背景回顾：Flowering plants with indeterminate inflorescences often produce more floral structures than they require. 

主要发现：We found that floral primordia initiations in barley (Hordeum vulgare L.) are molecularly decoupled from their maturation into grains. While initiation is dominated by flowering-time genes, floral growth is specified by light signaling, chloroplast, and vascular developmental programs orchestrated by barley CCT MOTIF FAMILY 4 (HvCMF4), which is expressed in the inflorescence vasculature. 

结果1：Consequently, mutations in HvCMF4 increase primordia death and pollination failure, mainly through reducing rachis greening and limiting plastidial energy supply to developing heterotrophic floral tissues. 

结果2：We propose that HvCMF4 is a sensory factor for light that acts in connection with the vascular-localized circadian clock to coordinate floral initiation and survival. Notably, stacking beneficial alleles for both primordia number and survival provides positive implications on grain production. 

结论：Our findings provide insights into the molecular underpinnings of grain number determination in cereal crops.

具无限花序的有花植物通常能够产生多于其所需要的花结构。作者发现大麦中花原基起始与其成熟形成籽粒在分子上是解偶联的。花原基起始主要受到开花相关基因的调控，而花生长受到光信号转导、叶绿体和维管发育的影响，其中维管发育主要受到在花序维管表达的基因HvCMF4的调控。HvCMF4基因的功能缺失突变会导致原基死亡和授粉失败，而这主要是通过减少花序轴绿化以及限制向异养花组织的质体能量供应。作者提出，HvCMF4是一个光感受器，与定位于维管的生物钟共同作用，协调花起始和存活。通过增加同时能够促进原基数量和存活的有益基因，对于作物的籽粒产量将产生积极的影响。本文的研究为谷类作物中作用于籽粒数量决定的分子基础提供了新的见解。