Transcriptomic profiling of awn development in oat (Avena sativa L.) spikelets at six developmental stages

Spikelets were manually dissected and staged based on morphological characterization and SEM image analysis. Six developmental stages were sampled: awn primordium (AP), awn initial elongation (AIE), awn rapid elongation (ARE), early heading (EHD), middle heading (MHD), and late heading (LHD).

These stages represent relatively stable developmental states rather than transient expression peaks, minimizing temporal mismatch between transcript and metabolite accumulation. To ensure consistent developmental staging, spikelets were sampled from the middle of panicles. Each stage was represented by three biological replicates per genotype (≥200 spikelets per sample).