Comparative studies of the structure and development of vegetative and floral meristems in seed plants

比较发育研究的使用继续产生重要的新数据，因为形态学概念是系统学，生理学，发育和分子生物学等学科的基础。这些研究也发挥了补充作用，在我们了解植物发育的分子方面，通过连接可观察到的发育过程与特定基因的活性。提出的植物发育方法，从分子水平到整个器官，为理解形态形式的进化和多样性提供了更全面的基础。该研究计划有3个主题：1-叶作为部分芽：芽系统和复合或复杂叶的早期发展阶段之间的比较支持叶表现出部分芽特征的想法。拟议的项目包括：i）对水苋的气生和沉水解剖单叶进行比较研究，并辅之以原位杂交技术，以探测与维持芽的不确定生长状态有关的基因的活性; ii）继续对具有多级分枝的叶的物种进行比较研究。2-天南星科的花器官特性：有些拟花蔷薇花序的特点是在单性雄花区（上）和雌花区（下）之间有一个两性花区。这些两性花代表了一个独特的情况，其中一些女性器官被男性器官取代的1轮。项目包括：i）确定一种类型的花器官被另一种类型的花器官取代的关系; ii）在早期发育期间探索花器官身份基因的活性，以与模式物种进行比较。本计画将以“真实的时间”捕捉并描述东方白色雪松幼苗叶片排列的不连续转变，作为进一步了解这些转变所涉及的机制。将开发一种组织培养技术，以“真实的时间”观察发育情况。

The use of comparative developmental studies continues to yield important new data because morphological concepts are basic to disciplines such as systematics, physiology, developmental, and molecular biology. These studies also play a complementary role in our understanding of the molecular aspects of plant development by linking observable developmental processes with the activity of specific genes. The proposed approach to plant development, ranging from the molecular level to the whole organ, provides a more comprehensive basis for understanding the evolution and diversity of morphological forms. This program of research has 3 themes: 1- Leaves as partial shoots: Comparisons between early stages of development of a shoot system and compound or complex leaves support to idea that leaves exhibit partial shoot features. Proposed projects include: i) a comparative study of aerial and submerged dissected simple leaves of Water Milfoil complemented with the use of a technique known as in situ hybridization to probe for the activity of genes involved in maintaining an indeterminate state of growth in shoots; ii) the continuation of a comparative study of species with leaves that have multiple levels of branching.2- Floral organ identity in Araceae: Some Aroids have inflorescences characterized by a zone of bisexual flowers between unisexual male (top) and female (bottom) zones. These bisexual flowers represent a unique case where some female organs are replaced by male organs on 1 whorl. Projects include: i) determining the relationships that characterize the substitution of one type of floral organ by another; ii) probing for the activity of floral organ identity genes during early development for comparison with model species.3- Variations in phyllotaxy during development: This project will capture and characterize discontinuous transitions in leaf arrangement in seedlings of Eastern White Cedar in 'real time' as a further step toward understanding the mechanisms involved in these transitions. A tissue culture technique will be developed to look at development in 'real time'.