Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia, 40-007 Katowice, Poland.
Polish Academy of Sciences Botanical Garden-Center for Biological Diversity Conservation in Powsin, Prawdziwka 2, 02-973 Warsaw, Poland.
Cells. 2022 Feb 17;11(4):718. doi: 10.3390/cells11040718.
In plants, the embryogenic transition of somatic cells requires the reprogramming of the cell transcriptome, which is under the control of genetic and epigenetic factors. Correspondingly, the extensive modulation of genes encoding transcription factors and miRNAs has been indicated as controlling the induction of somatic embryogenesis in Arabidopsis and other plants. Among the s that have a differential expression during somatic embryogenesis, members of the gene family have been identified, which implies a role of miR172 in controlling the embryogenic transition in Arabidopsis. In the present study, we found a disturbed expression of both and candidate miR172-target genes, including , , , , and , that negatively affected the embryogenic response of transgenic explants. Next, we examined the role of in the miR172-mediated mechanism that controls the embryogenic response. We found some evidence that by controlling , miR172 might repress the that has an important function in embryogenic induction. We showed that the mechanism of the miR172-AP2-controlled repression of involves histone acetylation. We observed the upregulation of the transcripts in an embryogenic culture that was overexpressing and treated with trichostatin A (TSA), which is an inhibitor of HDAC histone deacetylases. The increased expression of the gene in the embryogenic culture of the mutants further confirmed the role of histone acetylation in control during somatic embryogenesis. A chromatin-immunoprecipitation analysis provided evidence about the contribution of HDA6/19-mediated histone deacetylation to AP2-controlled repression during embryogenic induction. The upstream regulatory elements of the miR172-AP2-WUS pathway might involve the miR156-controlled SPL9/SPL10, which control the level of mature miR172 in an embryogenic culture.
在植物中，体细胞的胚胎发生转变需要细胞转录组的重新编程，这受遗传和表观遗传因素的控制。相应地，广泛调节编码转录因子和 miRNA 的基因已被表明控制拟南芥和其他植物的体细胞胚胎发生诱导。在体细胞胚胎发生过程中差异表达的 s 中，已经鉴定出了 基因家族的成员，这表明 miR172 在控制拟南芥的胚胎发生转变中起作用。在本研究中，我们发现 和候选 miR172 靶基因，包括 、 、 、 、 和 ，的表达都受到干扰，这对转基因外植体的胚胎发生反应产生了负面影响。接下来，我们研究了 在 miR172 调控的控制胚胎发生反应的机制中的作用。我们发现一些证据表明，通过控制 ，miR172 可能会抑制在胚胎发生诱导中具有重要功能的 。我们表明，miR172-AP2 控制的 抑制机制涉及组蛋白乙酰化。我们观察到在过表达 和用 Trichostatin A（TSA）处理的胚胎发生培养物中上调 转录本，TSA 是组蛋白去乙酰化酶 HDAC 的抑制剂。在 突变体的胚胎发生培养物中 基因的表达增加进一步证实了组蛋白乙酰化在体细胞胚胎发生过程中对 的控制作用。染色质免疫沉淀分析为 HDA6/19 介导的组蛋白去乙酰化对 AP2 控制的胚胎发生诱导过程中 抑制的贡献提供了证据。miR172-AP2-WUS 途径的上游调节元件可能涉及 miR156 控制的 SPL9/SPL10，其控制胚胎发生培养物中成熟 miR172 的水平。
