In plants,RNA interference(RNAi)plays a pivotal role in growth and development,and responses to environmental inputs,including pathogen attack.The intercellular and systemic trafficking of small interfering RNA(siRNA)...In plants,RNA interference(RNAi)plays a pivotal role in growth and development,and responses to environmental inputs,including pathogen attack.The intercellular and systemic trafficking of small interfering RNA(siRNA)/microRNA(miRNA)is a central component in this regulatory pathway.Currently,little is known with regards to the molecular agents involved in the movement of these si/miRNAs.To address this situation,we employed a biochemical approach to identify and characterize a conserved SMALL RNA-BINDING PROTEIN 1(SRBP1)family that mediates non-cell-autonomous small RNA(sRNA)trafficking.In Arabidopsis,AtSRBP1 is a glycine-rich(GR)RNA-binding protein,also known as AtGRP7,which we show binds single-stranded siRNA.A viral vector,Zucchini yellow mosaic virus(ZYMV),was employed to functionally characterized the AtSRBP1-4(AtGRP7/2/4/8)RNA recognition motif and GR domains.Cellular-based studies revealed the GR domain as being necessary and sufficient for SRBP1 cell-to-cell movement.Taken together,our findings provide a foundation for future research into the mechanism and function of mobile sRNA signaling agents in plants.展开更多
基金provided by the National Science Foundation(IOS-1339128 to W.J.L.).Y.H.C.was supported,in part,by a graduate fellowship provided by the National Chung-Hsing University,Taichung,China.
文摘In plants,RNA interference(RNAi)plays a pivotal role in growth and development,and responses to environmental inputs,including pathogen attack.The intercellular and systemic trafficking of small interfering RNA(siRNA)/microRNA(miRNA)is a central component in this regulatory pathway.Currently,little is known with regards to the molecular agents involved in the movement of these si/miRNAs.To address this situation,we employed a biochemical approach to identify and characterize a conserved SMALL RNA-BINDING PROTEIN 1(SRBP1)family that mediates non-cell-autonomous small RNA(sRNA)trafficking.In Arabidopsis,AtSRBP1 is a glycine-rich(GR)RNA-binding protein,also known as AtGRP7,which we show binds single-stranded siRNA.A viral vector,Zucchini yellow mosaic virus(ZYMV),was employed to functionally characterized the AtSRBP1-4(AtGRP7/2/4/8)RNA recognition motif and GR domains.Cellular-based studies revealed the GR domain as being necessary and sufficient for SRBP1 cell-to-cell movement.Taken together,our findings provide a foundation for future research into the mechanism and function of mobile sRNA signaling agents in plants.
