【作者】 刘天宝；

【导师】 程备久；

【作者基本信息】 安徽农业大学 ， 生物物理学， 2010， 硕士

【摘要】 叶序是植物的叶片围绕茎有规律地排列的现象,自然界中常见的三种叶序类型是:互生、对生和轮生。研究表明,顶端分生组织(SAM)中细胞分裂素(CTK)和生长素(IAA)参与叶序的形成过程。生长素在顶端分生组织中的运输和差异化分布控制叶原基的形成,细胞分裂素通过影响SAM的大小以及调控生长素运输蛋白基因的表达影响生长素在SAM中的分布间接影响叶序的形成,同时顶端分生组织中CTK/IAA域值的稳定和变化也可能是调节叶序稳定和变异的重要因素。本研究采用酶联免疫法(ELISA)测定了多种不同叶序植物顶端分生组织细胞分裂素和生长素的含量以及部分植物顶端分生组织周围嫩茎和嫩叶细胞分裂素和生长素含量,分析了不同叶序植物内源细胞分裂素和生长素差异,获得以下主要结果:1.对供试材料不同生育期顶端分生组织中的激素含量分析显示,不同叶序植物不同生育期顶端分生组织中细胞分裂素和生长素含量及CTK/IAA值无显著差异。2.顶端分生组织中细胞分裂素及生长素含量与其周围的嫩茎和嫩叶差异无明显规律,但是顶端分生组织中CTK/IAA值显著高于周围的嫩茎和嫩叶。3.在不同科植物间,不同叶序植物顶端分生组织中激素含量及CTK/IAA值无规律可循。叶序相同的植物顶端分生组织中各类激素含量及CTK/IAA值均存在显著差异。4.在夹竹桃科内,轮生叶序的夹竹桃顶端分生组织中细胞分裂素含量及CTK/IAA值显著高于对生叶序的长春花,且三大类细胞分裂素含量均显著较高;菊科中,对生叶序的万寿菊顶端分生组织中细胞分裂素含量及CTK/IAA值显著高于互生叶序的菊花,且三大类细胞分裂素均显著较高。5.对菊芋和金鱼草的研究表明,同一植物不同叶序植株间,对生植株顶端分生组织中细胞分裂素含量及CTK/IAA值显著高于互生植株,且三大类细胞分裂素均不低于互生植株;对生植株与互生植株顶端分生组织中生长素含量差异不显著。综上所述,叶序类型与顶端分生组织中激素含量及比值之间存在密切联系。在同科或更近的亲缘关系内,有轮生植物顶端分生组织中细胞分裂素含量及CTK/IAA值显著高于对生植物,对生植物顶端分生组织中细胞分裂素含量及CTK/IAA值显著高于互生植物的趋势。顶端分生组织中细胞分裂素含量及CTK/IAA值可能是调节植物叶序变异的重要因素。更多还原

【Abstract】 Phyllotaxis is the regular arrangement of leaves or flowers around a plant stem. The most prevalent patterns are alternate, opposite and whorled patterns. The research results show that cytokinin and auxin in shoot apical meristem(SAM) participate in the process of the formation of phyllotaxis. A mechanism based on polar transport and differential distribution of auxin regulates leaf primordium formation and position on the shoot apical meristem. Cytokinin influences the formation of phyllotaxis indirectly through effecting the distribution of auxin by regulating the expression of auxin transport protein genes and the size of SAM. Meanwhile, stabilization and change of CTK/IAA value in the shoot apical meristem is an important factor that regulates phyllotaxis stabilization and variation. This study determined the contents of cytokinin and auxin in the shoot apical meristem and the tender stems and leaves around SAM by ELISA. Results obtained by analyzing the datas as follow:1. Analysis of hormone contents of plants tested show that Hormone contents and the values of CTK/IAA at different growth and development periods were not significant no matter in opposite or alternate phyllotaxis plants.2. There are no obivious regularity about the contents of cytokinin and auxin in shoot apical meristem, tender stems, and tender leaves. Nevertheless, the value of CTK/IAA in shoot apical meristem is significantly higher than that in tender stems or leaves.3. Among different families of plants, there are no obivious regularity about the contents of hormone and the values of CTK/IAA. There are significant differences of hormone contents and CTK/IAA values in the shoot apical meristems of the same phyllotaxis plants.4. In the Apocynaceae family plants, the content of CTK and value of CTK/IAA in shoot apical meristem of the whorled phyllotaxis plant Nerium indicum Mill are always higher than that of the opposite phyllotaxis plant Catharanthus roseus (L.) Don. In the Compositae family plants, the content of CTK and value of CTK/IAA in shoot apical meristem of the opposite phyllotaxis plant Tagetes erecta L. are higher than that of the alternate phyllotaxis plant Dendranthema morifolium, and three major categories of cytokinin are all significantly higher.5. Some species of plants have different phyllotaxis types, for example, Helianthus tuberosus and Antirrhinum majus may display three common types of phyllotaxis in their development process. This study show that the content of CTK and value of CTK/IAA in shoot apical meristem of individuals with opposite phyllotaxis are significantly higher than that of individuals with alternate phyllotaxis, and three major categories of cytokinin are not lower than alternate plants. The contents of auxin have no significant differences.In conclusion, this study confirms the close relation between phyllotaxis types and hormone contents or ratios in the shoot apical meristem. In the same family or closer genetic relationship of plants, it is a trend that the contents of CTK and values of CTK/IAA in SAM of whorled phyllotaxis plants are significantly higher than that of opposite phyllotaxis plants, while opposite phyllotaxis plants are singinficantly higher than alternate phyllotaxis plants. The contents of cytokinin and values of CTK/IAA in SAM may be important factors regulating plants phyllotaxis variations.更多还原