State Key Laboratory of Plant Genomics, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, 050021, China.
State Key Laboratory of Plant Genomics, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang, Hebei, 050021, China.
Biochem Biophys Res Commun. 2020 Oct 22;531(4):503-507. doi: 10.1016/j.bbrc.2020.07.061. Epub 2020 Aug 15.
Plant innate immunity varies with age and plant developmental stages. Recently, we reported that Arabidopsis thaliana microRNA miR172b regulates FLS2 transcription through two transcription factors: TARGET OF EAT1 (TOE1) and TOE2. Although the flg22-triggered immune responses were investigated in 2-d-old or even younger toe1/toe2 mutant and miR172b over expression (OE) transgenic plants, the FLS2-mediated immune responses in older plants remain uncharacterized yet. In this work, we analyzed the flg22-triggered immune response in 6-d-old toe1/toe2 and miR172b OE plants. We found that unlike 2-d-old plants, 6-d-old Col-0, toe1/toe2 and miR172b OE plants exhibit comparable flg22-triggered immune responses. Strikingly, miR172b precursor in 6-d-old Col-0 plants upon flg22 treatment reached to a very high level, consequently, the TOE1/2 protein level under this condition was very low or almost undetectable, which explains why 6-d-old WT seedlings are very similar to toe1/toe2 seedlings or miR172b OE plants with respect to the flg22-triggered immune responses. Taken together, our study reveals that miR172b-TOE1/2 module regulates plant innate immunity in an age-dependent manner.
植物先天免疫随年龄和植物发育阶段而变化。最近，我们报道拟南芥 microRNA miR172b 通过两个转录因子：EAT1 靶蛋白（TOE1）和 TOE2 来调节 FLS2 转录。虽然已经研究了 flg22 触发的免疫反应在 2 天龄或更年轻的 toe1/toe2 突变体和 miR172b 过表达（OE）转基因植物中，但尚未对老年植物中的 FLS2 介导的免疫反应进行表征。在这项工作中，我们分析了 6 天龄 toe1/toe2 和 miR172b OE 植物中的 flg22 触发的免疫反应。我们发现，与 2 天龄植物不同，6 天龄 Col-0、toe1/toe2 和 miR172b OE 植物表现出可比的 flg22 触发的免疫反应。引人注目的是，在 flg22 处理下，6 天龄 Col-0 植物中的 miR172b 前体达到非常高的水平，因此，在这种情况下，TOE1/2 蛋白水平非常低或几乎无法检测到，这解释了为什么 6 天龄 WT 幼苗在 flg22 触发的免疫反应方面与 toe1/toe2 幼苗或 miR172b OE 植物非常相似。总之，我们的研究表明，miR172b-TOE1/2 模块以年龄依赖的方式调节植物先天免疫。
