Gene Structural Specificity and Expression of <i>MADS-Box</i> Gene Family in <i>Camellia chekiangoleosa</i>
<i>MADS-box</i> genes encode transcription factors that affect plant growth and development. <i>Camellia chekiangoleosa</i> is an oil tree species with ornamental value, but there have been few molecular biological studies on the developmental regulation of this species. To e...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-02-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/24/4/3434 |
| Summary: | <i>MADS-box</i> genes encode transcription factors that affect plant growth and development. <i>Camellia chekiangoleosa</i> is an oil tree species with ornamental value, but there have been few molecular biological studies on the developmental regulation of this species. To explore their possible role in <i>C. chekiangoleosa</i> and lay a foundation for subsequent research, 89 <i>MADS-box</i> genes were identified across the whole genome of <i>C. chekiangoleosa</i> for the first time. These genes were present on all the chromosomes and were found to have expanded by tandem duplication and fragment duplication. Based on the results of a phylogenetic analysis, the 89 <i>MADS-box</i> genes could be divided into either type I (38) or type II (51). Both the number and proportion of the type II genes were significantly greater than those of <i>Camellia sinensis</i> and <i>Arabidopsis thaliana</i>, indicating that <i>C. chekiangoleosa</i> type II genes experienced a higher duplication rate or a lower loss rate. The results of both a sequence alignment and a conserved motif analysis suggest that the type II genes are more conserved, meaning that they may have originated and differentiated earlier than the type I genes did. At the same time, the presence of extra-long amino acid sequences may be an important feature of <i>C. chekiangoleosa</i>. Gene structure analysis revealed the number of introns of <i>MADS-box</i> genes: twenty-one type I genes had no introns, and 13 type I genes contained only 1~2 introns. The type II genes have far more introns and longer introns than the type I genes do. Some MIKC<sup>C</sup> genes have super large introns (≥15 kb), which are rare in other species. The super large introns of these MIKC<sup>C</sup> genes may indicate richer gene expression. Moreover, the results of a qPCR expression analysis of the roots, flowers, leaves and seeds of <i>C. chekiangoleosa</i> showed that the <i>MADS-box</i> genes were expressed in all those tissues. Overall, compared with that of the type I genes, the expression of the type II genes was significantly higher. The <i>CchMADS31</i> and <i>CchMADS58</i> genes (type II) were highly expressed specifically in the flowers, which may in turn regulate the size of the flower meristem and petals. <i>CchMADS55</i> was expressed specifically in the seeds, which might affect seed development. This study provides additional information for the functional characterization of the <i>MADS-box</i> gene family and lays an important foundation for in-depth study of related genes, such as those involved in the development of the reproductive organs of <i>C. chekiangoleosa</i>. |
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| ISSN: | 1661-6596 1422-0067 |