2003-08-012024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/655985摘要：大部份真雙子葉植物的花都具有兩輪不孕性的構造，較外輪者通常稱為花萼，而內輪的通常稱為花瓣。然而僅依據位置的不同而給予花被定義常常會造成一些問題，比方說有許多的植物只具有一輪花被，或是有時具有多輪花被時，其花被器官的起源就容易有許多爭議。真雙子葉植物的基群和核心真雙子葉植物的基群常有花被減少或缺失，以及形態上的特殊變異情形。這些植物在探討被子植物花的演化上因而扮演著非常重要的角色。雖然被子植物開花的控制很可能都是依循類似的系統（即floral ABC model）來調節基本的花部發育，但是在被子植物基群以及真雙子葉植物基群中，已經有發現相當程度的變異存在。先前的研究顯示，在真雙子葉植物的基群到核心真雙子葉植物的基群的演化之間有一個B群基因複製的情況發生。相對而言，在其他的被子植物中只有兩個主要的基因系被發現(paleoAP3和PI)。本計畫即利用七種在台灣可以被發現的真雙子葉植物基群植物為材料，檢視它們的B群基因的種類及結構。同時對基因表現進行分析，以對其功能有初步的瞭解。在得到DNA的序列之後，也將利用相關的基因進行譜系分析，以檢測B群基因的演化和這些物種之間的親源關係。<br> Abstract: Most of the eudicot flowers have two whorls of non-fertile reproductive organs, usually identified as sepals for the outer whorl and petals for the inner whorl. However, the definition of floral organ solely based on the positions is problematic because in some cases, flowers with only one whorl or with more than two whorls are present. The basal eudicots and basal core eudicots show highly variable floral features in terms of flower size and floral organ numbers, such as the absence of perianth in Trochodendron and size reduction in Santales flowers. These plants are critical to understand the evolutionary developmental program of perianth in flowering plants. Although the floral ABC model is general accepted as ubiquitous in flowering plants, variation in gene expression has been found in basal angiosperms and basal eudicots. Furthermore, previous studies have shown that there is a duplication event of AP3-like (B class) genes along the branch leading to core eudicot lineages. Such duplication may be responsible of the diverse floral features among basal eudicots. There are three B class lineages in core eudicots, whereas in all other angiosperms, there are only two lineages (paleoAP3 and PI) found. We will examine the B class gene evolution among the basal eudicot lineages by cloning B class genes from seven basal eudicots in Taiwan. All of the cDNA clones will be obtained from 3’RACE system with B class gene specific primers, from all floral tissues. Genomic sequences of the B class genes will be examined to reveal the exon/intron structures and promoter sequences. RT-PCR and northern blots will be performed to analyze expression patterns of the B class genes in different floral organs. Phylogenetic analysis will be performed to clarify the genealogy of B class genes and the relationships of basal eudicots.真雙子葉植物基群花被演化B群基因演化basal eudicotsperianth evolutionB class gene evolution