French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Beer-Sheva, Israel and Midreshet Ben-Gurion, Israel.
Rejuvenation Res. 2009 Dec;12(6):435-43. doi: 10.1089/rej.2009.0887.
Dedifferentiation signifies the capacity of somatic cells to acquire stem cell-like properties. This process can be induced during normal development and as a response to various stimuli, such as pathogen infection and wounding. Dedifferentiation also characterizes the transition of differentiated leaf cells into protoplasts (plant cells devoid of cell walls), a transition accompanied by widespread chromatin decondensation. Transcriptome profiling of dedifferentiating protoplast cells revealed striking similarities with senescing cells; both display a large increase in the expression of genes of specific transcription factor (TF) families, including ANAC, WRKY, bZIP, and C2H2. Further analysis showed that leaves induced to senesce by exposure to dark display characteristic features of dedifferentiating cells, including chromatin decondensation, disruption of the nucleolus, and condensation of rRNA genes. Considering that premature senescence can be induced by various stress conditions both in plant and animal cells, our results suggest that the response of plant and also animal cells to certain stresses converges on cellular dedifferentiation whereby cells first acquire stem cell-like state prior to acquisition of a new cell fate (e.g., reentry into the cell cycle or death).
去分化是指体细胞获得干细胞样特性的能力。这个过程可以在正常发育过程中发生，也可以作为对各种刺激的反应，如病原体感染和创伤。去分化还描述了分化的叶细胞向原生质体（没有细胞壁的植物细胞）的转变，这一转变伴随着广泛的染色质解凝聚。对去分化原生质体细胞的转录组分析显示与衰老细胞惊人地相似；两者都显示出特定转录因子（TF）家族基因表达的大量增加，包括 ANAC、WRKY、bZIP 和 C2H2。进一步的分析表明，通过暴露在黑暗中来诱导衰老的叶片显示出去分化细胞的特征，包括染色质解凝聚、核仁破裂和 rRNA 基因的浓缩。考虑到植物和动物细胞都可以被各种应激条件诱导过早衰老，我们的结果表明，植物和动物细胞对某些应激的反应都集中在细胞去分化上，即细胞在获得新的细胞命运（例如，重新进入细胞周期或死亡）之前首先获得干细胞样状态。
