Biological Sciences, Nara Institute of Science and Technology, 8916-5, Takayama, Ikoma, Nara, 630-0192, Japan.
Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, 4-1-8, Honcho, Kawaguchi-shi, Saitama, 332-0012, Japan.
Plant Reprod. 2018 Mar;31(1):89-105. doi: 10.1007/s00497-017-0315-0. Epub 2017 Dec 7.
Floral meristem size is redundantly controlled by CLAVATA3, AGAMOUS , and SUPERMAN in Arabidopsis. The proper regulation of floral meristem activity is key to the formation of optimally sized flowers with a fixed number of organs. In Arabidopsis thaliana, multiple regulators determine this activity. A small secreted peptide, CLAVATA3 (CLV3), functions as an important negative regulator of stem cell activity. Two transcription factors, AGAMOUS (AG) and SUPERMAN (SUP), act in different pathways to regulate the termination of floral meristem activity. Previous research has not addressed the genetic interactions among these three genes. Here, we quantified the floral developmental stage-specific phenotypic consequences of combining mutations of AG, SUP, and CLV3. Our detailed phenotypic and genetic analyses revealed that these three genes act in partially redundant pathways to coordinately modulate floral meristem sizes in a spatial and temporal manner. Analyses of the ag sup clv3 triple mutant, which developed a mass of undifferentiated cells in its flowers, allowed us to identify downstream targets of AG with roles in reproductive development and in the termination of floral meristem activity. Our study highlights the role of AG in repressing genes that are expressed in organ initial cells to control floral meristem activity.
在拟南芥中，花分生组织大小由 CLAVATA3、AGAMOUS 和 SUPERMAN 冗余控制。花分生组织活性的适当调节是形成具有固定器官数量的最佳大小花朵的关键。在拟南芥中，多个调节剂决定了这种活性。一种小的分泌肽 CLAVATA3 (CLV3) 作为干细胞活性的重要负调节剂发挥作用。两个转录因子，AGAMOUS (AG) 和 SUPERMAN (SUP)，在不同的途径中起作用，以调节花分生组织活性的终止。以前的研究没有解决这三个基因之间的遗传相互作用。在这里，我们量化了 AG、SUP 和 CLV3 突变组合在花分生组织大小方面的特定表型结果。我们详细的表型和遗传分析表明，这三个基因以部分冗余的途径协同作用，以时空方式协调调节花分生组织的大小。对 ag sup clv3 三重突变体的分析表明，该突变体在其花朵中产生了大量未分化的细胞，这使我们能够鉴定出在生殖发育和花分生组织活性终止中起作用的 AG 的下游靶标。我们的研究强调了 AG 在抑制那些在器官起始细胞中表达的基因以控制花分生组织活性方面的作用。
