Functional Analysis of the Viviparous-1 Gene of Maize

在这篇论文中，McCarty博士探讨了控制和整合玉米种子成熟相关的多种发育反应表达的调控机制。Viviparous-1 （Vp-1）基因的突变阻断了胚胎和发育中的种子糊粉组织中大部分或全部成熟相关基因的表达。Vp1调控两组看似无关的基因：1)胚胎成熟集，包括各种胚胎发育晚期丰富基因（LEA's）和7s球蛋白基因。这些基因也受脱落酸激素的调节。2)第二组包括花青素通路的基因。麦卡蒂博士已经证明，Vp1通过激活第二个调控基因C1来激活花青素途径。因此，这些基因起着调节等级的作用。他的研究结果表明Vp1是一种新的转录因子。通过在玉米原生质体中表达Vp1基因，他能够表征参与小麦LEA基因C1和Em调控的调控序列。该系统还提供了Vp-1蛋白的功能测定。他的目标是1)确定Vp-1如何调节靶基因的转录，2)使用诱变技术确定Vp1蛋白中功能重要的序列，3)确定与Vp1相互作用的因子，4)利用异位表达表征Vp1在发育中的作用，5)表征Vp-1表达的转录和转录后调控。

In this proposal Dr. McCarty explores the regulatory mechanism which controls and integrates expression of diverse developmental responses related to seed maturation in maize. Mutations in the Viviparous-1 (Vp-1) gene block much or all of maturation related gene expression in embryo and aleurone tissues of the developing seed. Two seemingly unrelated groups of genes are regulated by Vp1: 1) An embryo maturation set including various late embryogenesis abundant genes (LEA's) and the 7s globulin genes. These genes are also regulated by the hormone, abscisic acid. 2) The second set includes the genes of the anthocyanin pathway. Dr. McCarty has shown that Vp1 activates the anthocyanin pathway by activating a second regulatory gene, C1. Thus, these genes function as a regulatory hierarchy. His results suggest that Vp1 is a novel transcription factor. By expressing the Vp1 gene in maize protoplasts, he is able to characterize regulatory sequences involved in regulation of C1 and Em, a LEA gene of wheat. This system also provides a functional assay for the Vp-1 protein. His objectives are to 1) Determine how Vp-1 regulates transcription of target genes, 2) Use mutagenesis to define functionally important sequences in the Vp1 protein, 3) Identify factors that interact with Vp1, 4) Characterize Vp1's role in development using ectopic expression and 5) Characterize transcriptional and post-transcriptional regulation of Vp-1 expression.