Wei Qian, Ma Chao, Xu Yanjie, Wang Tianle, Chen Yiyu, Lü Jing, Zhang Lili, Jiang Cai-Zhong, Hong Bo, Gao Junping
Beijing Key Laboratory of Development and Quality Control of Ornamental Crops, Department of Ornamental Horticulture, China Agricultural University, Beijing, 100193, China.
Crops Pathology and Genetic Research Unit, United States Department of Agriculture, Agricultural Research Service, Davis, CA, 95616, USA.
Nat Commun. 2017 Oct 10;8(1):829. doi: 10.1038/s41467-017-00812-0.
Age, as a threshold of floral competence acquisition, prevents precocious flowering when there is insufficient biomass, and ensures flowering independent of environmental conditions; however, the underlying regulatory mechanisms are largely unknown. In this study, silencing the expression of a nuclear factor gene, CmNF-YB8, from the short day plant chrysanthemum (Chrysanthemum morifolium), results in precocious transition from juvenile to adult, as well as early flowering, regardless of day length conditions. The expression of SQUAMOSA PROMOTER BINDING-LIKE (SPL) family members, SPL3, SPL5, and SPL9, is upregulated in CmNF-YB8-RNAi plants, while expression of the microRNA, cmo-MIR156, is downregulated. In addition, CmNF-YB8 is shown to bind to the promoter of the cmo-MIR156 gene. Ectopic expression of cmo-miR156, using a virus-based microRNA expression system, restores the early flowering phenotype caused by CmNF-YB8 silencing. These results show that CmNF-YB8 influences flowering time through directly regulating the expression of cmo-MIR156 in the aging pathway.The mechanisms by which plant age regulates flowering remain incompletely understood. Here the authors show that age dependent regulation of SPL transcription factors by miR156 influence flowering via control of NF-YB8 expression in Chrysanthemum.
年龄作为获得成花能力的一个阈值，在生物量不足时可防止过早开花，并确保开花不受环境条件影响；然而，其潜在的调控机制在很大程度上尚不清楚。在本研究中，沉默短日植物菊花（Chrysanthemum morifolium）中的一个核因子基因CmNF-YB8的表达，会导致植株早熟，从幼年阶段过渡到成年阶段，并且不论日照长度条件如何都会提前开花。在CmNF-YB8-RNAi植株中，SQUAMOSA启动子结合蛋白样（SPL）家族成员SPL3、SPL5和SPL9的表达上调，而微小RNA cmo-MIR156的表达下调。此外，研究表明CmNF-YB8可与cmo-MIR156基因的启动子结合。利用基于病毒的微小RNA表达系统异位表达cmo-miR156，可恢复由CmNF-YB8沉默导致的早花表型。这些结果表明，CmNF-YB8通过在衰老途径中直接调控cmo-MIR156的表达来影响开花时间。植物年龄调控开花的机制仍未完全了解。本文作者表明，miR156对SPL转录因子的年龄依赖性调控通过控制菊花中NF-YB8的表达来影响开花。
