College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China; State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, People's Republic of China.
State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, People's Republic of China.
Biochem Biophys Res Commun. 2022 Jan 15;588:61-67. doi: 10.1016/j.bbrc.2021.12.030. Epub 2021 Dec 13.
Actinomycin D has been reported to selectively inhibit rRNA synthesis and ribosome biogenesis, induce G2 checkpoint of cell cycle arrest in HeLa cells. In Arabidopsis, actinomycin D was also used as agent to preferentially inhibit the ribosome biosynthesis and ribosomal function. However, the function of actinomycin D on Arabidopsis root development remains to be elucidated. In this study, we exposed Arabidopsis seedlings to actinomycin D with the aim of evaluating the effects of ribosome biogenesis on root development. The results demonstrated that actinomycin D inhibited Arabidopsis root growth by reduced meristematic activity in a dose dependent manner. Exposure to actinomycin D decreased the expression of WOX5 and key stem cell niche-defining transcription factors SHR and PLT1, thus the loss function of QC identity and stem cell niche maintenance. In addition, dead cells were observed after actinomycin D treatment in root stele initials and DNA damage response was constitutively activated. Collectively, we propose that ribosome biogenesis plays key role in primary root growth through maintenance of root stem cell niche and DNA damage response in Arabidopsis.
放线菌素 D 已被报道选择性地抑制 rRNA 合成和核糖体生物发生，诱导 HeLa 细胞的细胞周期 G2 检查点停滞。在拟南芥中，放线菌素 D 也被用作优先抑制核糖体生物发生和核糖体功能的试剂。然而，放线菌素 D 对拟南芥根发育的功能仍有待阐明。在这项研究中，我们用放线菌素 D 处理拟南芥幼苗，目的是评估核糖体生物发生对根发育的影响。结果表明，放线菌素 D 以剂量依赖的方式通过降低分生组织活性抑制拟南芥根的生长。暴露于放线菌素 D 会降低 WOX5 的表达和关键干细胞龛定义转录因子 SHR 和 PLT1，从而丧失 QC 身份和干细胞龛维持的功能。此外，在根中柱原细胞中观察到放线菌素 D 处理后的死亡细胞，并且 DNA 损伤反应持续被激活。总之，我们提出核糖体生物发生通过维持拟南芥根干细胞龛和 DNA 损伤反应在主根生长中起关键作用。
