Interaction of small RNA-8105 and the intron ofIbMYB1RNA regulatesIbMYB1family genes through secondary siRNAs and DNA methylation after wounding

2013 ◽  
Vol 75 (5) ◽  
pp. 781-794 ◽  
Author(s):  
Jeng-Shane Lin ◽  
Chih-Ching Lin ◽  
Yu-Chi Li ◽  
Ming-Tsung Wu ◽  
Mong-Hsun Tsai ◽  
...  
2021 ◽  
Author(s):  
Jaemyung Choi ◽  
David Bruce Lyons ◽  
Daniel Zilberman

Flowering plants utilize small RNA molecules to guide DNA methyltransferases to genomic sequences. This RNA-directed DNA methylation (RdDM) pathway preferentially targets euchromatic transposable elements. However, RdDM is thought to be recruited by methylation of histone H3 at lysine 9 (H3K9me), a hallmark of heterochromatin. How RdDM is targeted to euchromatin despite an affinity for H3K9me is unclear. Here we show that loss of histone H1 enhances heterochromatic RdDM, preferentially at nucleosome linker DNA. Surprisingly, this does not require SHH1, the RdDM component that binds H3K9me. Furthermore, H3K9me is dispensable for RdDM, as is CG DNA methylation. Instead, we find that non-CG methylation is specifically required for small RNA biogenesis, and without H1 small RNA production quantitatively expands to non-CG methylated loci. Our results demonstrate that H1 enforces the separation of euchromatic and heterochromatic DNA methylation pathways by excluding the small RNA-generating branch of RdDM from non-CG methylated heterochromatin.


DNA Research ◽  
2018 ◽  
Vol 25 (5) ◽  
pp. 511-520 ◽  
Author(s):  
Satoshi Takahashi ◽  
Kenji Osabe ◽  
Naoki Fukushima ◽  
Shohei Takuno ◽  
Naomi Miyaji ◽  
...  

2008 ◽  
Vol 28 (1) ◽  
pp. 48-57 ◽  
Author(s):  
Lucia Daxinger ◽  
Tatsuo Kanno ◽  
Etienne Bucher ◽  
Johannes van der Winden ◽  
Ulf Naumann ◽  
...  

2014 ◽  
Author(s):  
Qingxin Song ◽  
Xueying Guan ◽  
Z. Jeffrey Chen

Cotton is the largest source of renewable textile fiber and a successful model of transgenic applications in crop production. However, improving cotton production using fiber-related transgenes is somewhat difficult. This is probably related to unique epigenetic and gene expression changes during fiber development. Here we show that inhibiting DNA methylation impairs fiber development. Genome-wide methylcytosine-, mRNA-, and small RNA-sequencing analyses reveal minor changes in CG and CHG methylation and distinct changes in CHH methylation among different tissues. In ovules CHH hypermethyaltion is associated with small RNA-directed DNA methylation (RdDM) and expression changes of nearby genes in euchromatin. Remarkably, ovule-derived fiber cells not only maintain euchromatic CHH methylation, but also generate additional heterochromatic CHH hypermethylation independent of RdDM, which represses transposable elements (TEs) and nearby genes including fiber-related genes. Furthermore, DNA methylation contributes to the expression bias of homoeologous genes in ovules and fibers. This spatiotemporal DNA methylation in promoters could act as a double-lock feedback mechanism to regulate TE and gene expression, which could be translated into genomic and biotechnological improvement of agronomic traits.


2020 ◽  
Author(s):  
Kaushik Panda ◽  
R. Keith Slotkin

AbstractHigh-quality transcript-based annotations of genes facilitates both genome-wide analyses and detailed single locus research. In contrast, transposable element (TE) annotations are rudimentary, consisting of only information on location and type of TE. When analyzing TEs, their repetitiveness and limited annotation prevents the ability to distinguish between potentially functional expressed elements and degraded copies. To improve genome-wide TE bioinformatics, we performed long-read Oxford Nanopore sequencing of cDNAs from Arabidopsis lines deficient in multiple layers of TE repression. We used these uniquely-mapping transcripts to identify the set of TEs able to generate mRNAs, and created a new transcript-based annotation of TEs that we have layered upon the existing high-quality community standard TAIR10 annotation. The improved annotation enables us to test specific standing hypotheses in the TE field. We demonstrate that inefficient TE splicing does not trigger small RNA production, and the cell more strongly targets DNA methylation to TEs that have the potential to make mRNAs. This work provides a transcript-based TE annotation for Arabidopsis, and serves as a blueprint to reduce the genomic complexity associated with repetitive TEs in any organism.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jaemyung Choi ◽  
David B Lyons ◽  
Daniel Zilberman

Flowering plants utilize small RNA molecules to guide DNA methyltransferases to genomic sequences. This RNA-directed DNA methylation (RdDM) pathway preferentially targets euchromatic transposable elements. However, RdDM is thought to be recruited by methylation of histone H3 at lysine 9 (H3K9me), a hallmark of heterochromatin. How RdDM is targeted to euchromatin despite an affinity for H3K9me is unclear. Here we show that loss of histone H1 enhances heterochromatic RdDM, preferentially at nucleosome linker DNA. Surprisingly, this does not require SHH1, the RdDM component that binds H3K9me. Furthermore, H3K9me is dispensable for RdDM, as is CG DNA methylation. Instead, we find that non-CG methylation is specifically associated with small RNA biogenesis, and without H1 small RNA production quantitatively expands to non-CG methylated loci. Our results demonstrate that H1 enforces the separation of euchromatic and heterochromatic DNA methylation pathways by excluding the small RNA-generating branch of RdDM from non-CG methylated heterochromatin.


2021 ◽  
Author(s):  
Tania Chakraborty ◽  
Joshua T Trujillo ◽  
Timmy Kendall ◽  
Rebecca A Mosher

All eukaryotes possess three DNA-dependent RNA polymerases, Pols I-III, while land plants possess two additional polymerases, Pol IV and Pol V. Derived through duplication of Pol II subunits, Pol IV produces 24-nt siRNAs that interact with Pol V transcripts to target de novo DNA methylation and silence transcription of transposons. Members of the grass family encode additional duplicated subunits of Pol IV and V, raising questions regarding the function of each paralog. In this study, we identify a null allele of the putative Pol IV second subunit, NRPD2, and demonstrate that NRPD2 is the sole subunit functioning with NRPD1 in small RNA production and CHH methylation in leaves. Homozygous nrpd2 mutants have neither gametophytic defects, nor embryo lethality, although adult plants are dwarf and sterile.


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