Genetic Regulation of Phase Change in Maize

9506258 POETIG正确的发育时间对于正常的形态发生是至关重要的。同时，不同发育事件的相对时间的变化(异时性)可能是进化中新颖性的一个重要来源，特别是当生殖成熟的时间相对于体细胞成熟发生变化时。植物新梢的营养发育有几个或多或少的离散阶段，这些阶段可以根据各种形态和生理特性相互区分。在玉米中已经定义了大量明显的阶段特异性性状，这极大地促进了对该物种阶段转变过程的遗传和分子分析。最近，波蒂格博士发现了一种新的突变--光泽早花，它可以显著加速营养和生殖发育。突变植株在新梢发育的早期就会产生带有成体营养命运的异常叶片，而且开花也很早。尽管对木本植物的广泛研究表明，新梢的营养阶段在某种程度上与其繁殖能力有关，但全球环境基金是玉米新梢发育的这两个方面之间的第一个遗传联系。Poethig博士建议a)在分子、组织和形态水平上表征gef的表型，b)通过克隆分析来确定其细胞自主性，c)通过分析双突变来确定其与其他参与相变的基因的关系。此外，他建议对影响相变的新突变进行广泛的基因筛查。这些筛选将包括在野生型遗传背景下筛选加速营养阶段变化的突变，并在gl15-2背景下筛选增强或抑制这种部分功能突变的突变。这些实验将对植物营养成熟和生殖成熟之间的关系提供新的见解，并为未来研究植物发育的这一重要方面的机制提供必要的遗传和分子资源。***

9506258 Poethig The correct timing of events in development is critical for normal morphogenesis. At the same time, changes in the relative timing of different developmental events (heterochrony) can be an important source of novelty in evolution, particularly when the timing of reproductive maturity changes relative to somatic maturity. The vegetative development of the shoot in plants is marked by several more or less discrete phases that can be distinguished from one another on the basis of a variety of morphological and physiological traits. A large number of obvious phase specific traits have been defined in maize, greatly facilitating the genetic and molecular analysis of the process of phase change in this species. Recently, Dr. Poethig has identified a new mutation, glossy early flowering, that dramatically accelerates both vegetative and reproductive development. Mutant plants produce leaves with adult vegetative fates abnormally early in shoot development and also flower early. Although extensive work on woody plants has suggested that the vegetative phase of the shoot is linked in some way to its reproductive capacity, gef is the first genetic link between these two aspects of shoot development in maize. Dr. Poethig proposes to a) characterize the phenotype of gef at a molecular, histological, and morphological level, b) determine its cell autonomy by clonal analysis, and c) establish its relationship to other genes involved in phase change by analyzing double mutations. In addition, he proposes to conduct extensive genetic screens for new mutations affecting phase change. these screens will involve screening in a wild type genetic background for mutations that accelerate vegetative phase change, and screening a gl15-2 background for mutations that either enhance or suppress this partially functional mutation. These experiments should provide new insight into the relationship between vegetative and reproductive maturation in plants, and provide th e genetic and molecular resources necessary for future research on the mechanisms of this important aspect of plant development. ***