Department of Biological Sciences, Seoul National University, Seoul 151-742, Republic of Korea.
J Exp Bot. 2011 Aug;62(13):4571-81. doi: 10.1093/jxb/err168. Epub 2011 May 30.
In Arabidopsis, inflorescence stem formation is a critical process in phase transition from the vegetative to the reproductive state. Although inflorescence stem development has been reported to depend on the expression of a variety of genes during floral induction and repression, little is known about the molecular mechanisms involved in the control of inflorescence stem formation. By activation T-DNA tagging mutagenesis of Arabidopsis, a dominant gain-of-function mutation, eve1-D (eternally vegetative phase1-Dominant), which has lost the ability to form an inflorescence stem, was isolated. The eve1-D mutation exhibited a dome-shaped primary shoot apical meristem (SAM) in the early vegetative stage, similar to that seen in the wild-type SAM. However, the SAM in the eve1-D mutation failed to transition into an inflorescence meristem (IM) and eventually reached senescence without ever leaving the vegetative phase. The eve1-D mutation also displayed pleiotropic phenotypes, including lobed and wavy rosette leaves, short petioles, and an increased number of rosette leaves. Genetic analysis indicated that the genomic location of the EVE1 gene in Arabidopsis thaliana corresponded to a bacterial artificial chromosome (BAC) F4C21 from chromosome IV at ∼17cM which encoded a novel ubiquitin family protein (At4g03350), consisting of a single exon. The EVE1 protein is composed of 263 amino acids, contains a 52 amino acid ubiquitin domain, and has no glycine residue related to ubiquitin activity at the C-terminus. The eve1-D mutation provides a way to study the regulatory mechanisms that control phase transition from the vegetative to the reproductive state.
在拟南芥中，花序茎的形成是从营养生长到生殖生长的关键过程。尽管已经报道花序茎的发育依赖于在花诱导和抑制期间表达的各种基因，但对控制花序茎形成的分子机制知之甚少。通过对拟南芥的激活 T-DNA 标签诱变，分离到一个显性获得性功能突变体 eve1-D（永远的营养生长阶段 1-显性），它失去了形成花序茎的能力。eve1-D 突变体在早期营养生长阶段表现出圆顶状的主茎分生组织（SAM），类似于野生型 SAM。然而，eve1-D 突变体的 SAM 未能转变为花序分生组织（IM），最终在没有离开营养生长阶段的情况下衰老。eve1-D 突变体还表现出多种表型，包括裂片和波浪状的莲座叶、短叶柄和增加的莲座叶数量。遗传分析表明，拟南芥 EVE1 基因的基因组位置对应于染色体 IV 上的细菌人工染色体（BAC）F4C21，位于约 17cM 处，编码一种新的泛素家族蛋白（At4g03350），由一个单外显子组成。EVE1 蛋白由 263 个氨基酸组成，含有 52 个氨基酸的泛素结构域，C 末端没有与泛素活性相关的甘氨酸残基。eve1-D 突变体为研究从营养生长到生殖生长的状态转变的调控机制提供了一种方法。
