Menzel G, Apel K, Melzer S
Swiss Federal Institute of Technology, Institute for Plant Sciences, Zürich, Switzerland.
Plant J. 1996 Mar;9(3):399-408. doi: 10.1046/j.1365-313x.1996.09030399.x.
To understand the molecular mechanisms involved in the transition from vegetative to reproductive growth, the photoperiodic-controlled induction of flowering in the long-day plant Sinapis alba was used to screen for regulatory genes which are expressed upon induction in the apical meristem. By using the conserved MADS box-encoding region of the organ identity gene AGAMOUS, the genes SaMADS A and SaMADS B were identified which are expressed in transition stages of mustard. RNA blot analysis has confirmed that the transcript levels of both genes are drastically increased shortly after the induction of flowering and that both genes are expressed earlier than the known MADS box genes. In situ hybridization studies have shown that the expression of the genes is restricted to the apical meristem of induced plants during early phases of reproductive development. The expression of SaMADS A is first detectable in the central zone of the meristem, a region where the earliest changes of an evoked meristem could be detected by classical physiological methods, suggesting that SaMADS A may have an important function during the transition to flowering.
为了了解从营养生长向生殖生长转变所涉及的分子机制，利用长日照植物白芥中光周期控制的开花诱导来筛选在顶端分生组织诱导时表达的调控基因。通过使用器官特征基因AGAMOUS的保守MADS盒编码区，鉴定出了在芥菜转变阶段表达的基因SaMADS A和SaMADS B。RNA印迹分析证实，开花诱导后不久，这两个基因的转录水平急剧增加，并且这两个基因的表达都早于已知的MADS盒基因。原位杂交研究表明，在生殖发育早期，这些基因的表达仅限于诱导植物的顶端分生组织。SaMADS A的表达最早在分生组织的中央区域被检测到，这是一个通过经典生理学方法可以检测到诱发分生组织最早变化的区域，这表明SaMADS A在向开花转变过程中可能具有重要功能。
