectively.TRV-mediated gene silencing(VIGS)was employed to investigate the role of NbPsbQ1 during CGMMV infection.Transient overexpression of NbPsbQ1 was used to further verify the effect of NbPsbQ1 on the protein level and transcriptional level of CGMMV.The photosynthetic efficiency indicators of plants were determined after NbPsbQ1 silencing and at different stages of CGMMV infection,the effects of NbPsbQ1 and CGMMV on plant photosynthesis were analyzed.[Result]Subcellular localization results showed that NbPsbQ1 was localized in chloroplasts,while CP was localized in the cytoplasm and nucleus.After CGMMV infection or CP overexpression,the transcriptional level of NbPsbQ1 was significantly downregulated compared with the control.Results from both BiFC and Co-IP assays demonstrated that NbPsbQ1 interacts with CP in vivo.Furthermore,this interaction causes the subcellular localization of NbPsbQ1 to shift from chloroplasts to the cytoplasm.However,the yeast two-hybrid(Y2H)assay confirmed that the two proteins do not interact in vitro.CGMMV was inoculated into TRV:NbPsbQ1 and TRV:00 plants.Partial systemic leaves of plants in both the TRV:NbPsbQ1 and TRV:00 plants began to show mottling and curling symptoms at 4 dpi.However,the number of symptomatic plants was consistently higher in the TRV:NbPsbQ1 plants than that in the control plants.Meanwhile,detection of mRNA and protein expression levels also indicated that silencing NbPsbQ1 effectively promoted CGMMV accumulation.Transient overexpression of NbPsbQ1 inhibited the accumulation of CP,further confirming that NbPsbQ1 suppresses CGMMV infection.Silencing of NbPsbQ1 significantly reduced the net photosynthetic rate(Pn),stomatal conductance(Gs),and transpiration rate(Tr)of plant leaves,while the intercellular CO2 concentration(Ci)increased significantly,indicating that NbPsbQ1 is involved in plant photosynthesis.Additionally,it was found that Gs and Tr decreased significantly,while Ci increased at 9 d during CGMMV infection.[Conclusion]The CP of CGMMV interacts with NbPsbQ1 in vivo and alters its chloroplast localization.During the CGMMV infection,the expression level of NbPsbQ1 is downregulated,and photosynthetic efficiency is inhibited,thereby promoting the CGMMV accumulation in the late infection stage.关键词
黄瓜绿斑驳花叶病毒/NbPsbQ1/光合作用系统II/光合作用/致病机制Key words
cucumber green mottle mosaic virus(CGMMV)/NbPsbQ1/photosystem II(PSII)/photosynthesis/pathogenic mechanism引用本文复制引用
付涵,杨雪,于杨,艾妞,张思晴,于连伟,孙书豪,赵金章,韩晓玉,施艳..光合作用系统Ⅱ相关蛋白NbPsbQ1通过促进光合效率抑制病毒侵染[J].中国农业科学,2026,59(1):90-100,11.基金项目
河南省高校科技创新团队(25IRTSTHN031)、中原青年拔尖人才项目(30603407) （25IRTSTHN031）
