Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA;
Genome Res. 2014 Mar;24(3):431-43. doi: 10.1101/gr.166397.113. Epub 2013 Dec 4.
Genetic control of branching is a primary determinant of yield, regulating seed number and harvesting ability, yet little is known about the molecular networks that shape grain-bearing inflorescences of cereal crops. Here, we used the maize (Zea mays) inflorescence to investigate gene networks that modulate determinacy, specifically the decision to allow branch growth. We characterized developmental transitions by associating spatiotemporal expression profiles with morphological changes resulting from genetic perturbations that disrupt steps in a pathway controlling branching. Developmental dynamics of genes targeted in vivo by the transcription factor RAMOSA1, a key regulator of determinacy, revealed potential mechanisms for repressing branches in distinct stem cell populations, including interactions with KNOTTED1, a master regulator of stem cell maintenance. Our results uncover discrete developmental modules that function in determining grass-specific morphology and provide a basis for targeted crop improvement and translation to other cereal crops with comparable inflorescence architectures.
遗传控制分枝是产量的主要决定因素，调节种子数量和收获能力，但关于塑造谷类作物结实花序的分子网络知之甚少。在这里，我们使用玉米（Zea mays）花序来研究调节确定性的基因网络，特别是允许分枝生长的决定。我们通过将时空表达谱与遗传干扰导致的形态变化相关联来描述发育转变，这些干扰破坏了控制分枝的途径中的步骤。转录因子 RAMOSA1 靶向基因的发育动态，揭示了在不同干细胞群体中抑制分支的潜在机制，包括与 KNOTTED1 的相互作用，KNOTTED1 是干细胞维持的主要调节剂。我们的研究结果揭示了在确定草类特有形态中起作用的离散发育模块，并为有针对性的作物改良提供了基础，并可转化为具有类似花序结构的其他谷类作物。
