Zeng Liping, Zacharaki Vasiliki, van Es Sam W, Wang Yanwei, Schmid Markus
Beijing Advanced Innovation Centre for Tree Breeding by Molecular Design, College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, People's Republic of China.
School of Grassland Science, Beijing Forestry University, Beijing 100083, People's Republic of China.
Plant Physiol. 2025 May 30;198(2). doi: 10.1093/plphys/kiaf225.
Plant growth and development are regulated by many factors, including carbohydrate availability and signaling. Trehalose 6-phosphate (T6P), which is synthesized by TREHALOSE-6-PHOSPHATE SYNTHASE 1 (TPS1), is positively associated with and functions as a signal that informs the cell about the carbohydrate status. Mutations in TPS1 negatively affect the growth and development of Arabidopsis (Arabidopsis thaliana), and complete loss-of-function alleles are embryo-lethal, which can be overcome using inducible expression of TPS1 (GVG::TPS1) during embryogenesis. Using ethyl methane sulfonate mutagenesis in combination with genome re-sequencing, we have identified several alleles in the floral regulator gene HUA2 that restore flowering in tps1-2 GVG::TPS1. Genetic analyses using an HUA2 T-DNA insertion allele, hua2-4, confirmed this finding. RNA-seq analyses demonstrated that hua2-4 has widespread effects on the tps1-2 GVG::TPS1 transcriptome, including key genes and pathways involved in regulating flowering. Higher order mutants combining tps1-2 GVG::TPS1 and hua2-4 with alleles in the key flowering time regulators FLOWERING LOCUS T (FT), SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1), and FLOWERING LOCUS C (FLC) were constructed to analyze the role of HUA2 during floral transition in tps1-2 in more detail. Our findings demonstrate that loss of HUA2 can restore flowering in tps1-2 GVG::TPS1, in part through activation of FT, with contributions from the upstream regulators SOC1 and FLC. Interestingly, we found that mutation of FLC is sufficient to induce flowering in tps1-2 GVG::TPS1. Furthermore, we observed that mutations in HUA2 modulate carbohydrate signaling and that this regulation might contribute to flowering in hua2-4 tps1-2 GVG::TPS1.
植物的生长和发育受多种因素调控,包括碳水化合物的可利用性和信号传导。由海藻糖-6-磷酸合酶1(TPS1)合成的海藻糖6-磷酸(T6P)与碳水化合物状态呈正相关,并作为一种信号告知细胞碳水化合物的状态。TPS1基因的突变会对拟南芥的生长和发育产生负面影响,而功能完全丧失的等位基因是胚胎致死的,这一问题可通过在胚胎发生过程中诱导表达TPS1(GVG::TPS1)来克服。我们利用甲基磺酸乙酯诱变结合基因组重测序,在花调控基因HUA2中鉴定出了几个等位基因,这些等位基因可恢复tps1-2 GVG::TPS1的开花能力。使用HUA2 T-DNA插入等位基因hua2-4进行的遗传分析证实了这一发现。RNA测序分析表明,hua2-4对tps1-2 GVG::TPS1的转录组有广泛影响,包括参与调控开花的关键基因和途径。构建了将tps1-2 GVG::TPS1和hua2-4与关键开花时间调控因子成花素基因T(FT)、抑制CONSTANS过表达1(SOC1)和成花素基因C(FLC)中的等位基因相结合的高阶突变体,以更详细地分析HUA2在tps1-2的花期转换过程中的作用。我们的研究结果表明,HUA2的缺失可部分通过激活FT来恢复tps1-2 GVG::TPS1的开花能力,上游调控因子SOC1和FLC也有一定作用。有趣的是,我们发现FLC的突变足以诱导tps1-2 GVG::TPS1开花。此外,我们观察到HUA2的突变会调节碳水化合物信号传导,这种调节可能有助于hua2-4 tps1-2 GVG::TPS1的开花。