Geminiviruses cause substantial crop yield losses worldwide. The replication initiator protein (Rep) encoded by geminiviruses is indispensable for geminiviral replication. The Rep protein encoded by beet severe curly top virus (BSCTV, genus Curtovirus, family Geminiviridae) induces VARIANT IN METHYLATION 5 (VIM5) expression in Arabidopsis leaves upon BSCTV infection. VIM5 functions as a ubiquitination-related E3 ligase to promote the proteasomal degradation of methyltransferases, resulting in reduction of methylation levels in the BSCTV C2-3 promoter. However, the specific domains of Rep responsible for VIM5 induction remain poorly characterized. Although Rep proteins from several geminiviruses act as viral suppressors of RNA silencing (VSRs), whether BSCTV Rep also possesses VSR activity remains to be illustrated. In this study, we employed a transient expression system in the 16c-GFP transgenic and the wild-type Nicotiana benthamiana plants to analyze the VSR and the VIM5-inducing activities of different truncated Rep proteins haboring distinct domains. We found that the N-terminal domain (amino acids 1-180) of Rep suppressed GFP silencing in 16c-GFP transgenic N. benthamiana leaves. The minimal N-terminal fragment (amino acids 1-104) induced VIM5 expression upon co-infiltration, while C-terminal truncations lacked VIM5-inducing activity. Our results indicate that the N-terminal domain of Rep encoded by BSCTV mediates the suppression of RNA silencing and induces VIM5 expression. Thus, our findings contribute to a better understanding of interactions between geminiviral Rep and plant hosts.
Geminiviridae/genetics* ; Nicotiana/metabolism* ; Arabidopsis/metabolism* ; RNA Interference ; Viral Proteins/metabolism* ; Arabidopsis Proteins/metabolism* ; Plants, Genetically Modified/metabolism* ; Protein Domains ; Plant Diseases/virology* ; Methyltransferases/metabolism* ; Ubiquitin-Protein Ligases/metabolism* ; DNA Helicases/genetics*

Objective To study the effect of Chinese wild rice diet on lipid metabolism in rats. Method Forty four male SD rats were divided into 4 groups:control group, high lipid group, white rice-flour group and Chinese wild rice group. All groups were given different experimental diets for 8 w and body weights, serum TC, TG, HDL-C, high sensitive C-reactive protein (hs-CRP), TNF-? and IL-6 were measured. Results The hyperlipidemic rat model was successfully induced. When compared with high lipid group and white rice-flour diet group, serum TG and TC contents were significantly decreased, and HDL-C significantly increased in the Chinese wild rice group. Moreover, Chinese wild rice group had lower contents of serum hs-CRP and TNF-? than those in high lipid group and white rice-flour group, but no effect on serum IL-6. Conclusion Chinese wild rice could improve lipid metabolism and low-grade inflammation of hyperlipidemic rats induced by high lipid diet.