Molecular analysis of two ethylene-induced cell death processes in rice (Oryza sativa L.)

细胞死亡是植物发育的内在组成部分。它可以由发育调节或由环境信号诱导。淹水的植物因缺氧而受苦。为了避免缺氧胁迫，适应良好的植物，如水稻，通过茎部根系的生长和内部空气空间（通气组织）的形成来改善氧气供应。根的生长在覆盖根原基的表皮细胞死亡之前。植物激素乙烯调节着表皮细胞的死亡和通气组织的形成。我们以前发现表皮细胞经历细胞死亡和那些没有细胞死亡的表皮细胞之间的形态学和分子差异。在当前的项目中，我们试图定义表皮细胞死亡的细胞特征和信号通路。我们将从功能上描述在死亡细胞和非死亡细胞中被发现具有不同活性的基因，重点关注决定细胞身份的基因。这些基因可能与细胞死亡和局部限制细胞死亡的能力有关。在突变体的帮助下，已经被认为对表皮细胞死亡很重要的基因将在通气组织形成中进行研究，这代表了乙烯诱导的第二次局部细胞死亡过程。这项研究的比较部分应该有助于查明乙烯导致细胞死亡的信号传导和执行中的共同和不同途径。

Cell death is an intrinsic part of plant development. It can be developmentally regulated or be induced by environmental signals. Flooded plants suffer from lack of oxygen. To avoid hypoxic stress, well adapted plants such as rice improve their oxygen supply through growth of roots at the stem and through formation of internal air spaces (aerenchyma). Growth of roots is preceded by death of epidermal cells that cover the root primordia. Epidermal cell death as well as aerenchyma formation are regulated by the plant hormone ethylene. We previously identified morphological and molecular differences between epidermal cells that undergo cell death and those that do not. In the current project we attempt to define the cellular characteristics and the signaling pathway of epidermal cell death. We will functionally characterize genes that were found to be differentially active in dying versus non-dying cells with a focus on genes which determine cell identity. Such genes may be responsible for the ability to undergo cell death and for the local confinement of cell death. With the help of mutants, genes that have been recognized as being important for epidermal cell death will be studied in aerenchyma formation, which represents a second ethylene-induced local cell death process. This comparative part of the study should help pinpoint common and diverging pathways in the signaling and execution of cell death by ethylene.