HD-ZIP Transcription Factors and Brassinosteroid Signaling Play a Role in Capitulum Patterning in Chrysanthemum
Chrysanthemum is a genus in the Asteraceae family containing numerous cut flower varieties with high ornamental value. It owes its beauty to the composite flower head, which resembles a compact inflorescence. This structure is also known as a capitulum, in which many ray and disc florets are densely...
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MDPI AG
2023-04-01
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| Series: | International Journal of Molecular Sciences |
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| author | Annemarie Castricum Erin H. Bakker Nick C. M. H. de Vetten Mieke Weemen Gerco C. Angenent Richard G. H. Immink Marian Bemer |
| author_facet | Annemarie Castricum Erin H. Bakker Nick C. M. H. de Vetten Mieke Weemen Gerco C. Angenent Richard G. H. Immink Marian Bemer |
| author_sort | Annemarie Castricum |
| collection | DOAJ |
| description | Chrysanthemum is a genus in the Asteraceae family containing numerous cut flower varieties with high ornamental value. It owes its beauty to the composite flower head, which resembles a compact inflorescence. This structure is also known as a capitulum, in which many ray and disc florets are densely packed. The ray florets are localized at the rim, are male sterile, and have large colorful petals. The centrally localized disc florets develop only a small petal tube but produce fertile stamens and a functional pistil. Nowadays, varieties with more ray florets are bred because of their high ornamental value, but, unfortunately, this is at the expense of their seed setting. In this study, we confirmed that the disc:ray floret ratio is highly correlated to seed set efficiency, and therefore, we further investigated the mechanisms that underlie the regulation of the disc:ray floret ratio. To this end, a comprehensive transcriptomics analysis was performed in two acquired mutants with a higher disc:ray floret ratio. Among the differentially regulated genes, various potential brassinosteroid (BR) signaling genes and HD-ZIP class IV homeodomain transcription factors stood out. Detailed follow-up functional studies confirmed that reduced BR levels and downregulation of HD-ZIP IV gene <i>Chrysanthemum morifolium PROTODERMAL FACTOR 2</i> (<i>CmPDF2</i>) result in an increased disc:ray floret ratio, thereby providing ways to improve seed set in decorative chrysanthemum varieties in the future. |
| first_indexed | 2024-03-11T04:55:18Z |
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| id | doaj.art-9c5ac9af49884160aa0b4e168f3a47d2 |
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| issn | 1661-6596 1422-0067 |
| language | English |
| last_indexed | 2024-03-11T04:55:18Z |
| publishDate | 2023-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-9c5ac9af49884160aa0b4e168f3a47d22023-11-17T19:43:45ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672023-04-01248765510.3390/ijms24087655HD-ZIP Transcription Factors and Brassinosteroid Signaling Play a Role in Capitulum Patterning in ChrysanthemumAnnemarie Castricum0Erin H. Bakker1Nick C. M. H. de Vetten2Mieke Weemen3Gerco C. Angenent4Richard G. H. Immink5Marian Bemer6Bioscience, Wageningen University & Research, 6700 AA Wageningen, The NetherlandsDekker Chrysanten, 1711 RP Hensbroek, The NetherlandsDekker Chrysanten, 1711 RP Hensbroek, The NetherlandsBioscience, Wageningen University & Research, 6700 AA Wageningen, The NetherlandsBioscience, Wageningen University & Research, 6700 AA Wageningen, The NetherlandsBioscience, Wageningen University & Research, 6700 AA Wageningen, The NetherlandsBioscience, Wageningen University & Research, 6700 AA Wageningen, The NetherlandsChrysanthemum is a genus in the Asteraceae family containing numerous cut flower varieties with high ornamental value. It owes its beauty to the composite flower head, which resembles a compact inflorescence. This structure is also known as a capitulum, in which many ray and disc florets are densely packed. The ray florets are localized at the rim, are male sterile, and have large colorful petals. The centrally localized disc florets develop only a small petal tube but produce fertile stamens and a functional pistil. Nowadays, varieties with more ray florets are bred because of their high ornamental value, but, unfortunately, this is at the expense of their seed setting. In this study, we confirmed that the disc:ray floret ratio is highly correlated to seed set efficiency, and therefore, we further investigated the mechanisms that underlie the regulation of the disc:ray floret ratio. To this end, a comprehensive transcriptomics analysis was performed in two acquired mutants with a higher disc:ray floret ratio. Among the differentially regulated genes, various potential brassinosteroid (BR) signaling genes and HD-ZIP class IV homeodomain transcription factors stood out. Detailed follow-up functional studies confirmed that reduced BR levels and downregulation of HD-ZIP IV gene <i>Chrysanthemum morifolium PROTODERMAL FACTOR 2</i> (<i>CmPDF2</i>) result in an increased disc:ray floret ratio, thereby providing ways to improve seed set in decorative chrysanthemum varieties in the future.https://www.mdpi.com/1422-0067/24/8/7655Chrysanthemumcapitulumdisc floretray floretHD-ZIP IVbrassinosteroids |
| spellingShingle | Annemarie Castricum Erin H. Bakker Nick C. M. H. de Vetten Mieke Weemen Gerco C. Angenent Richard G. H. Immink Marian Bemer HD-ZIP Transcription Factors and Brassinosteroid Signaling Play a Role in Capitulum Patterning in Chrysanthemum International Journal of Molecular Sciences Chrysanthemum capitulum disc floret ray floret HD-ZIP IV brassinosteroids |
| title | HD-ZIP Transcription Factors and Brassinosteroid Signaling Play a Role in Capitulum Patterning in Chrysanthemum |
| title_full | HD-ZIP Transcription Factors and Brassinosteroid Signaling Play a Role in Capitulum Patterning in Chrysanthemum |
| title_fullStr | HD-ZIP Transcription Factors and Brassinosteroid Signaling Play a Role in Capitulum Patterning in Chrysanthemum |
| title_full_unstemmed | HD-ZIP Transcription Factors and Brassinosteroid Signaling Play a Role in Capitulum Patterning in Chrysanthemum |
| title_short | HD-ZIP Transcription Factors and Brassinosteroid Signaling Play a Role in Capitulum Patterning in Chrysanthemum |
| title_sort | hd zip transcription factors and brassinosteroid signaling play a role in capitulum patterning in chrysanthemum |
| topic | Chrysanthemum capitulum disc floret ray floret HD-ZIP IV brassinosteroids |
| url | https://www.mdpi.com/1422-0067/24/8/7655 |
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