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The Roles of Arabidopsis CDF2 in Transcriptional and Posttranscriptional Regulation of Primary MicroRNAs.

Sun Z, Guo T, Liu Y, Liu Q, Fang Y - PLoS Genet. (2015)

Bottom Line: CDF2 binds directly to the promoters of some miRNAs and works as a transcription activator or repressor for these miRNA genes.CDF2 binds preferentially to the pri-miRNAs regulated by itself and affects DCL1-mediated processing of these pri-miRNAs.We conclude that CDF2 regulates a group of pri-miRNAs at both the transcriptional and posttranscriptional levels to maintain proper levels of their mature miRNAs to control plant development.

View Article: PubMed Central - PubMed

Affiliation: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.

ABSTRACT
The precise regulation of microRNA (miRNA) transcription and processing is important for eukaryotic development. Plant miRNAs are first transcribed as stem-loop primary miRNAs (pri-miRNAs) by RNA polymerase II,then cleaved in the nucleus into mature miRNAs by Dicer-like 1 (DCL1). We identified a cycling DOF transcription factor, CDF2, which interacts with DCL1 and regulates the accumulation of a population of miRNAs. CDF2 binds directly to the promoters of some miRNAs and works as a transcription activator or repressor for these miRNA genes. CDF2 binds preferentially to the pri-miRNAs regulated by itself and affects DCL1-mediated processing of these pri-miRNAs. Genetically, CDF2 works in the same pathway as miR156 or miR172 to control flowering. We conclude that CDF2 regulates a group of pri-miRNAs at both the transcriptional and posttranscriptional levels to maintain proper levels of their mature miRNAs to control plant development.

No MeSH data available.


Related in: MedlinePlus

CDF2 is in the same pathway as miR156 and miR172 to regulate flowering.(A) and (B) 24-day-old plants of indicated genotypes grown in longday photoperiods (16 hours light, 8 hours dark). (C) The time of flowering at the time of flowering of the indicated genotypes shown in A and B. Data are mean ± SEM of 50 plants. (D) The number of rosette leaves at the time of flowering of the indicated genotypes shown in A and B. Data are means ± SEM of 50 plants.
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pgen.1005598.g006: CDF2 is in the same pathway as miR156 and miR172 to regulate flowering.(A) and (B) 24-day-old plants of indicated genotypes grown in longday photoperiods (16 hours light, 8 hours dark). (C) The time of flowering at the time of flowering of the indicated genotypes shown in A and B. Data are mean ± SEM of 50 plants. (D) The number of rosette leaves at the time of flowering of the indicated genotypes shown in A and B. Data are means ± SEM of 50 plants.

Mentions: Several CDF2-regulated miRNAs are involved in flowering, including miR156, miR160, miR167, miR172, miR165/miR166, and miR319 [38], we investigated if miRNAs contribute to the earlier flowering phenotype of cdf2 mutant [11]. We focused on miR156 and miR172, two widely studied miRNAs [40] (S1 Table). It was reported that miR156 mutant line flowers earlier and miR172 mutant flowers later [38,41], in accordance to the early flowering phenotype of the cdf2 mutant in which the level of miR156 decreases (S1 Table) and its target squamosa promoter binding protein-like (SPL) proteins increase (S13A Fig), whereas miR172 increases (S1 Table) and its target AP2 decreases in cdf2 (S13B Fig) [42,43], supporting a role of CDF2 in miRNA regulation. We then first investigated the genetic relationship between CDF2 and miR156. To this end, we generated miR156a/miR156c/cdf2 triple mutant and found that the flowering time of this triple mutant flowered not earlier than either cdf2 or miR156a/ miR156c lines (Fig 6A, 6C and 6D), suggesting that CDF2 and miR156 regulate flowering through the same pathway. In addition, miR156 overexpression in cdf2 mutant showed the same late flowering phenotype as miR156 overexpression in Col (Figs 6A, 6C, 6D, S10 and S13A), indicating that miR156 acts genetically downstream of CDF2 to regulate flowering. Next, we overexpressed miR172 in cdf2 mutant and found that this overexpression line (p35S::miR172/cdf2) did not display earlier flowering phenotype than cdf2 mutant or miR172 overexpressed line in Col (Figs 6B–6D, S10 and S13B), suggesting that cdf2 and miR172 regulate flowering through the same signaling pathway. Together, these results indicated the role of CDF2 in miR156 activation and miR172 suppression which participate in the flowering time control. We next generated cdf2/hyl1 double mutants, we found that the flowering of cdf2/hyl1-2 plants was similar to the hyl1-2 single mutant [11,44] (S14A–S14C Fig), suggesting that CDF2 and HYL1 regulate flowering through the same pathway. CDF2 was reported to be a transcriptional repressor of constans (CO) to control flowering, our results thus revealed a new pathway for regulating the flowering through CDF2 and miRNAs which might be independent of CO.


The Roles of Arabidopsis CDF2 in Transcriptional and Posttranscriptional Regulation of Primary MicroRNAs.

Sun Z, Guo T, Liu Y, Liu Q, Fang Y - PLoS Genet. (2015)

CDF2 is in the same pathway as miR156 and miR172 to regulate flowering.(A) and (B) 24-day-old plants of indicated genotypes grown in longday photoperiods (16 hours light, 8 hours dark). (C) The time of flowering at the time of flowering of the indicated genotypes shown in A and B. Data are mean ± SEM of 50 plants. (D) The number of rosette leaves at the time of flowering of the indicated genotypes shown in A and B. Data are means ± SEM of 50 plants.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4608766&req=5

pgen.1005598.g006: CDF2 is in the same pathway as miR156 and miR172 to regulate flowering.(A) and (B) 24-day-old plants of indicated genotypes grown in longday photoperiods (16 hours light, 8 hours dark). (C) The time of flowering at the time of flowering of the indicated genotypes shown in A and B. Data are mean ± SEM of 50 plants. (D) The number of rosette leaves at the time of flowering of the indicated genotypes shown in A and B. Data are means ± SEM of 50 plants.
Mentions: Several CDF2-regulated miRNAs are involved in flowering, including miR156, miR160, miR167, miR172, miR165/miR166, and miR319 [38], we investigated if miRNAs contribute to the earlier flowering phenotype of cdf2 mutant [11]. We focused on miR156 and miR172, two widely studied miRNAs [40] (S1 Table). It was reported that miR156 mutant line flowers earlier and miR172 mutant flowers later [38,41], in accordance to the early flowering phenotype of the cdf2 mutant in which the level of miR156 decreases (S1 Table) and its target squamosa promoter binding protein-like (SPL) proteins increase (S13A Fig), whereas miR172 increases (S1 Table) and its target AP2 decreases in cdf2 (S13B Fig) [42,43], supporting a role of CDF2 in miRNA regulation. We then first investigated the genetic relationship between CDF2 and miR156. To this end, we generated miR156a/miR156c/cdf2 triple mutant and found that the flowering time of this triple mutant flowered not earlier than either cdf2 or miR156a/ miR156c lines (Fig 6A, 6C and 6D), suggesting that CDF2 and miR156 regulate flowering through the same pathway. In addition, miR156 overexpression in cdf2 mutant showed the same late flowering phenotype as miR156 overexpression in Col (Figs 6A, 6C, 6D, S10 and S13A), indicating that miR156 acts genetically downstream of CDF2 to regulate flowering. Next, we overexpressed miR172 in cdf2 mutant and found that this overexpression line (p35S::miR172/cdf2) did not display earlier flowering phenotype than cdf2 mutant or miR172 overexpressed line in Col (Figs 6B–6D, S10 and S13B), suggesting that cdf2 and miR172 regulate flowering through the same signaling pathway. Together, these results indicated the role of CDF2 in miR156 activation and miR172 suppression which participate in the flowering time control. We next generated cdf2/hyl1 double mutants, we found that the flowering of cdf2/hyl1-2 plants was similar to the hyl1-2 single mutant [11,44] (S14A–S14C Fig), suggesting that CDF2 and HYL1 regulate flowering through the same pathway. CDF2 was reported to be a transcriptional repressor of constans (CO) to control flowering, our results thus revealed a new pathway for regulating the flowering through CDF2 and miRNAs which might be independent of CO.

Bottom Line: CDF2 binds directly to the promoters of some miRNAs and works as a transcription activator or repressor for these miRNA genes.CDF2 binds preferentially to the pri-miRNAs regulated by itself and affects DCL1-mediated processing of these pri-miRNAs.We conclude that CDF2 regulates a group of pri-miRNAs at both the transcriptional and posttranscriptional levels to maintain proper levels of their mature miRNAs to control plant development.

View Article: PubMed Central - PubMed

Affiliation: National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China.

ABSTRACT
The precise regulation of microRNA (miRNA) transcription and processing is important for eukaryotic development. Plant miRNAs are first transcribed as stem-loop primary miRNAs (pri-miRNAs) by RNA polymerase II,then cleaved in the nucleus into mature miRNAs by Dicer-like 1 (DCL1). We identified a cycling DOF transcription factor, CDF2, which interacts with DCL1 and regulates the accumulation of a population of miRNAs. CDF2 binds directly to the promoters of some miRNAs and works as a transcription activator or repressor for these miRNA genes. CDF2 binds preferentially to the pri-miRNAs regulated by itself and affects DCL1-mediated processing of these pri-miRNAs. Genetically, CDF2 works in the same pathway as miR156 or miR172 to control flowering. We conclude that CDF2 regulates a group of pri-miRNAs at both the transcriptional and posttranscriptional levels to maintain proper levels of their mature miRNAs to control plant development.

No MeSH data available.


Related in: MedlinePlus