Correction: The Arabidopsis <i>miR472-RDR6</i> Silencing Pathway Modulates PAMP- and Effector-Triggered Immunity through the Post-transcriptional Control of Disease Resistance Genes

<p>Correction: The Arabidopsis <i>miR472-RDR6</i> Silencing Pathway Modulates PAMP- and Effector-Triggered Immunity through the Post-transcriptional Control of Disease Resistance Genes</p

Schematic representation illustrating the relationship between miR472/RDR6 through CNL regulation during Arabidopsis immunity.

<p>Schematic representation illustrating the relationship between miR472/RDR6 through CNL regulation during Arabidopsis immunity.</p

Enhanced basal resistance towards <i>Pto</i> DC3000 observed in the <i>rdr6</i> mutant requires SA and proper chaperoning of NLRs.

<p>(<b>A</b>) β-glucuronidase (GUS) activity in plants PR1p:GUS and <i>rdr6</i> PR1p:GUS plants reporting PR1 transcriptional activity in WT and <i>rdr6</i>-15 mutant, respectively. (<b>B</b>) The transcript level of PR1 and ICS1 were detected by RT-qPCR. Error bars indicate standard deviation from technical repeats. Expression levels are normalized to the same internal controls At2g36060, At4g29130, and At5g13440. (<b>C</b>) Bacterial growth in five- to six-week-old plants from WT, single <i>rdr6-15</i> and <i>sid2-2</i> mutants or double <i>rdr6-sid2</i> mutant infiltrated with <i>Pto</i> DC3000 (2×10⁵ CFU mL⁻¹). (<b>D</b>) Bacterial growth in five- to six-week-old plants from WT, simple <i>rdr6-15</i> and <i>npr1-1</i> mutants or double <i>rdr6-npr1</i> mutant infiltrated with <i>Pto</i> DC3000 (2×10⁵ CFU mL⁻¹). (<b>E</b>) Bacterial growth in five- to six-week-old plants from WT, single (<i>rdr6-15, rar1-21</i>) or double mutant (<i>rdr6-rar1</i>) infiltrated with <i>Pto</i> DC3000 (2×10⁵ CFU mL¹). F) Bacterial growth in five- to six-week-old plants from WT, single (<i>rdr6-15, rar1-21</i>) or double mutant (<i>rdr6-rar1</i>) infiltrated with <i>Pto</i> DC3000 (AvrPphB) (2 10⁵ CFU mL¹). For <b>C, D, E</b> and <b>F</b> values are average ± se of four leaf discs (n = 8). Wilcoxon test was performed to determine the significant differences between <i>rdr6</i> and double mutant plants. Asterisks “**” and “*” indicate statistically significant differences at a P value<0.01 and <0.05 respectively. Experiments were performed in two independent biological replicates with similar results.</p

RDR6 and AGO1 mRNA levels rapidly decrease after flg22 treatment.

<p>Seedlings were treated for 1, 2 and 4-qPCR. Expression levels are relative to three reference genes (At2g36060; At4g29130; At5g13440). The Log₂ of mRNA values are normalized to that of control WT seedlings or leaves plants treated or infiltrated with water. Error bars indicate standard deviation from technical repeats. Similar results were obtained in two independent experiments.</p

<i>RDR6</i> negatively regulates PTI responses.

<p>(<b>A</b>) H₂O₂-dependent luminescence upon H₂O or flg22 (100 nM) treatment in WT and <i>rdr6-15</i> leaf discs. (<b>B</b>) Expression levels of PAMP-responsive mRNAs, FRK1, WRKY22 and WRKY29 detected by RT-qPCR in leaves treated with 100 nM flg22 or water for 4 hours. (<b>C</b>) Callose deposition upon H₂O or flg22 (100 nM) treatment in WT and <i>rdr6-15</i> leaves blade at stage 7. Values are average ± se (standard error) with n = 25 to 30. (<b>D</b>) Bacterial growth in five- to six-week-old plants (WT or <i>rdr6</i>) 4 days after being sprayed (10⁸ CFU mL⁻¹) with <i>Pto</i> DC3000. Values are average ± se of four leaf discs (n = 8). Wilcoxon test was performed to determine the significant differences between <i>rdr6</i> and WT plants. Asterisk “**” indicates statistically significant differences (P<0.01). Experiments were performed in two independent biological replicates with similar results.</p

<i>MiR472</i>^m and <i>rdr6</i> are more resistant to <i>Pto</i> DC3000 (AvrPphB).

<p>(<b>A</b>) Bacterial growth in five- to six-week-old plants from WT, <i>rdr6</i> and <i>miR472^m</i> syringe-infiltrated with <i>Pto</i> DC3000 AvrPphB (2×10⁵ CFU mL⁻¹). Values are average ± se of four leaf discs (n = 8). Wilcoxon test was performed to determine the significant differences as compared to WT plants. As a positive control the susceptible mutant <i>rps5</i> (two independent mutant alleles SalK_127201 and SAIL_146_F01) has been used as control. Asterisk “*” indicates statistically significant differences at a P value<0.05. (<b>B</b>) Bacterial growth in five- to six-week-old plants from WT and miR472OE lines syringe-infiltrated with <i>Pto</i> DC3000 AvrPphB (2×10⁵ CFU mL⁻¹). Values are average ± se of four leaf discs (n = 8). Wilcoxon test was performed to determine the significant differences as compared to WT plants. These experiments were performed in two biological replicates with similar results.</p

<i>RDR6</i>-dependent siRNAs negatively regulate a subset of CNL transcripts both constitutively and during flg22 elicitation.

<p>(<b>A</b>) The transcript levels of At1g12220 (RPS5), At1g51480 (RSG1) and At5g43730 (RSG2) were detected by RT-qPCR in untreated seedlings. Results of expression represent the ratio <i>rdr6</i>/WT. (<b>B</b>) Transcript levels of RPS5, RSG1 and RSG2 by RT-qPCR in seedling treated or not with flg22 (100 nM) at different time-points. Results represent the ratio of the values between samples treated with flg22 relative to H₂O (mock) for <i>rdr6</i> and WT seedlings. Expression levels are always normalized to the same internal controls At2g36060, At4g29130, and At5g13440. Error bars indicate standard deviation from technical repeats. These experiments were performed in two biological replicates with similar results.</p

<i>MiR472</i> negatively regulates PTI responses and resistance against virulent <i>Pto</i> DC3000.

<p>(<b>A</b>) Expression levels of At1g12220 and At1g51480 detected by RT-qPCR in WT, miR472OE (overexpressor) and <i>miR472^m</i> (mutant) seedling treated with either H₂O or flg22 (100 nM) for 2 hours. (<b>B</b>) H₂O₂-dependent luminescence induced by flg22 (100 nM) in WT, miR472OE and miR472^m leaf discs. (<b>C</b>) Callose deposition induced by flg22 (100 nM) in WT, miR472OE and miR472^m leaves. (<b>D</b>) Bacterial growth in five- to six-week-old plants from WT, miR472OE and <i>miR472^m</i> infiltrated with <i>Pto</i> DC3000 (2×10⁵ CFU mL⁻¹). For C and D values are average ± se of four leaf discs (n = 8). Wilcoxon test was performed to determine the significant differences as compared to <i>rdr6</i> plants. Asterisks “*” and “**” indicate statistically significant differences at a P value<0.05 and <0.01 respectively. These experiments were performed in two biological replicates with similar results.</p

Correction: RNAi-Dependent and Independent Control of LINE1 Accumulation and Mobility in Mouse Embryonic Stem Cells

<p>Correction: RNAi-Dependent and Independent Control of LINE1 Accumulation and Mobility in Mouse Embryonic Stem Cells</p

RNAi-Dependent and Independent Control of LINE1 Accumulation and Mobility in Mouse Embryonic Stem Cells

<div><p>In most mouse tissues, long-interspersed elements-1 (L1s) are silenced <i>via</i> methylation of their 5′-untranslated regions (5′-UTR). A gradual loss-of-methylation in pre-implantation embryos coincides with L1 retrotransposition in blastocysts, generating potentially harmful mutations. Here, we show that Dicer- and Ago2-dependent RNAi restricts L1 accumulation and retrotransposition in undifferentiated mouse embryonic stem cells (mESCs), derived from blastocysts. RNAi correlates with production of Dicer-dependent 22-nt small RNAs mapping to overlapping sense/antisense transcripts produced from the L1 5′-UTR. However, RNA-surveillance pathways simultaneously degrade these transcripts and, consequently, confound the anti-L1 RNAi response. In <i>Dicer^−/−</i> mESC complementation experiments involving ectopic Dicer expression, L1 silencing was rescued in cells in which microRNAs remained strongly depleted. Furthermore, these cells proliferated and differentiated normally, unlike their non-complemented counterparts. These results shed new light on L1 biology, uncover defensive, in addition to regulatory roles for RNAi, and raise questions on the differentiation defects of <i>Dicer^−/−</i> mESCs.</p></div