The State Key Laboratory of Plant Cell & Chromosome Engineering, Center of Agricultural Research Resources, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, China.
Plant Signal Behav. 2010 Dec;5(12):1645-6. doi: 10.4161/psb.5.12.13811. Epub 2010 Dec 1.
Plant root development is highly plastic in order to cope with various environmental stresses; many questions on the mechanisms underlying developmental plasticity of root system remain unanswered. Recently, we showed that autophagic PCD occurs in the region of root apical meristem in response to severe water deficit. We provided evidence that reactive oxygen species (ROS) accumulation may trigger the cell death process of the meristematic cells in the stressed root tips. Analysis of BAX inhibitor-1 (AtBI1) expression and the phenotypic response of atbi1-1 mutant under the severe water stress revealed that AtBI1 and the endoplasmic reticulum (ER) stress response pathway modulate water stress-induced PCD. As a result, the thick and short lateral roots with increased tolerance to the stress are induced. We propose that under severe drought condition, plants activate PCD program in the root apical root meristem, so that apical root dominance is removed. In this way, they can remodel their root system architecture to adapt the stress environment.
植物根系的发育具有高度的可塑性，以应对各种环境胁迫；然而，根系发育可塑性的机制仍有许多问题尚未得到解答。最近，我们发现自噬性程序性细胞死亡（PCD）会在严重缺水时发生于根尖分生组织区域。我们提供的证据表明，活性氧（ROS）的积累可能引发胁迫根尖分生组织细胞的死亡过程。对 BAX 抑制剂-1（AtBI1）表达的分析以及在严重水分胁迫下 atbi1-1 突变体的表型反应表明，AtBI1 和内质网（ER）应激反应途径调节水分胁迫诱导的 PCD。因此，诱导产生了具有更高耐受力的粗壮且短的侧根。我们提出，在严重干旱条件下，植物会在根尖分生组织中激活 PCD 程序，从而去除根尖优势。通过这种方式，它们可以重塑根系结构以适应胁迫环境。
