Abstract：
Inflorescence architecture and crop productivity are often tightly coupled in our major cereal crops. However, the underlying genetic mechanisms controlling cereal inflorescence development remain poorly understood. Here, we identified recessive alleles of barley (Hordeum vulgare L.) HvALOG1 (Arabidopsis thaliana LSH1 and Oryza G1) that produce non-canonical extra spikelets and fused glumes abaxially to the central spikelet from the upper-mid portion until the tip of the inflorescence. Notably, we found that HvALOG1 exhibits a boundary-specific expression pattern that specifically excludes reproductive meristems, implying the involvement of previously proposed localized signaling centers for branch regulation. Importantly, during early spikelet formation, non-cell-autonomous signals associated with HvALOG1 expression may specify spikelet meristem determinacy, while boundary formation of floret organs appears to be coordinated in a cell-autonomous manner. Moreover, barley ALOG family members synergistically modulate inflorescence morphology, with HvALOG1 predominantly governing meristem maintenance and floral organ development. We further propose that spatiotemporal redundancies of expressed HvALOG members specifically in the basal inflorescence may be accountable for proper patterning of spikelet formation in mutant plants. Our research offers new perspectives on regulatory signaling roles of ALOG transcription factors during the development of reproductive meristems in cereal inflorescences.
摘要：
在我们的主要谷类作物中，花序结构和作物生产力通常紧密耦合。然而,控制谷物花序发育的潜在遗传机制仍然知之甚少。这里,我们确定了大麦（HordeumvulgareL.）HvALOG1（拟南芥LSH1和OryzaG1）的隐性等位基因，这些等位基因会产生非规范的额外小穗，并从上中部到中央小穗的背面融合，直到花序的尖端。值得注意的是,我们发现HvALOG1表现出特异性排除生殖分生组织的边界特异性表达模式，暗示涉及先前提出的用于分支监管的本地化信令中心。重要的是,在小穗形成早期，与HvALOG1表达相关的非细胞自主信号可能指定小穗分生组织的确定性，而小花器官的边界形成似乎以细胞自主的方式协调。此外，大麦ALOG家族成员协同调节花序形态，HvALOG1主要控制分生组织维持和花器官发育。我们进一步提出，在基底花序中特异性表达的HvALOG成员的时空冗余可能是突变植物中小穗形成的正确模式的原因。我们的研究为ALOG转录因子在谷物花序生殖分生组织发育过程中的调控信号作用提供了新的视角。
