Vasil V, Marcotte W R, Rosenkrans L, Cocciolone S M, Vasil I K, Quatrano R S, McCarty D R
Horticultural Sciences Department, University of Florida, Gainesville 32611.
Plant Cell. 1995 Sep;7(9):1511-8. doi: 10.1105/tpc.7.9.1511.
The relationship between promoter sequences that mediate Viviparous1 (VP1) transactivation and regulation by abscisic acid (ABA) in the wheat Em promoter was investigated using deletion analysis and directed mutagenesis. The Em1a G-box is strongly coupled to VP1 transactivation as well as to ABA regulation; however, the Em promoter includes additional components that can support VP1 transactivation without ABA responsiveness or synergism. Oligonucleotide tetramers of several G-box sequences, including Em1a, Em1b, and the dyad G-box element from the UV light-regulated parsley chalcone synthase gene, were sufficient to confer VP1 transactivation and the synergistic interaction with ABA to the -45 cauliflower mosaic virus 35S core promoter. These data suggest that VP1 can activate transcription through at least two classes of cis-acting sequences, including the G-box elements and the Sph regulatory motif found in the C1 promoter. The contrasting roles of these motifs in the Em and C1 promoters suggest a basis for the differential regulation of the corresponding genes by VP1.
利用缺失分析和定点诱变技术，研究了小麦Em启动子中介导胎萌1（VP1）反式激活及脱落酸（ABA）调控的启动子序列之间的关系。Em1a G盒与VP1反式激活以及ABA调控紧密相关；然而，Em启动子还包含其他元件，这些元件能够在没有ABA响应性或协同作用的情况下支持VP1反式激活。几个G盒序列的寡核苷酸四聚体，包括Em1a、Em1b以及来自紫外线调控的欧芹查尔酮合酶基因的二元G盒元件，足以赋予-45花椰菜花叶病毒35S核心启动子VP1反式激活能力以及与ABA的协同相互作用。这些数据表明，VP1可以通过至少两类顺式作用序列激活转录，包括G盒元件和在C1启动子中发现的Sph调控基序。这些基序在Em和C1启动子中的不同作用为VP1对相应基因的差异调控提供了依据。
