Molecular Genetic Analysis of Phase Change in Maize and Arabidopsis

玉米和拟南芥相变的分子遗传学分析

• 批准号: 9728733
• 负责人: R. Poethig
• 金额: --
• 依托单位: University of Pennsylvania
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-03-01 至 2001-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9728733&HistoricalAwards=false
• 关键词: Molecular; Genetic; Analysis; Phase; Change

Leaves produced during the juvenile and adult phases of shoot development in maize are morphologically, anatomically, and biochemically distinct. Loss-of-function mutations of GLOSSY15 (GL15) cause the epidermis of some juvenile leaves (leaves 3 to 6) to acquire adult characteristics, implying that GL15 normally functions both to promote the expression of juvenile epidermal traits and to repress the expression of adult traits. GL15 is the only gene involved in the regulation of phase-specific differences in leaf morphology that has been cloned. As such, it is useful not only as a molecular marker for phase-specific cell identity in maize, but also as an entry point into the molecular mechanism of this poorly understood phenomenon. The research proposed here will provide the basic information about GL15 necessary for understanding the function of this gene and the way in which its expression is regulated. The expression pattern of GL15 will be examined by in situ analysis of mRNA at different stages of leaf development, and at different stages during the growth of the shoot. This expression analysis will also be conducted on mutations that affect phase change (gef, Tpl, Tp2 and Tp3, dl, vp8) to determine if the effect of these mutations on epidermal identity is mediated by changes in the amount or expression pattern of GL15 mRNA. Other members of this gene family will be cloned, their genomic structure and expression pattern will be characterized, and their function will be determined by isolating Mutator insertions that disrupt their expression. In parallel with this analysis of GL15-1ike genes, Dr. Poethig will conduct a screen for genes that may be functionally redundant with GL15 by screening for mutations that affect the identity of leaves one and two in a gll5-H mutant background. Finally, Dr. Poethig will determine the function of GL15 in Arabidopsis by cloning the orthologue of GL15 in this species and determining its loss-of-function phenotype.

在玉米芽发育的幼体和成人阶段产生的叶子在形态上，解剖学和生化上是不同的。光滑15（GL15）的功能丧失突变导致某些少年叶（叶3至6）的表皮获得成人特征，这表明GL15通常起作用，既起作用既促进幼年表皮性状的表达又是抑制成人表达的表达特质。 GL15是唯一与已克隆的叶片形态相特异性差异有关的基因。因此，它不仅可以作为玉米相特异性细胞同一性的分子标记，而且还可以作为对这种鲜为人知的现象的分子机制的切入点。这里提出的研究将提供有关理解该基因功能及其表达方式的基本信息。 GL15的表达模式将通过对叶片发育的不同阶段的原位分析以及在芽生长期间在不同阶段进行的原位分析。该表达分析还将对影响相变的突变进行（GEF，TPL，TP2和TP3，DL，VP8），以确定这些突变对表皮身份的影响是否通过GL15 mRNA的量或表达模式的变化介导。该基因家族的其他成员将被克隆，它们的基因组结构和表达模式将被表征，并且它们的功能将通过隔离突变插入破坏其表达的突变器插入来确定。与对GL15-1型基因的分析同时，Poethig博士将通过筛选影响GLL5-H突变体背景中叶子一和第二的突变，对GL15进行功能冗余的基因进行筛选。最后，Poethig博士将通过克隆该物种中GL15的直系同源物并确定其功能丧失表型来确定GL15在拟南芥中的功能。