PLANT CELL: 美国科学家解析植物花序分支形成的分子机制
Figure 2 Images and diagrams of spikelets of wheat (Triticum turgidum cv. “Kronos”), rice (O. sativa), barley (H. vulgare, only central spikelet diagrammed), and maize (Z. mays, tassel spikelet). Paleas not visible in photos of wheat and barley. Shaded ovals (yellow) indicate floral organs as shown in inset, upper right. Glumes indicated by thickened arcs (green); lemmas and paleas, black arcs; suppressed meristems, x. Scale bars, 0.5 mm. Distance between structures in diagrams is exaggerated for clarity. Image of barley spikelet reproduced from Komatsuda et al. (2007); copyright 2007 National Academy of Sciences. Scale bar lacking in original. an, anther; gl, glume; lo, lodicle; pa, palea; st, stigma.
Figure 3 Inflorescence diagrams of rice (O. sativa), barley (H. vulgare), wheat (T. aestivum), and maize (Z. mays). Spikelets indicated by ovals (green); suppressed bracts, arcs below the ovals (orange). IMs lacking a terminal flower indicated by asterisks (magenta).
Figure 4 BA1/LAX1 (boundary domain), RA2 (axillary meristem), and TSH4 (suppressed bract) regulatory networks. Subnetworks in boxes are widely conserved among the grasses. aOrtholog in rice not involved in regulating LAX1LAX2. bNo data on orthologs in other grasses. cRA2/HvRA2 are expressed adjacent to the meristem but not overlapping with BA1 + BA2. dGene absent in rice and barley genomes. Dashed lines indicate regulatory connection inferred from gene expression and mutant phenotypes, following Yao et al. (2019). For genes with different names in different species, the first name is the maize gene name (black), second is rice (magenta), and third is barley (cyan).
Figure 5 A, miR156-SPL-miR172-AP2-like regulatory networks. B, Developmental window showing the transition from axillary BMs to spikelet formation, with major genes marking each stage and opposing gradients of microRNAs. Species- and clade-specific inflorescence morphology is influenced by the developmental timing of the transition; shorter time causes a faster transition to glume production which in turn leads to fewer branches and vice versa. In rice, transition time appears to vary continuously across the inflorescence; in maize, transition time is bimodal (long and short, but nothing in between); in barley, transition time is unimodal, only short. Portions of the figure are redrawn from Wang et al., (2015, Supplemental Figure S16).
原文：Genetic control of branching patterns in grass inflorescences
