Inflorescence and spikelet meristem establishment and maintenance in barley

花序结构控制花，因此种子生产，在很大程度上是由分生组织的身份和确定性决定。草花序分生组织（IM）产生独特的结构，小穗分生组织（SM），然后产生花分生组织（FM），花和种子。如何建立，维护和终止这些不同的分生组织的花序内的遗传控制在温带禾谷类大麦还没有得到很好的理解，我们已经确定并描述了三种不同的转录因子，控制分生组织的确定性和身份转换，从而产生的小穗和花的大麦穗。CEN和INT-M/DUB 1促进了IM的不确定性和小穗分生组织的确定性，而FT 1促进了IM的确定性和小穗分生组织的不确定性。这些结果表明，大麦IM和SM的决定性是遗传协调和负相关。在这里，我们建议使用ft 1，cen，和int-m/dub 1突变体解剖的分子网络花序分生组织的确定性和身份转换。具体而言，我们将（i）使用激光捕获显微切割（LCM）和RNA测序（LCM-RNA-seq）识别FT 1/CEN和INT-M下游转录网络中IM和SM/FM特异性变化，然后对候选基因进行功能分析;（ii）使用激素报告基因系和激素水平变化的测量，破译IM和SM确定性与激素稳态和反应之间的联系。最终的目标是确定分子网络，专门控制不同的大麦分生组织，IM和SM/FM的命运。通过整合来自联盟合作伙伴关于玉米，大麦和Brachypodium中不同干细胞系统调控的信息，我们将能够开发关于谷物干细胞系统分子控制及其在不同分生组织和物种之间变化的共同框架。

Inflorescence architecture controls flower and hence seed production and is largely defined by meristem identity and determinacy decisions. Grass inflorescence meristems (IM) produce a unique structure, spikelet meristems (SM) that then produce floral meristems (FM), flowers, and seeds. How the establishment, maintenance, and termination of these different meristems within the inflorescence are genetically controlled in the temperate cereal barley is not well understood.We have identified and described three different transcription factors that control meristem determinacy and identity transitions and thereby the number of spikelets and flowers produced on the barley spike. CENTRORADIALIS (CEN) and INTERMEDIUM-M/DOUBLE SEED 1 (INT-M/DUB1) promote IM indeterminacy and spikelet meristem (SM) determinacy, while FLOWERING LOCUS T1 (FT1) promotes IM determinacy and SM indeterminacy. These results suggest that IM and SM determinacy are genetically coordinated and negatively correlated in barley. Here, we propose to use ft1, cen, and int-m/dub1 mutants to dissect the molecular network underlying inflorescence meristem determinacy and identity transitions. Specifically, we will (i) identify IM and SM/FM-specific changes in transcriptional networks downstream of FT1/CEN and INT-M using laser capture microdissection (LCM) and RNA-sequencing (LCM-RNA-seq) followed by functional analyses of candidate genes and (ii) decipher the link between IM and SM determinacy and hormone homeostasis and response using hormone reporter lines and measurements of hormone level changes. The ultimate goal is to identify molecular networks that specifically control the fate of the different barley meristems, IM and SM/FM. By integrating information from the consortium partners on the regulation of different stem cell systems in maize, barley and Brachypodium we will be able to develop a common framework on the molecular control of cereal stem cell systems and their variation between different meristems and species.