@Article{phyton.2022.021062,
AUTHOR = {Yanqing Wu, Jiao Liu, Yuhan Tang, Daqiu Zhao, Jun Tao},
TITLE = {Age-Related Alterations in DNA Methylation and <i>APETALA2</i> (<i>AP2</i>) Levels in Herbaceous Peony (<i>Paeonia lactiflora</i> Pall.)},
JOURNAL = {Phyton-International Journal of Experimental Botany},
VOLUME = {91},
YEAR = {2022},
NUMBER = {9},
PAGES = {2005--2016},
URL = {http://www.techscience.com/phyton/v91n9/47717},
ISSN = {1851-5657},
ABSTRACT = {The ornamental and commercial values of herbaceous peony <i>(Paeonia lactiflora</i> Pall<i>.)</i> are directly related to its flower pattern. However, the molecular mechanisms underlying the type formation of <i>P. lactiflora</i> flowers have not been studied in great detail. Previous studies identified, using integrated multipleomics analysis, revealed that <i>APETALA2 (AP2)</i> is an important candidate gene that modulates type formation of <i>P. lactiflora</i> flowers. To further reveal the expression mechanism of <i>AP2</i> in <i>P. lactiflora</i> petals, we examined the profile of <i>AP2</i> expression in the inner and outer petals of ‘ZiFengyu’ at various developmental stages using qRT-PCR and BSP+Miseq methylation analysis. Based on our data, the <i>AP2</i> levels in the outer petals were obviously increased, relative to the inner petals. In addition, the S3 levels at the bloom stage were significantly higher than at the flower-bud stage S1, thereby promoting bloom stage S2, while declining stage S4. Using chromosome walking, the 2000 bp of the 5′-end upstream promoter region was achieved. This region harbored a CpG island (−665∼−872 bp), with multiple essential transcription factor binding sites (TFBS) such as NF-kappa B, GATA-1, Sp1, and C/EBP. Methylation sequencing revealed 7 methylated CpG sites in the CpG island region of the <i>AP2</i> promoter, thereinto, the methylation ratio of the CpG-3 site in the inner petals was significantly higher than in the outer petals. Correlation analysis revealed a negative association between the level of methylation (CpG-3, CpG-6), and <i>AP2</i> mRNA expression. CpG-3 was located on the Sp1 transcription factor binding site. Thus, we speculated that the CpG-3 methylation may inhibit transcription factor Sp1 binding to the gene promoter, thereby regulating <i>AP2</i> expression. Herein, we examined the role of <i>AP2</i> in the determination of flower patterns in <i>P. lactiflora</i>. Our conclusion will provide theoretical guidance for the molecular breeding of the flower pattern in <i>P. lactiflora</i>.},
DOI = {10.32604/phyton.2022.021062}
}