Regulation of Inflorescence and Pedicel Development in Tomato.

开花植物的枝条分生组织是一个多细胞器官，为枝条的无限生长提供能力。该研究小组将通过继续我们对番茄无缝连接-1突变的研究，来调查新梢分生组织及其衍生器官中的细胞在发育过程中是如何协调的。在无接合-1突变体中，花序在仅形成一到两朵花后恢复营养生长，并以活力四射的多叶枝条终止。无接合-1突变体也形成完全没有离区的花梗。因此，番茄的无缝连接-1基因参与了花序分生组织状态的维持和花梗离区的形成这两个重要的发育过程。通过对倾周嵌合体的分析发现，分生组织的内部(L3)细胞既控制花序分生组织的决定，又控制花梗离区的形成。克隆结果表明，该基因为MADS盒基因。维持花序分生组织和花梗离区发育过程中细胞协调的研究将继续进行。1.对野生型和无缝-1突变体以及6个倾周嵌合体进行原位杂交，以进一步了解花序发育和离区形成过程中细胞协调的本质。2.我们将在我们从双突变分析中发现与无缝连接-1存在遗传互作的各种突变体中检测无缝连接-1的表达模式。这类研究将更清楚地了解导致不同类型分生组织活动的这些基因的相互作用。3.野生型植株和大花萼之间将构建多组倾周嵌合体，这是另一个同时影响离区发育和花序分生组织维持的突变，以及大花萼和无缝1之间的嵌合体。对于L3细胞所产生的信号接收过程中涉及大花瓣的假设将会得到验证，L3细胞是无缝连接-1基因的野生型。4.将对发育中的花梗进行谱系分析，以确定在野生型和无缝-1突变植物中导致该器官不同区域(近端花梗、离区和远端花梗)的细胞分裂模式。通过这些实验，应该更多地了解调控离区形成和花序发育的细胞和遗传相互作用，以阐明这两个有趣的发育过程和重要的农业过程之间的关系。

The shoot meristem of flowering plants is a multicellular organ that provides the capacity for indeterminate growth of the shoot. The research team will investigate how the cells in the shoot meristem and its derivative organs are coordinated during development by continuing our study of the jointless-1 mutation of tomato. In jointless-1 mutants, the inflorescences revert to vegetative growth after forming only one or two flowers and terminate with a vigorous, leafy shoot. jointless-1 mutants also form flower pedicels that completely lack an abscission zone. Thus, the JOINTLESS-1 gene of tomato is involved in two important developmental processes, the maintenance of the inflorescence meristem state and the formation of the pedicel abscission zone. By analyzing periclinal chimeras it was found that internal (L3) cells of the meristem control both inflorescence meristem determinacy and pedicel abscission zone formation. Cloning of JOINTLESS-1 revealed that it is a MADS box gene. The investigations of coordination of cells during the processes of maintaining the inflorescence meristem and development of pedicel abscission zones will be continued. 1. In situ hybridization will be performed using JOINTLESS-1 probes on wild-type and jointless-1 mutants and on the six periclinal chimeras to learn more about the nature of the cell coordination that occurs during inflorescence development and abscission zone formation. 2. Patterns of JOINTLESS-1 expression will be examined in various mutants that we have found to show genetic interactions with jointless-1 from double mutant analysis. Such studies will provide a clearer understanding of the interactions of these genes that result in different types of meristem activity. 3. Sets of periclinal chimeras will be constructed between wild-type plants and macrocalyx, another mutation that affects both abscission zone development and inflorescence meristem maintenance, and between macrocalyx and jointless-1. The hypothesis that macrocalyx is involved in the reception of the signal produced by L3 cells that are wild-type for the JOINTLESS -1 gene will be tested. 4. A lineage analysis will be identified for the developing pedicel to determine the patterns of cell divisions that give rise to the various regions of this organ (proximal pedicel, abscission zone, and distal pedicel) in wild-type and jointless-1 mutant plants. With these experiments more should be learned about the cellular and genetic interactions regulating abscission zone formation and inflorescence development to elucidate the relationship between these two developmentally interesting and agriculturally important processes.