The rice panicle (A) has a defined architecture derived from the meristematic structure established early in inflorescence development (B, C), characterized by diagnostic changes in the gene expression pattern (D). (A) Panicle architecture. Representative primary branch (PB), secondary branch (SB), lateral and terminal spikelet (LS and TS) are labeled. (B) Developmental stages of the reproductive meristem, which produces primary branch meristems (PBM), secondary branch meristems (SBM), lateral and terminal spikelet meristems (LSM, TSM), which then give rise to floral meristems (LFM, TFM). (C) Light microscope images (scale bar = 100μm). (D) Diagnostic changes in gene expression occurring during early panicle development based on qRT-PCR using three biological replicates with reproductive stages as defined in (C). Statistical analysis performed by ANOVA with Holm post-test to compare stage 0 to stages 1–5 (* p < 0.05, ** p < 0.01).