Inhibition of post-transcriptional gene silencing of chalcone synthase genes in petunia picotee petals by fluacrypyrim
Inhibition of post-transcriptional gene silencing of chalcone synthase genes in petunia picotee petals by fluacrypyrim
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DOI：
10.1093/jxb/erz009
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发表时间：
2019-02-15
影响因子：
6.9
通讯作者：
Nakayama, Masayoshi
中科院分区：
文献类型：
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作者：
Ban, Yusuke;Morita, Yasumasa;Nakayama, Masayoshi
在矮牵牛（Petunia hybrida）品种的花瓣中，查尔酮合酶A（CHSA）的边缘特异性转录后基因沉默（PTGS）抑制花色素苷的生物合成，导致边缘白色组织的形成。在这项研究中，我们发现，低分子量的化合物，氟虫腈，抑制PTGS的CHSA，我们探讨了位点特异性PTGS的运作机制。Fluacrypyrim处理消除了picotee模式，消除了花青素相关化合物、CHSA表达和CHSA小干扰RNA（siRNA）水平的位点特异性差异。此外，氟啶虫胺消除了矮牵牛花型图案，这也是由CHSA的PTGS引起的。氟啶虫腈处理仅在早期花发育阶段有效，并且主要消除源自CHS基因的siRNA;即源自其他基因的siRNA保持在相当的水平。Fluacrypyrim可能靶向诱导特异性作用于矮牵牛花中CHS基因的PTGS，而不是降解mRNA并产生siRNA的常见PTGS维持机制。给药后，由于白色和着色部位之间的边界以时间和剂量依赖性方式向边缘移动，着色组织的比例增加。这些结果表明，氟啶虫脒靶向的PTGS诱导是逐渐完成的，其强度从边缘到矮牵牛picotee花瓣中心逐渐减弱。
In petals of picotee petunia (Petunia hybrida) cultivars, margin-specific post-transcriptional gene silencing (PTGS) of chalcone synthase A (CHSA) inhibits anthocyanin biosynthesis, resulting in marginal white tissue formation. In this study, we found that a low molecular mass compound, fluacrypyrim, inhibits PTGS of CHSA, and we explored the site-specific PTGS mechanism of operation. Fluacrypyrim treatment abolished the picotee pattern and eliminated site-specific differences in the levels of anthocyanin-related compounds, CHSA expression, and CHSA small interfering RNA (siRNA). In addition, fluacrypyrim abolished the petunia star-type pattern, which is also caused by PTGS of CHSA. Fluacrypyrim treatment was effective only at the early floral developmental stage and predominantly eliminated siRNA derived from CHS genes; i.e. siRNA derived from other genes remained at a comparable level. Fluacrypyrim probably targets the induction of PTGS that specifically operates for CHS genes in petunia picotee flowers, rather than common PTGS maintenance mechanisms that degrade mRNAs and generate siRNA. Upon treatment, the proportion of colored tissue increased due to a shift of the border between white and colored sites toward the margin in a time- and dose-dependent manner. These findings imply that the fluacrypyrim-targeted PTGS induction is completed gradually and its strength is attenuated from the margins to the center of petunia picotee petals.