SEUSS, a member of a novel family of plant regulatory proteins, represses floral homeotic gene expression with LEUNIG.
SEUSS, a member of a novel family of plant regulatory proteins, represses floral homeotic gene expression with LEUNIG.
复制标题
DOI：
--
复制
发表时间：
2002
期刊：
影响因子：
4.6
通讯作者：
R. Franks;Chunxin Wang;J. Levin;Zhongchi Liu
中科院分区：
文献类型：
--
作者：
R. Franks;Chunxin Wang;J. Levin;Zhongchi Liu
同源异型基因表达的正确调控对于动植物发育过程中的模式形成至关重要。负调控机制确保花同源异型基因AGAMOUS仅在拟南芥花分生组织的中心表达，以指定雄蕊和心皮身份并抑制花分生组织的进一步增殖。我们报告了一个新基因SEUSS的遗传鉴定和特征，该基因是AGAMOUS负调控所必需的。SEUSS突变导致AGAMOUS mRNA的异位和早熟表达，导致外部两轮花器官的部分同源异型转化。Seuss突变的影响在与先前鉴定的AGAMOUS阻遏物LEUNIG突变结合时最为显著。在苏氏双突变体中观察到花器官的更完全的同源异型转化和所有花轮的器官损失的更大程度。通过原位杂交和双突变和三突变分析，我们发现这种增强的缺陷是由增强的异位和早熟的AGAMOUS表达引起的。使用基于地图的方法，我们分离的SEUSS基因，并表明它编码一种新的蛋白质，至少有两个谷氨酰胺丰富的结构域和一个高度保守的结构域，该结构域与动物中的LIM结构域结合转录辅助调节因子的二聚化结构域具有序列同一性。基于这些分子和遗传分析，我们提出SEUSS编码AGAMOUS的调节因子，并与LEUNIG一起发挥作用。
Proper regulation of homeotic gene expression is critical for pattern formation during both animal and plant development. A negative regulatory mechanism ensures that the floral homeotic gene AGAMOUS is only expressed in the center of an Arabidopsis floral meristem to specify stamen and carpel identity and to repress further proliferation of the floral meristem. We report the genetic identification and characterization of a novel gene, SEUSS, that is required in the negative regulation of AGAMOUS. Mutations in SEUSS cause ectopic and precocious expression of AGAMOUS mRNA, leading to partial homeotic transformation of floral organs in the outer two whorls. The effects of seuss mutations are most striking when combined with mutations in LEUNIG, a previously identified repressor of AGAMOUS. More complete homeotic transformation of floral organs and a greater extent of organ loss in all floral whorls were observed in the seuss leunig double mutants. By in situ hybridization and double and triple mutant analyses, we showed that this enhanced defect was caused by an enhanced ectopic and precocious expression of AGAMOUS. Using a map-based approach, we isolated the SEUSS gene and showed that it encodes a novel protein with at least two glutamine-rich domains and a highly conserved domain that shares sequence identity with the dimerization domain of the LIM-domain-binding transcription co-regulators in animals. Based on these molecular and genetic analyses, we propose that SEUSS encodes a regulator of AGAMOUS and functions together with LEUNIG.