Suppression of microRNA168 enhances salt tolerance in rice (Oryza sativa L.)

• DOI: 10.1186/s12870-022-03959-1
• Publication Date: 2022-12-03T02:02:23Z
• Authors: Jiong Wan; Shujun Meng; Qiyue Wang; Jiawen Zhao; Xiaoqian Qiu; Liangfa Wang; Juan Li; Yuan Lin; Liqin Mu; Kuntai Dang; Qiankun Xie; Jihua Tang; Dong Ding; Zhanhui Zhang
• Keywords: 0301 basic medicine; 2. Zero hunger; 0303 health sciences; miR168; Research; Salt stress; Botany; Oryza; Salt Tolerance; 15. Life on land; Salt Stress; MicroRNAs; 03 medical and health sciences; Seedlings; QK1-989; Rice; STTM; Gene regulation cascades

Abstract Background Rice is a salt-sensitive crop. Complex gene regulatory cascades are likely involved in salinity stress in rice roots. microRNA168 (miR168) is a conserved miRNA among different plant species. It in-directly regulates the expression of all miRNAs by targeting gene ARGONAUTE1(AGO1). Short Tandem Target Mimic (STTM) technology is an ideal approach to study miRNA functions by in-activating mature miRNA in plants.

Results In this study, rice miR168 was inactivated by STTM. The T3 generation seedlings of STTM168 exhibited significantly enhanced salt resistance. Direct target genes of rice miR168 were obtained by in silico prediction and further confirmed by degradome-sequencing. PINHEAD (OsAGO1), which was previously suggested to be a plant abiotic stress response regulator. RNA-Seq was performed in root samples of 150mM salt-treated STTM168 and control seedlings. Among these screened 481 differentially expressed genes within STTM168 and the control, 44 abiotic stress response related genes showed significant difference, including four known salt-responsive genes.

Conclusion Based on sequencing and qRT-PCR, a “miR168-AGO1-downstream” gene regulation model was proposed to be responsible for rice salt stress response. The present study proved miR168-AGO1 cascade to play important role in rice salinity stress responding, as well as to be applied in agronomic improvement in further.