Overexpression of lncRNA22524 from Dongxiang Wild Rice Reduces Drought and Salt Stress Tolerance in Cultivated Rice

Drought and salt stresses are major challenges to rice production, and a deep understanding of the mechanisms for tolerance could help deal with the challenges. Long non-coding RNAs (lncRNAs) play crucial roles in gene regulation. Previously, lncRNA22524 has been identified as a drought stress-responsive lncRNA from Dongxiang wild rice (DXWR). Nevertheless, its reactions to abiotic stresses in genetics and physiology remained unclear. In this study, we employed a rapid amplification of cDNA ends (RACE) to obtain the full-length cDNA of lncRNA22524 from DXWR, analyzed its cellular localization, built an overexpression vector to generate transgenic lines of cultivated rice and evaluated its impact in genetics and physiology. After treated with drought and salt stress, the overexpressed lines exhibited much more injuries and lower rates of survival, more reactive oxygen species (ROS) and malondialdehyde (MDA), lower antioxidant enzymes and lower proline (Pro) and soluble sugar (SS) than their wild-type (WT). Furthermore, transcriptome analysis of overexpressed lines with weaker tolerance than WT revealed 1,233 differentially expressed genes (DEGs), where most DEGs were involved in phenylpropanoid biosynthesis, photosynthesis and glutathione metabolism. These findings demonstrated that lncRNA22524 negatively regulated rice responses to drought and salt stress, which clear way of working from transcription to metabolic products should be worth of further study.