Yang Ying, Gao Xiaolei, Xiong Huan, Yuan Deyi, Zou Feng
State Key Laboratory of Utilization of Woody Oil Resource, Central South University of Forestry and Technology, Changsha, China.
Key Laboratory of Cultivation and Protection for Non-Wood Forest Trees, Ministry of Education, Central South University of Forestry and Technology, Changsha, China.
Physiol Plant. 2025 May-Jun;177(3):e70345. doi: 10.1111/ppl.70345.
Gibberellins (GAs) play important roles in regulating reproductive development, especially flower development. However, the regulation of GA metabolism and GA signaling component genes of flower bud development in Camellia oleifera is not entirely understood. In this study, 6-year-old C. oleifera 'Huashuo' was used as the experimental material. Exogenous GA and GA biosynthesis inhibitors, chlormequat chloride (CCC) and uniconazole (UCZ), were applied to investigate the flower development, levels of GA, GA metabolism, and the expression of genes involved in GA signaling across the different treatments. Our results demonstrate that exogenous GA promoted flower bud growth and accelerated blooming, with the rate of petaloid-anther transformation reaching up to 64.11% during the peak blooming period. Cytological analysis showed that the anthers in the GA-treated flowers exhibited abnormal longitudinal elongation 30 days after spraying, and gradually developed into petaloid anthers. KEGG analysis revealed that the GA treatment regulated the plant hormone signal transduction. The genes encoding DELLA protein accounted for the largest proportion (52.45%) of the gibberellin signal transduction pathway DEGs. GA enhanced gibberellin content by regulating the gibberellin biosynthesis gene CoGA20ox1 during early flower development, and GID1 also showed a significant response to GAs. Additionally, the expression of genes associated with flower development (FT, LFY, SOC1, SVP) and those involved in petaloid-anther (MADS-box family members AP1, AGL8) exhibited significant differences. These results elucidated the regulatory effects of gibberellins and their inhibitors on anther development via the GA pathway in C. oleifera, which provides a foundation for further investigation into the mechanism of flower development.
赤霉素（GAs）在调节生殖发育尤其是花发育过程中发挥着重要作用。然而，油茶花芽发育过程中GA代谢及GA信号转导相关基因的调控机制尚未完全明确。本研究以6年生油茶‘华硕’为试验材料，通过施加外源GA以及GA生物合成抑制剂矮壮素（CCC）和烯效唑（UCZ），研究不同处理下的花发育情况、GA水平、GA代谢以及GA信号转导相关基因的表达。结果表明，外源GA促进了花芽生长并加速开花，在盛花期花瓣状花药转化率高达64.11%。细胞学分析显示，GA处理的花朵在喷施后30天花药出现异常纵向伸长，并逐渐发育成花瓣状花药。KEGG分析表明，GA处理调控了植物激素信号转导。在赤霉素信号转导途径差异表达基因中，编码DELLA蛋白的基因占比最大（52.45%）。在花发育早期，GA通过调控赤霉素生物合成基因CoGA20ox1提高了赤霉素含量，且GID1对GA也有显著响应。此外，与花发育相关的基因（FT、LFY、SOC1、SVP）以及参与花瓣状花药形成的基因（MADS-box家族成员AP1、AGL8）的表达均表现出显著差异。这些结果阐明了赤霉素及其抑制剂通过GA途径对油茶花药发育的调控作用，为进一步研究花发育机制奠定了基础。
