Positive and Negative Mechanisms Regulating Genes in Plant Defense

基因在防御反应中的转录激活已被广泛地确立为一种主要的调控水平。然而，参与转录激活的顺式元件和反式作用因子仅在少数防御基因中得到了表征。除了正向调控外，也有证据表明在防御反应过程中基因表达受到负向调控。然而，目前只克隆了3个mRNAs负调控的基因，参与其调控的顺式元件和反式因子完全未知。这项建议的一个主要总体目标是识别和比较防御反应中涉及的基因的积极和消极调控的潜在机制。第二个主要目的是阐明中枢苯丙素和植保素分支途径基因差异表达的机制。

Transcriptional activation of genes during the defense response has been widely establish as a major level of regulation. However, the cis-elements and trans-acting factors involved in transcriptional activation have been characterized for only a few defense genes. In addition to positive regulation, there is also evidence for negative regulation of gene expression during the defense response. However, only 3 genes whose mRNAs are negatively regulated have been cloned and the cis elements and trans factors involved in their regulation are completely unknown. A major overall aim of this proposal is to identify and compare the mechanisms underlying the positive and negative regulation of genes involved in the defense response. A second major aim is to elucidate the mechanisms for the differential espression of the central phenylpropanoid and phytoalexin branch pathway genes.