Circadian-regulated lncCDF1 and its natural antisense transcript CDF1 constitute a novel regulatory module to control drought stress responses in Arabidopsis thaliana
Loading...
Files
Full Text E-thesis
Date
2026-07-21
Authors
Coomey, Chris
Journal Title
Journal ISSN
Volume Title
Publisher
University College Cork
Published Version
Abstract
Drought is a critical abiotic stress that has significant impacts on plant growth and productivity. In recent years long non-coding RNAs (lncRNAs) have emerged as key regulators of plant processes, with direct involvement in developmental transitions (e.g., germination, flowering time, senescence), or in the responses to abiotic stress conditions (e.g., cold, drought). Here I investigated a novel circadian lncRNA, lncCDF1, which is a natural antisense transcript (NAT) to CYCLING DOF FACTOR 1 (CDF1). Previous studies showed that lnccdf1 mutants performed better under drought stress conditions, suggesting a role for this lncRNA in mediating these responses. To further characterise this phenotype, we examined flowering time of wildtype (Col-0), lncCDF1 overexpressor lines, the lnccdf1 knockdown mutant, the cdf-quadruple mutant and the HA-CDF1 overexpressor line grown under control and drought conditions. Our findings showed that lncdf1 mutant had a late-flowering phenotype, whereas lncCDF1 overexpressors displayed early flowering. In parallel, we performed genome-wide transcriptional profiling of wildtype (Col-0), lncCDF1 overexpressors and mutant, and HA-CDF1 overexpressing line to determine the expression of CDF1/lncCDF1 and five drought-responsive genes. Three of these genes; SUC7, OSM34 and MFT displayed upregulated transcription under drought conditions in the lnccdf1 mutant. The other two genes QQS and EXT1 exhibited altered responses to drought stress in lncCDF1 transgenic lines. Finally, we performed starch and soluble sugar analysis to assess diurnal sugar metabolism in lncCDF1 transgenic lines under drought conditions. Our results indicate that lncCDF1 alters starch and soluble sugar metabolism especially at ZT6 and ZT16. Notably, we observed an increase of soluble sugars in the lncCDF1 overexpressors under drought conditions at ZT6. Moreover, under control conditions the lnccdf1 mutant accumulated less soluble sugars compared with wildtype, but drought treated plants displayed a consistent increase across all timepoints. Considering that lncCDF1 modulates CDF1 transcription and waveform we propose that this novel NAT pair could potentially coordinate developmental timing and metabolic stress responses, highlighting new insights into lncRNA-mediated drought tolerance.
Description
Keywords
Drought , Long non-coding RNA , Transcriptomic profiling
Citation
Coomey, C. 2026. Circadian-regulated lncCDF1 and its natural antisense transcript CDF1 constitute a novel regulatory module to control drought stress responses in Arabidopsis thaliana. MRes Thesis, University College Cork.