National Key Laboratory of Crop Genetics and Germplasm Enhancement, National Center for Soybean Improvement, Nanjing Agricultural University, Nanjing, Jiangsu, 210095, China.
College of Agro-grass-land Science, Nanjing Agricultural University, Nanjing, Jiangsu, China.
BMC Genomics. 2018 Jan 16;19(1):51. doi: 10.1186/s12864-017-4402-2.
The MADS-box transcription factors are an ancient family of genes that regulate numerous physiological and biochemical processes in plants and facilitate the development of floral organs. However, the functions of most of these transcription factors in soybean remain unknown.
In this work, a MADS-box gene, GmAGL1, was overexpressed in soybean. Phenotypic analysis showed that GmAGL1 overexpression not only resulted in early maturation but also promoted flowering and affected petal development. Furthermore, the GmAGL1 was much more effective at promoting flowering under long-day conditions than under short-day conditions. Transcriptome sequencing analysis showed that before flowering, the photoperiod pathway photoreceptor CRY2 and several circadian rhythm genes, such as SPA1, were significantly down-regulated, while some other flowering-promoting circadian genes, such as GI and LHY, and downstream genes related to flower development, such as FT, LEAFY, SEP1, SEP3, FUL, and AP1, were up-regulated compared with the control. Other genes related to the flowering pathway were not noticeably affected.
The findings reported herein indicate that GmAGL1 may promote flowering mainly through the photoperiod pathway. Interestingly, while overexpression of GmAGL1 promoted plant maturity, no reduction in seed production or oil and protein contents was observed.
MADS 框转录因子是一个古老的基因家族，调节植物的许多生理和生化过程，并促进花器官的发育。然而，这些转录因子中的大多数在大豆中的功能仍不清楚。
在这项工作中，大豆中过表达了一个 MADS 框基因 GmAGL1。表型分析表明，GmAGL1 的过表达不仅导致早期成熟，而且促进开花并影响花瓣发育。此外，GmAGL1 在长日照条件下比在短日照条件下更有效地促进开花。转录组测序分析表明，在开花前，光周期途径光受体 CRY2 和几个生物钟基因，如 SPA1，显著下调，而其他一些促进开花的生物钟基因，如 GI 和 LHY，以及与花发育相关的下游基因，如 FT、LEAFY、SEP1、SEP3、FUL 和 AP1，与对照相比上调。其他与开花途径相关的基因没有明显受到影响。
本文的研究结果表明，GmAGL1 可能主要通过光周期途径促进开花。有趣的是，尽管 GmAGL1 的过表达促进了植物的成熟，但没有观察到种子产量或油和蛋白质含量的降低。
