Plant Molecular Biology and Biotechnology Group, ARC Centre of Excellence for Integrative Legume Research, Melbourne School of Land and Environment, The University of Melbourne, Parkville, VIC, 3010, Australia.
Planta. 2011 Mar;233(3):553-60. doi: 10.1007/s00425-010-1320-9. Epub 2010 Nov 30.
The homeobox transcription factor WUSCHEL (WUS) is known to play a critical role in the maintenance of the stem cell population in shoot and floral meristems of Arabidopsis thaliana. The corresponding gene is yet to be characterized in soybean, a vital legume crop. In this study, we isolated the soybean ortholog of WUS (GmWUS) and explored its possible conserved function by in situ hybridization analysis and ectopic expression in Arabidopsis. GmWUS is expressed in the centre of soybean vegetative shoot apical meristem and floral meristem. Intriguingly, GmWUS is also found to be expressed in the incipient floral primordia before the formation of distinct floral meristem. This novel spatial expression pattern implicates GmWUS playing a role in the floral initiation process; it also raises the question of the molecular mechanism underlying the activation of GmWUS in these cells that have adopted the floral fate. Meanwhile, ectopic expression of GmWUS in Arabidopsis results in adventitious shoot and floral meristems' formation, and the disruption in floral organ patterning. These phenotypic alterations are largely consistent with the ectopic expression of Arabidopsis WUS, indicating similar function of GmWUS with its Arabidopsis counterpart. Nevertheless, our in situ hybridization analysis has revealed its spatial expression in the incipient floral primordia indicating an additional role of GmWUS in the floral initiation process.
同源盒转录因子 WUSCHEL（WUS）已知在拟南芥的茎尖和花分生组织中维持干细胞群体中发挥关键作用。相应的基因尚未在大豆中得到表征，大豆是一种重要的豆科作物。在这项研究中，我们分离了大豆的 WUS 同源基因（GmWUS），并通过原位杂交分析和在拟南芥中的异位表达来探索其可能的保守功能。GmWUS 在大豆营养茎尖分生组织和花分生组织的中心表达。有趣的是，GmWUS 也在明显的花分生组织形成之前的初始花原基中表达。这种新的空间表达模式暗示 GmWUS 在花的起始过程中发挥作用；它还提出了一个问题，即在这些已经采用花命运的细胞中，激活 GmWUS 的分子机制是什么。同时，GmWUS 在拟南芥中的异位表达导致不定芽和花分生组织的形成，以及花器官模式的破坏。这些表型改变与拟南芥 WUS 的异位表达基本一致，表明 GmWUS 与其拟南芥对应物具有相似的功能。然而，我们的原位杂交分析揭示了其在初始花原基中的空间表达，表明 GmWUS 在花的起始过程中具有额外的作用。
