RUI: Specification of Meristem Identity in Pea Inflorescences

不同的被子植物花序模式可以归因于一些基本计划的修改。 这些修饰中的一些影响指定花序（I）和花（F）分生组织身份的基因。 拟南芥中LEAFY基因和金鱼草中FLORICAlidae基因的突变阻断或延迟了I到F的转换，使得末端（I-1）分生组织启动二级（I-2）分生组织，而不是花分生组织。 这些突变体与豌豆花序具有发育相似性，其中I-1到I-2到F的转换反映了野生型表型。 豌豆，拟南芥和金鱼草分生组织身份基因功能的比较将解决如何进化修饰可以改变花序结构。 这些实验的长期目标是建立豌豆花序发育的遗传等级。 这一建议集中在三个分生组织身份基因：（1）DET（DETATE），这被假设为一个I-1身份基因;（2）VEG（VEGETATIVE），这被认为是指定I-2和/或F分生组织身份;和（3）PIM（PROLIFERATING INFLORESCENCE MERISTEM），这似乎分配F身份。 利用这些基因的突变体，PI将探索分生组织特性基因之间的相互作用如何调节花序发育。 与其他假定的分生组织身份基因的相互作用将进行调查。 突变分生组织的图像分析将用于确定分生组织身份基因的表达和分生组织几何形状是否相关。 最后，克隆的拟南芥和金鱼草分生组织同一性基因将被用于鉴定豌豆中的同源RFLP（限制性片段长度多态性）序列。 这些RFLPs将被映射和测试与遗传鉴定的豌豆分生组织身份基因的连锁。 通过用金鱼草属和农杆菌属分生组织同一性基因转化豌豆分生组织同一性突变体，将进一步检验同源性。 共同提出的遗传，形态学和分子实验将确定是否（以及如何）相似的基因可以产生两个I到F和I-1到I-2到F花序模式。

Diverse angiosperm inflorescence patterns can be attributed to modifications of a few basic plans. Some of these modifications affect genes specifying inflorescence (I) and floral (F) meristem identity. Mutations of the LEAFY gene in Arabidopsis and the FLORICAULA gene in Antirrhinum block or delay the I to F transition so that the terminal (I-1) meristem initiates second order (I-2) meristems rather than floral meristems. These mutants have developmental parallels to Pisum sativum inflorescences where I-1 to I-2 to F transitions reflect the wild type phenotype. A comparison of meristem identity gene function in Pisum, Arabidopsis, and Antirrhinum will address how evolutionary modifications can alter inflorescence architecture. The long term goal of these experiments is to establish the genetic hierarchy regulating inflorescence development in Pisum. This proposal focuses on three meristem identity genes: (1) DET (DETERMINATE), which is hypothesized to be an I-1 identity gene; (2) VEG (VEGETATIVE), which is thought to specify I-2 and/or F meristem identity; and (3) PIM (PROLIFERATING INFLORESCENCE MERISTEM), which appears to assign F identity. Using mutants of these genes, the PI will explore how interactions between meristem identity genes regulate inflorescence deelopment. Interactions with other putative meristem identity genes will be investigated. Image analysis of mutant meristems will be used to ascertain if expression of meristem identity genes and meristem geometry correlate. Finally, cloned Arabidopsis and Antirrhinum meristem identity genes will be used to identify homologous RFLP (restriction fragment length polymorphisms) sequences in Pisum. These RFLPs will be mapped and tested for linkage with genetically identified Pisum meristem identity genes. Homology will be further tested by transformation of Pisum meristem identity mutants with Antirrhinum and Agrobacterium meristem identity genes. Together the proposed genetic, morphological, a nd molecular experiments will ascertain if (and how) similar genes can give rise to both I to F and I-1 to I-2 to F inflorescence patterns.