Arabidopsis SYP71/72/73 Functional Analysis On Vesicle Trafficking And Plant Growth And Development

Vesicle trafficking includes four steps:budding,movement,tethering and fusion.These steps are regulated by many factors,such as coat,SM,tether,SNARE,and Rab proteins.SNARE proteins play an essential role on fusion.The formation of the SNARE complex mediates membrane fusion.By bioinformatics prediction,in Arabidopsis thaliana,AtUsel is the homologou of yeast Usel.AtUsel and AtUfel(SYP81)might form a SNARE complex,and play a role in Golgi-ER vesicle transport.In this study,we further explored the function of the AtUsel candidate gene,SYP7 family,including SYP71/72/73.We analyzed tissue specific expression of SYP71/72/73 by qPCR and Western blot.We checked the RNA expression level of SYP71 in syp71-1,overexpression lines p35S::myc-SYP71 and SYP7RNAi transgenic lines by Northern blot,.Through transient expression,we observed that SYP72 and SYP73 are localized on ER in A.thaliana suspension cells.At the same time,We observed the phenotypes of the mutants and transgenic plants:syp71-1,syp72-1,syp72-2,syp73-1,syp73-2,over-expression lines of p35S::myc-SYP71,p35S::myc-SYP73,p35S::myc-SYP73 and SYP7RNAi transgenic plants.The results indicate that,when SYP71 is down-regulated,root growth is affected during early development stage.When SYP72 is down-regulated,root grow better.Interaction between SYP7 and SYP81 were detected by pulldown analysis.Above results indicate that,in Arabidopsis plant cells,Qc-SNARE SYP71/72/72 interact with Qa-SNARE SYP81,regulate Golgi-ER vesicle transport,and plant development.