Gansu Provincial Key Laboratory of Aridland Crop Science, College of Life Science and Technology, Gansu Agricultural University, Lanzhou, 730070, China.
Cotton Research Institute, Xinjiang Academy of Agricultural and Reclamation Science, Shihezi, 832000, China.
Plant Cell Rep. 2024 Jun 13;43(7):170. doi: 10.1007/s00299-024-03252-5.
The silencing of GhGASA14 and the identification of superior allelic variation in its coding region indicate that GhGASA14 may positively regulate flowering and the response to GA. Gibberellic acid-stimulated Arabidopsis (GASA), a member of the gibberellin-regulated short amino acid family, has been extensively investigated in several plant species and found to be critical for plant growth and development. However, research on this topic in cotton has been limited. In this study, we identified 38 GhGASAs that were dispersed across 18 chromosomes in upland cotton, and all of these genes had a GASA core domain. Transcriptome expression patterns and qRT-PCR results revealed that GhGASA9 and GhGASA14 exhibited upregulated expression not only in the floral organs but also in the leaves of early-maturing cultivars. The two genes were functionally characterized by virus-induced gene silencing (VIGS), and the budding and flowering times after silencing the target genes were later than those of the control (TRV:00). Compared with that in the water-treated group (MOCK), the flowering period of the different fruiting branches in the GA-treated group was more concentrated. Interestingly, allelic variation was detected in the coding sequence of GhGASA14 between early-maturing and late-maturing accessions, and the frequency of this favorable allele was greater in high-latitude cotton cultivars than in low-latitude ones. Additionally, a significant linear relationship was observed between the expression level of GhGASA14 and flowering time among the 12 upland cotton accessions. Taken together, these results indicated that GhGASA14 may positively regulate flowering time and respond to GA. These findings could lead to the use of valuable genetic resources for breeding early-maturing cotton cultivars in the future.
GhGASA14 的沉默和其编码区优异等位基因变异的鉴定表明，GhGASA14 可能正向调控开花和对 GA 的响应。赤霉素刺激的拟南芥（GASA）是赤霉素调节的短氨基酸家族的一员，在几种植物物种中得到了广泛研究，发现其对植物生长和发育至关重要。然而，在棉花中对此课题的研究还很有限。在这项研究中，我们在陆地棉中鉴定了 38 个 GhGASAs，它们分布在 18 条染色体上，所有这些基因都具有 GASA 核心结构域。转录组表达模式和 qRT-PCR 结果表明，GhGASA9 和 GhGASA14 在花器官中不仅表达上调，而且在早熟品种的叶片中也表达上调。通过病毒诱导的基因沉默（VIGS）对这两个基因进行了功能表征，沉默靶基因后，萌芽和开花时间比对照（TRV：00）晚。与水处理组（MOCK）相比，GA 处理组不同结果枝的开花期更加集中。有趣的是，在早熟和晚熟品种之间检测到 GhGASA14 编码序列中的等位基因变异，高纬棉品种中这种有利等位基因的频率高于低纬棉品种。此外，在 12 个陆地棉品种中，GhGASA14 的表达水平与开花时间之间存在显著的线性关系。综上所述，这些结果表明 GhGASA14 可能正向调控开花时间并响应 GA。这些发现可能为未来培育早熟棉花品种利用有价值的遗传资源提供依据。
