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OsRDR6 plays role in host defense against double-stranded RNA virus, Rice Dwarf Phytoreovirus.

Hong W, Qian D, Sun R, Jiang L, Wang Y, Wei C, Zhang Z, Li Y - Sci Rep (2015)

Bottom Line: We found previously that rice RDR6 (OsRDR6) functioned in the defense against Rice stripe virus (RSV), and Rice Dwarf Phytoreovirus (RDV) infection resulted in down-regulation of expression of RDR6.Our result showed that down-regulation of OsRDR6 through the antisense (OsRDR6AS) strategy increased rice susceptibility to RDV infection while over-expression of OsRDR6 had no effect on RDV infection.The accumulation of RDV vsiRNAs was reduced in the OsRDR6AS plants.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China.

ABSTRACT
RNAi is a major antiviral defense response in plant and animal model systems. RNA-dependent RNA polymerase 6 (RDR6) is an essential component of RNAi, which plays an important role in the resistance against viruses in the model plants. We found previously that rice RDR6 (OsRDR6) functioned in the defense against Rice stripe virus (RSV), and Rice Dwarf Phytoreovirus (RDV) infection resulted in down-regulation of expression of RDR6. Here we report our new findings on the function of OsRDR6 against RDV. Our result showed that down-regulation of OsRDR6 through the antisense (OsRDR6AS) strategy increased rice susceptibility to RDV infection while over-expression of OsRDR6 had no effect on RDV infection. The accumulation of RDV vsiRNAs was reduced in the OsRDR6AS plants. In the OsRDR6 over-expressed plants, the levels of OsRDR6 RNA transcript and protein were much higher than that in the control plants. Interestingly, the accumulation level of OsRDR6 protein became undetectable after RDV infection. This finding indicated that the translation and/or stability of OsRDR6 protein were negatively impacted upon RDV infection. This new finding provides a new light on the function of RDR6 in plant defense response and the cross-talking between factors encoded by host plant and double-stranded RNA viruses.

No MeSH data available.


Related in: MedlinePlus

RDV infection reduced the expression of OsRDR6 in the OsRDR6-over-expression rice plants.(a) Relative expression levels of OsRDR6 RNA transcript in the OsRDR6 OE, EV and WT plants. Relative transcript levels were calculated using the 2−ΔΔC(t) method and OsEF-1a gene transcripts as the internal control. The error bars indicate the standard errors. Asterisks indicate P values compared with healthy rice plants: * P < 0.05; ** P < 0.01 (Student’s t test). (b) Western blot assay of OsRDR6 proteins accumulation in OsRDR6 OE, EV and WT plants. Expression of rice Hsp90 protein was used as the loading control.
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f4: RDV infection reduced the expression of OsRDR6 in the OsRDR6-over-expression rice plants.(a) Relative expression levels of OsRDR6 RNA transcript in the OsRDR6 OE, EV and WT plants. Relative transcript levels were calculated using the 2−ΔΔC(t) method and OsEF-1a gene transcripts as the internal control. The error bars indicate the standard errors. Asterisks indicate P values compared with healthy rice plants: * P < 0.05; ** P < 0.01 (Student’s t test). (b) Western blot assay of OsRDR6 proteins accumulation in OsRDR6 OE, EV and WT plants. Expression of rice Hsp90 protein was used as the loading control.

Mentions: To investigate the effect of RDV infection on OsRDR6 expression in rice plants, we analyzed OsRDR6 mRNA and protein accumulation in the RDV-inoculated and non-inoculated OsRDR6 OE, EV and WT rice plants through quantitative RT-PCR. Results of the assay showed that the levels of OsRDR6 mRNA were much higher in the OE plants than those in the WT or EV control plants (Fig. 4a). Interestingly, RDV infection resulted in decreased levels of OsRDR6 transcripts in all assayed plants. Western blot assay agreed with the quantitative RT-PCR result and showed that the accumulation of OsRDR6 protein in the OsRDR6 OE lines was clearly decreased after RDV infection (Fig. 4b). These data indicated that over-expression of OsRDR6 in rice plant had no significant effect on host response to RDV infection, and the decreased accumulation of OsRDR6 protein in the RDV-infected OE lines might be caused by a translational suppression of OsRDR6 and/or the stability of the protein.


OsRDR6 plays role in host defense against double-stranded RNA virus, Rice Dwarf Phytoreovirus.

Hong W, Qian D, Sun R, Jiang L, Wang Y, Wei C, Zhang Z, Li Y - Sci Rep (2015)

RDV infection reduced the expression of OsRDR6 in the OsRDR6-over-expression rice plants.(a) Relative expression levels of OsRDR6 RNA transcript in the OsRDR6 OE, EV and WT plants. Relative transcript levels were calculated using the 2−ΔΔC(t) method and OsEF-1a gene transcripts as the internal control. The error bars indicate the standard errors. Asterisks indicate P values compared with healthy rice plants: * P < 0.05; ** P < 0.01 (Student’s t test). (b) Western blot assay of OsRDR6 proteins accumulation in OsRDR6 OE, EV and WT plants. Expression of rice Hsp90 protein was used as the loading control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
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f4: RDV infection reduced the expression of OsRDR6 in the OsRDR6-over-expression rice plants.(a) Relative expression levels of OsRDR6 RNA transcript in the OsRDR6 OE, EV and WT plants. Relative transcript levels were calculated using the 2−ΔΔC(t) method and OsEF-1a gene transcripts as the internal control. The error bars indicate the standard errors. Asterisks indicate P values compared with healthy rice plants: * P < 0.05; ** P < 0.01 (Student’s t test). (b) Western blot assay of OsRDR6 proteins accumulation in OsRDR6 OE, EV and WT plants. Expression of rice Hsp90 protein was used as the loading control.
Mentions: To investigate the effect of RDV infection on OsRDR6 expression in rice plants, we analyzed OsRDR6 mRNA and protein accumulation in the RDV-inoculated and non-inoculated OsRDR6 OE, EV and WT rice plants through quantitative RT-PCR. Results of the assay showed that the levels of OsRDR6 mRNA were much higher in the OE plants than those in the WT or EV control plants (Fig. 4a). Interestingly, RDV infection resulted in decreased levels of OsRDR6 transcripts in all assayed plants. Western blot assay agreed with the quantitative RT-PCR result and showed that the accumulation of OsRDR6 protein in the OsRDR6 OE lines was clearly decreased after RDV infection (Fig. 4b). These data indicated that over-expression of OsRDR6 in rice plant had no significant effect on host response to RDV infection, and the decreased accumulation of OsRDR6 protein in the RDV-infected OE lines might be caused by a translational suppression of OsRDR6 and/or the stability of the protein.

Bottom Line: We found previously that rice RDR6 (OsRDR6) functioned in the defense against Rice stripe virus (RSV), and Rice Dwarf Phytoreovirus (RDV) infection resulted in down-regulation of expression of RDR6.Our result showed that down-regulation of OsRDR6 through the antisense (OsRDR6AS) strategy increased rice susceptibility to RDV infection while over-expression of OsRDR6 had no effect on RDV infection.The accumulation of RDV vsiRNAs was reduced in the OsRDR6AS plants.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing 100871, China.

ABSTRACT
RNAi is a major antiviral defense response in plant and animal model systems. RNA-dependent RNA polymerase 6 (RDR6) is an essential component of RNAi, which plays an important role in the resistance against viruses in the model plants. We found previously that rice RDR6 (OsRDR6) functioned in the defense against Rice stripe virus (RSV), and Rice Dwarf Phytoreovirus (RDV) infection resulted in down-regulation of expression of RDR6. Here we report our new findings on the function of OsRDR6 against RDV. Our result showed that down-regulation of OsRDR6 through the antisense (OsRDR6AS) strategy increased rice susceptibility to RDV infection while over-expression of OsRDR6 had no effect on RDV infection. The accumulation of RDV vsiRNAs was reduced in the OsRDR6AS plants. In the OsRDR6 over-expressed plants, the levels of OsRDR6 RNA transcript and protein were much higher than that in the control plants. Interestingly, the accumulation level of OsRDR6 protein became undetectable after RDV infection. This finding indicated that the translation and/or stability of OsRDR6 protein were negatively impacted upon RDV infection. This new finding provides a new light on the function of RDR6 in plant defense response and the cross-talking between factors encoded by host plant and double-stranded RNA viruses.

No MeSH data available.


Related in: MedlinePlus