Application of 5-azacytidine induces DNA hypomethylation and accelerates dormancy release in buds of tree peony
Application of 5-azacytidine induces DNA hypomethylation and accelerates dormancy release in buds of tree peony
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施用5-氮杂胞苷诱导牡丹芽DNA低甲基化并加速休眠解除
DOI：
10.1016/j.plaphy.2019.12.010
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发表时间：
2020
影响因子：
6.5
通讯作者：
Gai Shupeng
中科院分区：
文献类型：
--
作者：
Zhang Yuxi;Si Fuhui;Wang Yanyan;Liu Chunying;Zhang Tao;Yuan Yanchao;Gai Shupeng
解除芽休眠是牡丹等多年生植物恢复生长和生产的先决条件。DNA甲基化在调控基因表达中起着关键作用。形态学观察和DNA甲基化分析结果表明，5-azaC处理7 d后，5 mC含量下降，促进休眠解除。5-azaC处理后，通过RNA-seq共获得174，341个单一基因和1818个差异表达基因（DEG），其中5-azaC处理1 d后（AD 1 vs CD 1）的DEG为1194个，处理7 d后（AD 7 vs CD 7）的DEG为624个。KEGG途径分析表明，AD 7与CD 7相比，共有10个DNA复制途径中注释的DEG富集。此外，通过实时定量RT-PCR的几种DEG的表达模式与RNA-seq数据的表达模式一致。5-azaC处理显著降低了DNA甲基转移酶基因PsCMT 3、PsMET 1和PsDRM 2的表达水平，提高了去甲基化酶基因PsROS 1的转录水平。同时，总甲基转移酶活性下降，脱甲基酶活性被5-azaC诱导。综上所述，5-azaC的施用在短期内抑制了植物生长发育相关基因的表达，可能对植物产生毒害作用;长期效应是通过增加脱甲基酶基因的转录量和降低甲基转移酶基因的表达量，诱导植物低甲基化，进而激活细胞周期、DNA复制和糖代谢过程，加速休眠解除。这为进一步研究牡丹休眠解除的分子机制提供了新的思路。
Release of bud dormancy is a prerequisite for the growth resumption and production in perennial plants such as tree peony. DNA methylation plays a pivotal role in regulating gene expression. In this study, combination of morphologic observation and DNA methylation analysis indicated that 5-azacytidine (5-azaC) application for 7 d declined 5 mC quantities and promoted dormancy release. After 5-azaC treatment, total 174,341 unigenes and 1818 differentially expression genes (DEGs) were obtained by RNA-seq, of which there were 1194 DEGs after 1 d 5-azaC treatment (AD1 vs CD1), and 624 DEGs after 7 d (AD7 vs CD7), respectively. The KEGG pathway analysis identified that totally 10 DEGs annotated in DNA replication pathway were enriched when AD7 compared with CD7. Furthermore, the expression patterns of several DEGs by real-time quantitative RT-PCR were consistent with that of RNA-seq data. 5-azaC application significantly decreased the expression levels of DNA methyltransferase genes,PsCMT3,PsMET1andPsDRM2, and increased the transcript of demethylase genePsROS1. Simultaneously, total methyltransferases activity decreased, and demethylase activity was induced by 5-azaC. In summary, application of 5-azaC inhibited the expression of the genes related to growth and development in short-term, indicating a possible toxic effect to plant, and its long-term effect was to induce hypomethylation by increasing demethylase genes transcripts and decreasing the expressions of methyltransferase genes, and then activate cell cycle, DNA replication and glycol-metabolism processes, which subsequently accelerated dormancy release. All these would provide a new strategy to further understand the molecular mechanism of dormancy release in tree peony.