[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-seo-455677-105":3,"detail-sidebar-cat-0-en-105":81,"doc-detail-455677-en":130},{"code":4,"msg":5,"data":6},0,"ok",{"site_id":7,"language":8,"slug":9,"title":10,"keywords":11,"description":12,"schema_data":13,"social_meta":74,"head_meta":76,"extra_data":78,"updated_unix":80},105,"en","defence-mediated-phloem-restriction-of-a-plant-virus-facilitates-insect-transmission","Defence-mediated phloem restriction of a plant virus facilitates insect transmission","","Plant viruses drive devastating crop diseases and threaten food security, especially those transmitted by phloem-feeding insects. Many such viruses remain restricted to the phloem after transmission, yet the molecular basis of this tissue tropism and its impact on the viral life cycle have been unclear. This study shows that tobacco curly shoot virus phloem restriction depends on the C4 allele, controlling PEN3 stability, callose deposition, and whether viral escape enables more efficient insect acquisition and transmission.",{"@graph":14,"@context":73},[15,34,56],{"@type":16,"itemListElement":17},"BreadcrumbList",[18,23,27,31],{"item":19,"name":20,"@type":21,"position":22},"https://docshare.wps.com","Home","ListItem",1,{"item":24,"name":25,"@type":21,"position":26},"https://docshare.wps.com/document/","Document",2,{"item":28,"name":29,"@type":21,"position":30},"https://docshare.wps.com/document/research-report/","Research & Report",3,{"item":32,"name":10,"@type":21,"position":33},"https://docshare.wps.com/document/defence-mediated-phloem-restriction-of-a-plant-virus-facilitates-insect-transmission/455677/",4,{"url":32,"name":10,"@type":35,"image":36,"author":41,"headline":10,"publisher":44,"fileFormat":47,"inLanguage":8,"description":12,"dateModified":48,"datePublished":49,"encodingFormat":47,"isAccessibleForFree":50,"interactionStatistic":51},"DigitalDocument",{"url":37,"@type":38,"width":39,"height":40},"https://docshare.wps.com/thumbnails/defence-mediated-phloem-restriction-of-a-plant-virus-facilitates-insect-transmission/455677.png","ImageObject",300,407,{"name":42,"@type":43},"Miles","Person",{"url":19,"name":45,"@type":46},"DocShare","Organization","application/pdf","2026-10-08","2026-09-30",true,{"@type":52,"interactionType":53,"userInteractionCount":55},"InteractionCounter",{"@type":54},"ViewAction",5,{"@type":57,"mainEntity":58},"FAQPage",[59,65,69],{"name":60,"@type":61,"acceptedAnswer":62},"What determines whether tobacco curly shoot virus is restricted to the phloem?","Question",{"text":63,"@type":64},"Phloem restriction depends on the C4 allele the virus carries. The Y35 allele produces a plasma membrane-associated C4 protein and is phloem-limited, while Y41 produces variants targeting the plasma membrane and chloroplasts that compromise restriction.","Answer",{"name":66,"@type":61,"acceptedAnswer":67},"How does chloroplast-localized C4 from TbCSV(Y41) affect plant defenses?",{"text":68,"@type":64},"Chloroplast-localized C4 interferes with salicylic acid-mediated defenses, destabilizes PEN3, decreases callose deposition, and allows the virus to escape from the phloem to surrounding parenchyma cells.",{"name":70,"@type":61,"acceptedAnswer":71},"Why does phloem restriction benefit viral spread by insect vectors?",{"text":72,"@type":64},"The study finds that phloem restriction favors acquisition and transmission by the insect vector, giving TbCSV(Y35) a competitive advantage, and it also indicates PEN3 activity can determine phloem restriction for an RNA virus.","https://schema.org",{"og:url":32,"og:type":75,"og:title":10,"og:site_name":45,"og:description":12},"article",{"robots":77,"canonical":32},"index,follow",{"doc_id":79,"site_id":7},455677,1790815374,{"code":4,"msg":82,"data":83},"success",[84,88,92,96,100,105,110,114,119,122,126],{"id":22,"doc_module":4,"doc_module_name":25,"category_name":85,"show_sort_weight":86,"slug":87},"Story & Novel",90,"story-novel",{"id":26,"doc_module":4,"doc_module_name":25,"category_name":89,"show_sort_weight":90,"slug":91},"Literature",80,"literature",{"id":33,"doc_module":4,"doc_module_name":25,"category_name":93,"show_sort_weight":94,"slug":95},"Exam",70,"exam",{"id":55,"doc_module":4,"doc_module_name":25,"category_name":97,"show_sort_weight":98,"slug":99},"Comic",60,"comic",{"id":101,"doc_module":4,"doc_module_name":25,"category_name":102,"show_sort_weight":103,"slug":104},6,"Technology",50,"technology",{"id":106,"doc_module":4,"doc_module_name":25,"category_name":107,"show_sort_weight":108,"slug":109},7,"Healthcare",40,"healthcare",{"id":111,"doc_module":4,"doc_module_name":25,"category_name":29,"show_sort_weight":112,"slug":113},8,30,"research-report",{"id":115,"doc_module":4,"doc_module_name":25,"category_name":116,"show_sort_weight":117,"slug":118},9,"Religion & Spirituality",20,"religion-spirituality",{"id":117,"doc_module":4,"doc_module_name":25,"category_name":120,"show_sort_weight":117,"slug":121},"World Cup","world-cup",{"id":123,"doc_module":4,"doc_module_name":25,"category_name":124,"show_sort_weight":123,"slug":125},10,"Lifestyle","lifestyle",{"id":127,"doc_module":4,"doc_module_name":25,"category_name":128,"show_sort_weight":55,"slug":129},19,"General","general",{"code":4,"msg":82,"data":131},{"doc_id":79,"user_id":132,"nickname":42,"user_avatar":133,"doc_module":4,"category_id":111,"category_name":29,"doc_title":10,"doc_description":12,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":55,"is_deleted":4,"is_public":22,"is_downloadable":22,"audit_status":22,"page_count":139,"language":140,"language_code":8,"site_id":7,"html_lang":8,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":12,"update_tm":144,"read_time":145},13056703019404,"https://ap-avatar.wpscdn.com/davatar_29158cc5080c5b710cf443261637dec0","Article [https://doi.org/10.1038/s41467-025-67827-w](https://doi.org/10.1038/s41467-025-67827-w)  \nDefence-mediated phloem restriction of a plant virus facilitates insect transmission  \nReceived: 29 April 2025  \n\n| Accepted: 10 December 2025 |\n| --- |\n| |\n| Check for updates |\n\nYuzhen Mei1,2, Yaqin Wang2, Fangfang Li1, Rosa Lozano-Durán 3  & Xueping Zhou 1,2   \nPlant viruses are causal agents of devastating diseases in crops and pose a threat to food security. Viruses transmitted by phloem-feeding insects are frequently restricted to the phloem; the mechanism determining this tissue tropism and its consequences for the viral cycle have remained elusive. Here we show that phloem restriction of tobacco curly shoot virus (TbCSV)depends on the allele of the C4 gene it carries. The Y35 allele produces a plasma membrane-associated C4 protein; TbCSV(Y35) is phloem-limited. The Y41 allele, however, produces two C4 variants, targeted to the plasma membrane and chloroplasts, respectively. Chloroplast-localized C4 interferes with salicylic acid-mediated defenses, which causes a destabilization of PENETRATION3 (PEN3), a subsequent decrease in callose deposition, and the escape of TbCSV(Y41) to the surrounding parenchyma cells. Interestingly, Y41 expands the host range of TbCSV, but Y35 is prevalent in nature. We determine that phloem restriction favors acquisition and transmission by the insect vector, conferring a competitive advantage to TbCSV(Y35). Importantly, PEN3 also determines phloem restriction of an RNA virus. In summary, we demonstrate that PEN3 activity and likely callose deposition confine viruses to the phloem, which favors viral spread by facilitating acquisition by the insect vector.  \nPlant viruses cause devastating diseases in crops worldwide, posing a serious threat to global food security. Most plant viruses are transmitted by phloem-feeding insects; following transmission by the vector, many viruses remain restricted to the phloem1–4. Despite the prevalence of this tissue tropism, the underlying molecular mechanisms as well as its significance for viral performance have so far remained elusive.  \nInsect-transmitted viruses from the Geminiviridae family are causal agents of economically relevant diseases affecting cash and staple crops in tropical and temperate regions of the world. Most geminiviruses are transmitted by the phloem-feeding whitefly Bemisiatabaci, and most of these are phloem-limited. Many species within this family encode a protein named C4, which is versatile and essential for full infectivity, suppressing plant anti-viral defenses and mediating  \nsymptom development5–7. C4 proteins from different geminiviruses possess different combinations of targeting signals and show specific subcellular localizations6; the C4 protein encoded by tomato yellow leaf curl virus (TYLCV), for example, displays a dual localization at the plasma membrane and in chloroplasts, moving from the former to the latter during infection8. At the plasma membrane, C4 from TYLCV suppresses the cell-to-cell spread of silencing, while in chloroplasts it interferes with the activation of anti-viral salicylic acid (SA)-dependent defenses8,9. This subcellular compartmentalization that enables multifunctionality of C4 seems to be relevant for the infection, as geminiviruses have evolved independent strategies to accomplish it. Recently, it has been demonstrated that some geminiviruses encode two variants of the C4 protein in their C4 gene, differing in the two N-terminal residues only, resulting from translation initiation from two  \n1State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China. 2State Key Laboratory of Rice Biology and Breeding, Institute of Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China. 3Department of Plant Biochemistry, Centre for Plant Molecular Biology (ZMBP), Eberhard Karls University, D-72076, Tübingen, German","cbCaigeq0kj2Ddd1","https://ap.wps.com/l/cbCaigeq0kj2Ddd1","pdf",20491611,14,"English","# Abstract\n# Results\n## TbCSV (Y41) isolates have a lower epidemic rate\n# Mechanistic model and implications\n## C4 allele-dependent phloem limitation and PEN3 activity","[{\"question\":\"What determines whether tobacco curly shoot virus is restricted to the phloem?\",\"answer\":\"Phloem restriction depends on the C4 allele the virus carries. The Y35 allele produces a plasma membrane-associated C4 protein and is phloem-limited, while Y41 produces variants targeting the plasma membrane and chloroplasts that compromise restriction.\"},{\"question\":\"How does chloroplast-localized C4 from TbCSV(Y41) affect plant defenses?\",\"answer\":\"Chloroplast-localized C4 interferes with salicylic acid-mediated defenses, destabilizes PEN3, decreases callose deposition, and allows the virus to escape from the phloem to surrounding parenchyma cells.\"},{\"question\":\"Why does phloem restriction benefit viral spread by insect vectors?\",\"answer\":\"The study finds that phloem restriction favors acquisition and transmission by the insect vector, giving TbCSV(Y35) a competitive advantage, and it also indicates PEN3 activity can determine phloem restriction for an RNA virus.\"}]","Defence-mediated phloem restriction of a plant virus facilitates insect transmission | PDF",1790743858,35]