miR172 Regulates WUS during Somatic Embryogenesis in Arabidopsis via AP2

Abstract

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 MIRNAs that have a differential expression during somatic embryogenesis, members of the MIRNA172 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 MIRNA172 and candidate miR172-target genes, including AP2, TOE1, TOE2, TOE3, SMZ and SNZ, that negatively affected the embryogenic response of transgenic explants. Next, we examined the role of AP2 in the miR172-mediated mechanism that controls the embryogenic response. We found some evidence that by controlling AP2, miR172 might repress the WUS that has an important function in embryogenic induction. We showed that the mechanism of the miR172-AP2-controlled repression of WUS involves histone acetylation. We observed the upregulation of the WUS transcripts in an embryogenic culture that was overexpressing AP2 and treated with trichostatin A (TSA), which is an inhibitor of HDAC histone deacetylases. The increased expression of the WUS gene in the embryogenic culture of the hdac mutants further confirmed the role of histone acetylation in WUS control during somatic embryogenesis. A chromatin-immunoprecipitation analysis provided evidence about the contribution of HDA6/19-mediated histone deacetylation to AP2-controlled WUS 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.

Transgressive and parental dominant gene expression and cytosine methylation during seed development in Brassica napus hybrids

“…Interestingly, we observed differentially expressed miRNAs in early and late seed development among miRNA families which are normally involved in plant growth and development (Plotnikova et al 2019 ; Dong et al 2022 ; Verma et al 2022 ); thus, broadening the range and data availability of miRNAs in oilseed rape development, for example, miR172 regulates not only the flowering time pathway, but also embryo development by controlling APETALA 2 ( AP2 ) and AP2-like genes such as TOE2 (Boutilier et al 2002 ; Shivaraj et al 2018 ; Nowak et al 2022 ) was found in our study. miR165/166 families control leaf adaxial/abaxial development and embryogenesis by targeting the class III homeodomain leucine zipper (HD-ZIP III) transcription factor gene family which includes the REV , PHV and PHB (Wang et al 2007 ; Tang et al 2012 ).…”

Genome-Wide Identification of BTB Domain-Containing Gene Family in Grapevine (Vitis vinifera L.)

“…Similarly, F-box and GCN-4 were shown to be involved in cell cycle regulation and circadian control [67]. Furthermore, interaction analysis of BTB genes with V. vinifera-specific miRNAs revealed that selected BTB genes were targeted by various development-and stress-related miRNA families, such as vvi-miR169, vvi-miR172, vvi-miR399, vvi-miR482, vvi-miR535, vvi-miR390, vvi-miR395 and vvi-miR408 (Figure 7) [68][69][70][71][72][73][74][75][76][77][78][79]. In our study, we performed in silico analysis, which suggested the potential role of BTB genes in the regulation of different developmental stages and biotic and abiotic stresses in V. vinifera.…”

Role of a ZF-HD Transcription Factor in miR157-Mediated Feed-Forward Regulatory Module That Determines Plant Architecture in Arabidopsis

“…In Arabidopsis , miR156/7 and miR172 play roles in the juvenile and adult stages of vegetative development, with miR172 acting downstream of miR156. Dynamic antagonistic expression of the miR156 and miR172 families controls the transition from the vegetative to reproductive stages [ 21 , 50 ]. Both the [ 44 ] miRNA156/7 and miR172 families are highly conserved across plant species [ 30 ].…”