Institute of Crop Science, National Agriculture and Food Research Organization (NARO), 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602, Japan.
Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo, Chiba, 271-8510, Japan.
Plant J. 2023 Nov;116(3):887-902. doi: 10.1111/tpj.16416. Epub 2023 Aug 7.
Floral morphology varies considerably between dicots and monocots. The ABCDE model explaining how floral organ development is controlled was formulated using core eudicots and applied to grass crops. Barley (Hordeum. vulgare) has unique floral morphogenesis. Wild barley (H. vulgare ssp. spontaneum), which is the immediate ancestor of cultivated barley (H. vulgare ssp. vulgare), contains a rich reservoir of genetic diversity. However, the wild barley genes involved in floral organ development are still relatively uncharacterized. In this study, we generated an organ-specific transcriptome atlas for wild barley floral organs. Genome-wide transcription profiles indicated that 22 838 protein-coding genes were expressed in at least one organ. These genes were grouped into seven clusters according to the similarities in their expression patterns. Moreover, 5619 genes exhibited organ-enriched expression, 677 of which were members of 47 transcription factor families. Gene ontology analyses suggested that the functions of the genes with organ-enriched expression influence the biological processes in floral organs. The co-expression regulatory network showed that the expression of 690 genes targeted by MADS-box proteins was highly positively correlated with the expression of ABCDE model genes during floral morphogenesis. Furthermore, the expression of 138 genes was specific to the wild barley OUH602 genome and not the Morex genome; most of these genes were highly expressed in the glume, awn, lemma, and palea. This study revealed the global gene expression patterns underlying floral morphogenesis in wild barley. On the basis of the study findings, a molecular mechanism controlling floral morphology in barley was proposed.
双子叶植物和单子叶植物的花形态差异很大。解释花器官发育如何被控制的 ABCDE 模型是使用核心真双子叶植物建立的，并应用于禾本科作物。大麦（Hordeum vulgare）具有独特的花形态发生。野生大麦（Hordeum vulgare ssp. spontaneum）是栽培大麦（Hordeum vulgare ssp. vulgare）的直接祖先，含有丰富的遗传多样性。然而，参与花器官发育的野生大麦基因仍相对未被表征。在这项研究中，我们生成了野生大麦花器官的器官特异性转录组图谱。全基因组转录谱表明，至少有 22838 个蛋白质编码基因在至少一个器官中表达。这些基因根据表达模式的相似性被分为七个簇。此外，5619 个基因表现出器官特异性表达，其中 677 个是 47 个转录因子家族的成员。基因本体分析表明，器官特异性表达基因的功能影响花器官中的生物学过程。共表达调控网络表明，在花形态发生过程中，MADS 框蛋白靶向的 690 个基因的表达与 ABCDE 模型基因的表达高度正相关。此外，有 138 个基因的表达是野生大麦 OUH602 基因组特有的，而不是 Morex 基因组特有的；这些基因大多数在颖片、芒、外稃和内稃中高度表达。本研究揭示了野生大麦花形态发生的全局基因表达模式。基于研究结果，提出了控制大麦花形态的分子机制。
