Role of ubiquitin in plant cell death

植物中的程序性细胞死亡至少在三种情况下发生。首先，维管组织的形成等发育过程利用细胞死亡来塑造植物组织。其次，对病原体的防御经常涉及超敏反应，这是一种快速的程序性细胞死亡形式。第三，衰老形式的细胞程序性死亡有助于将养分从较老的植物部分转移到生长部分和种子中。所有这些过程都不完全被理解，控制它们的诱导和范围将给农业带来直接的好处。泛素蛋白酶体途径是破坏真核细胞中不需要的蛋白质的主要途径。在动物中，该途径在调节程序性细胞死亡方面起着关键作用。我们以前已经证明，该途径也参与植物细胞死亡过程。在这一应用中，我们建议利用我们前期工作中开发的突变体和检测系统，在分子水平上研究泛素和植物细胞死亡之间的联系。

Programmed cell death in plants occurs in at least three contexts. Firstly, developmental processes such as formation of vascular tissue employ cell death to shape plant tissues. Secondly, defense against pathogens frequently involves the hypersensitive response, a rapid form of programmed cell death. Thirdly, programmed cell death in the form of senescence serves to mobilize nutrients from older plant parts to growing parts and to seeds. All of these processes are incompletely understood, and manipulation of their induction and extent would provide immediate benefits to agriculture. The ubiquitin proteasome pathway is the major route for destruction of unwanted proteins in the eukaryotic cell. In animals, the pathway has a pivotal role in regulating programmed cell death. We have previously demonstrated that the pathway is also involved in plant cell death processes. In this application, we propose to investigate connections between ubiquitin and plant cell death at the molecular level, using mutants and assay systems developed in our preliminary work.