Arabidopsis PDLP7 modulated plasmodesmata function is related to BG10-dependent glucosidase activity required for callose degradation  

拟南芥PDLP7介导葡聚糖苷酶调控胞间连丝功能研究

作　　者：Xin Chen Wan-Wan Li Jin Gao Zhiguo Wu Juan Du Xiaoming Zhang Yu-Xian Zhu 陈欣;李弯弯;高晋;吴志国;杜鹃;张晓明;朱玉贤

机构地区：[1]State Key Laboratory of Protein and Plant Gene Research,College of Life Sciences,Peking University,Beijing 100871,China [2]State Key Laboratory of Integrated Management of Pest Insects and Rodents,Institute of Zoology,Chinese Academy of Sciences,Beijing 100101,China [3]Institute for Advanced Studies,Wuhan University,Wuhan 430072,China

出　　处：《Science Bulletin》2024年第19期3075-3088,共14页科学通报（英文版）

基　　金：supported by the National Natural Science Foundation of China(31830057)。

摘　　要：The microdomains of plasmodesmata,specialized cell-wall channels responsible for communications between neighboring cells,are composed of various plasmodesmata-located proteins(PDLPs)and lipids.Here,we found that,among all PDLP or homologous proteins in Arabidopsis thaliana genome,PDLP5 and PDLP7 possessed a C-terminal sphingolipid-binding motif,with the latter being the only member that was significantly upregulated upon turnip mosaic virus and cucumber mosaic virus infections.pdlp7mutant plants exhibited significantly reduced callose deposition,larger plasmodesmata diameters,and faster viral transmission.These plants exhibited increased glucosidase activity but no change in callose synthase activity.PDLP7 interacted specifically with glucan endo-1,3-β-glucosidase 10(BG10).Consistently,higher levels of callose deposition and slower virus transmission in bg10 mutants were observed.The interaction between PDLP7 and BG10 was found to depend on the presence of the Gnk2-homologous 1(Gn K2-1)domain at the N terminus of PDLP7 with Asp-35,Cys-42,Gln-44,and Leu-116 being essential.In vitro supplementation of callose was able to change the conformation of the Gn K2-1 domain.Our data suggest that the Gn K2-1 domain of PDLP7,in conjunction with callose and BG10,plays a key role in plasmodesmata opening and closure,which is necessary for intercellular movement of various molecules.

关 键 词：PLASMODESMATA PDLP7 CALLOSE β-1 3-glucosidase 

分 类 号：Q945[生物学—植物学]