Yin Xiaoyu, Liu Ye, Zhao Hang, Su Qi, Zong Juan, Zhu Xueying, Bao Ying
School of Life Sciences, Qufu Normal University, Qufu, 273165, Shandong, China.
Biochem Genet. 2025 Feb;63(1):298-314. doi: 10.1007/s10528-024-10727-3. Epub 2024 Mar 4.
Plants have evolved sophisticated signaling networks to adjust flowering time, ensuring successful reproduction. Two crucial flowering regulators, FLOWERING LOCUS T (FT) and CONSTANS (CO), play pivotal roles in regulating flowering across various species. Previous studies have indicated that suppressing Gossypium hirsutum CONSTANS-LIKE 2 (GhCOL2), a homolog of Arabidopsis CO, leads to delayed flowering in cultivated cotton. However, the underlying regulatory mechanisms remain unknown. In this study, a yeast one-hybrid and dual-LUC expression assays were used to elucidate the molecular mechanism through which GhCOL2 regulates the transcription of GhHD3A. RT-qPCR was used to examine the expression of GhCOL2 and GhHD3A. Our findings reveal that GhCOL2 directly binds to CCACA cis-elements and atypical CORE (TGTGTATG) cis-elements in the promoter regions of HEADING DATE 3 A (HD3A), thereby activating GhHD3A transcription. Notably, GhCOL2 and GhHD3A exhibited high expression levels in the adult stage and low levels in the juvenile stage. Interestingly, the expression of GhCOL2 and GhHD3A varied significant between the two cotton varieties (Tx2094 and Maxxa). In summary, our study enhances the understanding of the molecular mechanism by which cotton GhCOL2-GhHD3A regulates flowering at the molecular level. Furthermore, it contributes to a broader comprehension of the GhCOL2-GhHD3A model in G. hirsutum.
植物已经进化出复杂的信号网络来调节开花时间，以确保成功繁殖。两个关键的开花调节因子，成花素（FT）和CONSTANS（CO），在调节不同物种的开花过程中起着关键作用。先前的研究表明，抑制陆地棉CONSTANS-LIKE 2（GhCOL2），即拟南芥CO的同源物，会导致栽培棉花开花延迟。然而，其潜在的调控机制仍然未知。在本研究中，利用酵母单杂交和双荧光素酶表达分析来阐明GhCOL2调控GhHD3A转录的分子机制。采用RT-qPCR检测GhCOL2和GhHD3A的表达。我们的研究结果表明，GhCOL2直接与开花时间3A（HD3A）启动子区域的CCACA顺式元件和非典型核心（TGTGTATG）顺式元件结合，从而激活GhHD3A转录。值得注意的是，GhCOL2和GhHD3A在成年期表达水平高，在幼年期表达水平低。有趣的是，GhCOL2和GhHD3A在两个棉花品种（Tx2094和Maxxa）之间的表达差异显著。总之，我们的研究增进了对棉花GhCOL2-GhHD3A在分子水平上调控开花的分子机制的理解。此外，它有助于更广泛地理解陆地棉中的GhCOL2-GhHD3A模型。
