Characterization of Arabidopsis Thaliana Shoot Meristem L1 Layer-specific Homeodomain Protein, ATML1, and its Role in Meristem Function and Pattern Formation

拟南芥芽分生组织 L1 层特异性同源域蛋白 ATML1 的表征及其在分生组织功能和模式形成中的作用

• 批准号: 9817268
• 负责人: Sharman O'Neill
• 金额: $ 9万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-03-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9817268&HistoricalAwards=false
• 关键词: Characterization; Arabidopsis; Thaliana; Shoot; Meristem

An emerging concept in plant developmental biology is that the geneticcontrol of patterned cell division is the key to understanding plantdevelopment. Plants depend on controlled cell divisions in order to makenew organs throughout their life cycle. Organ development in floweringplants results almost entirely from the patterned control of the number,place and plane of cell division, in conjunction with regulated andcoordinated cellular expansion. The establishment of patterned controloccurs during several major phases of plant development, namely duringembryogenesis, shoot and root development, and during inflorescence andfloral morphogenesis. A novel homeobox gene, ATML1, in Arabidopsisthaliana is expressed very early in plant development, being first detectedin the zygote, then segregated to the apical cell and later to the earlyprotoderm during asymmetric cell division. An atml1 mutant exhibits anembryo-defective phenotype, with a loss of cellular patterning. Based onits pattern of expression and its mutant phenotype, the ATML1 gene and itsprotein product are likely to play a critical role in early embryogenesis,specifically contributing to the control of pattern formation duringembryogenesis and possibly later during shoot development. This project seeks to determine the function of ATML1 in embryogenesis andSAM organization/function by characterizing the genetics and phenotype ofan atml1 mutant. The specific objectives are to use a combination ofclassical and molecular genetic approaches to study the effect of the T-DNAinsertion in the atml1 mutant line. This research will provide criticalinformation for our understanding of the basis of cell division and earlypattern formation during embryogenesis, and the specification of theidentity of an L1 cell layer in the SAM. Localization of the ATML1 geneproducts should also provide insight into current hypotheses concerningprotein trafficking and lineage versus positional information in thedetermination of pattern in plants.

植物发育生物学中的一个新兴概念是，细胞分裂模式的遗传控制是理解植物发育的关键。 植物在其整个生命周期中依靠受控的细胞分裂来制造新的器官。 开花植物的器官发育几乎完全是由细胞分裂的数量、位置和平面的模式化控制，以及受调控和协调的细胞扩张共同作用的结果。 在植物发育的几个主要阶段，即胚胎发生、芽和根的发育、花序和花的形态发生期间，模式控制点的建立。 拟南芥中一个新的同源异型盒基因ATML 1在植物发育的早期就表达，首先在合子中被检测到，然后在不对称细胞分裂过程中被分离到顶端细胞，随后被分离到早期原皮层。 atml 1突变体表现出胚胎缺陷表型，细胞图案丢失。 基于其表达模式及其突变表型，ATML 1基因及其蛋白产物可能在早期胚胎发生中起关键作用，特别是有助于控制胚胎发生过程中的模式形成，并可能在随后的芽发育过程中起作用。本研究旨在通过对atml 1突变体的遗传学和表型特征的研究，确定ATML 1在胚胎发生和SAM组织/功能中的功能。 具体的目标是使用经典和分子遗传学方法的组合来研究在atml 1突变系中插入T-DNA的效果。本研究将为我们理解胚胎发生过程中细胞分裂和早期模式形成的基础以及SAM中L1细胞层的特性提供关键信息。 ATML 1基因产物的定位也应该提供洞察目前的假说concerningprotein trafficking和lineage versus positioning information in thedetermination of pattern in plants.