The study investigates how miR394 influences flowering time in Arabidopsis thaliana by combining transcriptomic profiling of mir394a mir394b double mutants with histological analysis of reporter lines. Bioinformatic analysis identified a novel lncRNA overlapping MIR394B (named MIRAST), and differential promoter activity of MIR394A and MIR394B suggests miR394 fine‑tunes flower development through transcription factor and chromatin remodeler regulation.

The study demonstrates that abscisic acid (ABA) accumulates in darkness to suppress cotyledon opening during seedling deetiolation, and that light exposure lifts this repression, enabling cotyledon aperture. Genome‑wide transcriptional and alternative‑splicing changes accompany this process, and the light‑dependent regulation requires the splicing factors RS40 and RS41, whose activity is repressed in the dark.