Cell Death Processes during Expression of Hybrid Lethality in Interspecific F1 Hybrid between Nicotiana gossei Domin and Nicotiana tabacum
Cell Death Processes during Expression of Hybrid Lethality in Interspecific F1 Hybrid between Nicotiana gossei Domin and Nicotiana tabacum
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DOI：
10.1104/pp.006023
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发表时间：
2002-12
期刊：
影响因子：
7.4
通讯作者：
M. Mino;K. Maekawa;K. Ogawa;H. Yamagishi;M. Inoue
中科院分区：
文献类型：
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作者：
M. Mino;K. Maekawa;K. Ogawa;H. Yamagishi;M. Inoue
杂种致死性是生殖隔离的一种，是种间杂种苗期出现的遗传控制事件。我们使用生长速率、组织和细胞的微观特征、离子泄漏、DNA 降解、活性氧中间体（包括超氧自由基 (O2 -) 和过氧化氢 (H2O2)）以及应激反应标记基因的表达等多个性状，描述了来自 Nicotiana gosseiDomin 和 Nicotiana tabacum cv Bright-Yellow 4 的 F1 杂交幼苗的致死率。致死症状出现在发芽后4天，在26°C下生长的植物的基部下胚轴中，并延伸到下胚轴和根部。显微镜分析显示细胞死亡期间细胞成分迅速裂解。在致死后期发现膜破裂和DNA降解。子叶中叶肉细胞的死亡是由维管束引发的，这表明诱导细胞死亡的假定因素从维管组织扩散到周围细胞中。相比之下，在 37°C 下生长的植物中没有观察到这些症状。在 26°C 下生长的幼苗在下胚轴中比在 37°C 下生长的幼苗产生更多量的活性氧中间体。许多应激反应标记基因在 26°C 下表达，但在 37°C 下不表达。我们提出，一种假定的死亡因子通过维管系统进行系统性移动，引起细胞细胞质的迅速和连续的裂解，并且大量细胞死亡最终导致杂交植物的损失。
Hybrid lethality, a type of reproductive isolation, is a genetically controlled event appearing at the seedling stage in interspecific hybrids. We characterized the lethality of F1hybrid seedlings from Nicotiana gosseiDomin and Nicotiana tabacum cv Bright-Yellow 4 using a number of traits including growth rate, microscopic features of tissues and cells, ion leakage, DNA degradation, reactive oxygen intermediates including superoxide radical (O2 −) and hydrogen peroxide (H2O2), and expression of stress response marker genes. Lethal symptoms appeared at 4 d after germination in the basal hypocotyl and extended toward both the hypocotyl and root of the plants grown at 26°C. Microscopic analysis revealed a prompt lysis of cell components during cell death. Membrane disruption and DNA degradation were found in the advanced stage of the lethality. The death of mesophyll cells in the cotyledon was initiated by the vascular bundle, suggesting that a putative factor inducing cell death diffused into surrounding cells from the vascular tissue. In contrast, these symptoms were not observed in the plants grown at 37°C. Seedlings grown at 26°C generated larger amounts of reactive oxygen intermediate in the hypocotyl than those grown at 37°C. A number of stress response marker genes were expressed at 26°C but not at 37°C. We proposed that a putative death factor moving systemically through the vascular system induced a prompt and successive lysis of the cytoplasm of cells and that massive cell death eventually led to the loss of the hybrid plant.