Zhou Jing, Yang Ling-Yu, Jia Chen-Lin, Shi Wen-Guang, Deng Shu-Rong, Luo Zhi-Bin
State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Silviculture of the National Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing, China.
Front Plant Sci. 2022 Jul 8;13:941380. doi: 10.3389/fpls.2022.941380. eCollection 2022.
Circular RNAs (circRNAs) are a class of noncoding RNA molecules with ring structures formed by covalent bonds and are commonly present in organisms, playing an important regulatory role in plant growth and development. However, the mechanism of circRNAs in poplar root responses to different forms of nitrogen (N) is still unclear. In this study, high-throughput sequencing was used to identify and predict the function of circRNAs in the roots of poplar exposed to three N forms [1 mM NO (T1), 0.5 mM NHNO (T2, control) and 1 mM NH (T3)]. A total of 2,193 circRNAs were identified, and 37, 24 and 45 differentially expressed circRNAs (DECs) were screened in the T1-T2, T3-T2 and T1-T3 comparisons, respectively. In addition, 30 DECs could act as miRNA sponges, and several of them could bind miRNA family members that play key roles in response to different N forms, indicating their important functions in response to N and plant growth and development. Furthermore, we generated a competing endogenous RNA (ceRNA) regulatory network in poplar roots treated with three N forms. DECs could participate in responses to N in poplar roots through the ceRNA regulatory network, which mainly included N metabolism, amino acid metabolism and synthesis, response to NO or NH and remobilization of N. Together, these results provide new insights into the potential role of circRNAs in poplar root responses to different N forms.
环状RNA（circRNAs）是一类具有环状结构的非编码RNA分子，通过共价键形成，普遍存在于生物体中，在植物生长发育中发挥重要的调控作用。然而，circRNAs在杨树根系对不同形态氮（N）响应中的作用机制仍不清楚。在本研究中，利用高通量测序技术鉴定并预测了暴露于三种氮形态[1 mM NO₃⁻（T1）、0.5 mM NH₄NO₃（T2，对照）和1 mM NH₄⁺（T3）]下杨树根系中circRNAs的功能。共鉴定出2193个circRNAs，在T1-T2、T3-T2和T1-T3比较中分别筛选出37、24和45个差异表达的circRNAs（DECs）。此外，30个DECs可作为miRNA海绵，其中一些可结合在响应不同氮形态中起关键作用的miRNA家族成员，表明它们在响应氮及植物生长发育中具有重要功能。此外，我们构建了三种氮形态处理的杨树根系中的竞争性内源RNA（ceRNA）调控网络。DECs可通过ceRNA调控网络参与杨树根系对氮的响应，该网络主要包括氮代谢、氨基酸代谢与合成、对NO₃⁻或NH₄⁺的响应以及氮的再分配。这些结果共同为circRNAs在杨树根系对不同氮形态响应中的潜在作用提供了新的见解。
