Guan Bin, Lin Ze, Liu Dongcheng, Li Chengyang, Zhou Zhuqing, Mei Fangzhu, Li Jiwei, Deng Xiangyi
Laboratory of Cell Biology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.
College of Plant Sciences and Technology, Huazhong Agricultural University, Wuhan, China.
Front Plant Sci. 2019 Apr 11;10:468. doi: 10.3389/fpls.2019.00468. eCollection 2019.
Autophagy, a highly conserved process in eukaryotes that involves vacuolar degradation of intracellular components and decomposition of damaged or toxic constituents, is induced by endogenous reactive oxygen species (ROS) accumulation, endoplasmic reticulum stress, and other factors. In plants, the role of autophagy in the induction of programmed cell death (PCD) is still unclear. Here, we show that ROS contribute to the regulation of PCD during waterlogging (which results in oxygen depletion) via autophagy. In wild-type roots, waterlogging induces the transcription of hypoxia-responsive genes and respiratory burst oxidase homolog (RBOH)-mediated ROS production. It also altered the transcription level of alternative oxidase1a and the activity level of antioxidant enzymes. Moreover, waterlogging increased the transcription levels of autophagy-related () genes and the number of autophagosomes. Autophagy first occurred in the root stele, and then autophagosomes appeared at other locations in the root. In mutants, upregulation of autophagosomes was less pronounced than in the wild type upon waterlogging. However, the accumulation of ROS and the level of cell death in the roots of mutants were higher than those in the wild type after waterlogging. In conclusion, our results suggest that autophagy induced in roots during waterlogging has an attenuating effect on PCD in the roots.
自噬是真核生物中一个高度保守的过程，涉及细胞内成分的液泡降解以及受损或有毒成分的分解，它由内源性活性氧（ROS）积累、内质网应激和其他因素诱导。在植物中，自噬在程序性细胞死亡（PCD）诱导中的作用仍不清楚。在此，我们表明ROS通过自噬在涝渍（导致氧气耗尽）期间对PCD的调节起作用。在野生型根中，涝渍诱导缺氧响应基因的转录以及呼吸爆发氧化酶同源物（RBOH）介导的ROS产生。它还改变了交替氧化酶1a的转录水平和抗氧化酶的活性水平。此外，涝渍增加了自噬相关（）基因的转录水平和自噬体的数量。自噬首先发生在根中柱，然后自噬体出现在根的其他部位。在突变体中，涝渍后自噬体的上调不如野生型明显。然而，涝渍后突变体根中ROS的积累和细胞死亡水平高于野生型。总之，我们的结果表明，涝渍期间根中诱导的自噬对根中的PCD具有减弱作用。
