TY  - EJOU
AU  - Fu, Xianrong 
AU  - Song, Aiping 
AU  - Peng, Bo 
AU  - Li, Song 
AU  - Liu, Weixin 
AU  - Zhang, Lingling 
AU  - Jiang, Jiafu 
AU  - Chen, Sumei 
AU  - Chen, Fadi 

TI  - Brassinosteroid Biosynthetic Gene <i>CmDWF4</i> Regulates Bud Outgrowth in <i>Chrysanthemum morifolium</i>
T2  - Phyton-International Journal of Experimental Botany

PY  - 2023
VL  - 92
IS  - 6
SN  - 1851-5657

AB  - Brassinosteroids (BRs), a class of steroid phytohormones, play a critical role in plant growth and development. The <i>DWF4</i> gene encodes a cytochrome P450 enzyme (CYP90B1), which is considered a rate-limiting enzyme in BR biosynthesis. Here, we identified a homologous gene of <i>DWF4</i> in chrysanthemum, <i>CmDWF4</i>. This gene was predicted to encode 491 amino acid residues with a molecular weight of 56.2 kDa and an isoelectric point (pI) of 9.10. Overexpression of <i>CmDWF4</i> in chrysanthemum was found to significantly increase growth rate, number, and length of lateral buds. Transcriptome analysis showed that multiple xyloglucan endotransglycosylase/hydrolase (XTH) family encoding genes associated with cell wall modification were up-regulated in <i>CmDWF4</i>-overexpressing lines. qRT-PCR assay confirmed the up-regulation of <i>CmXTH6</i>, <i>CmXTH23</i>, and <i>CmXTH28</i> in <i>CmDWF4</i>-overexpression line. Overall, this work establishes a mechanism by which BR biosynthetic gene <i>CmDWF4</i> promotes lateral bud outgrowth in chrysanthemum, possibly through regulating cell elongation and expansion.
KW  - BR; axillary bud; shoot branching; XTHs; cell elongation

DO  - 10.32604/phyton.2023.027870