State Key Laboratory of Grassland Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China.
Genes (Basel). 2019 Jul 30;10(8):573. doi: 10.3390/genes10080573.
The identification of biological mechanisms underlying the development of complex quantitative traits, including those that contribute to plant architecture, yield and quality potential, and seed dispersal, is a major focus in the evolutionary biology and plant breeding. The awn, a bristle-like extension from the lemma in the floret, is one of the distinct morphological and physiological traits in grass species. Awns are taught as an evolutionary trait assisting seed dispersal and germination and increasing photosynthesis. Awn development seems to be complex process, involving dramatic phenotypic and molecular changes. Although recent advances investigated the underlying morphological and molecular genetic factors of awn development, there is little agreement about how these factors interact during awn formation and how this interaction affects variation of awn morphology. Consequently, the developmental sequence of the awn is not yet well understood. Here, we review awn morphological and histological features, awn development pathways, and molecular processes of awn development. We argue that morphological and molecular genetic mechanisms of awn development previously studied in major cereal crops, such as barley, wheat, and rice, offered intriguing insights helping to characterize this process in a comparative approach. Applying such an approach will aid to deeply understand factors involved in awn development in grass species.
鉴定复杂数量性状（包括那些对植物结构、产量和品质潜力以及种子散布有贡献的性状）背后的生物学机制是进化生物学和植物育种的主要重点。芒，小花内的外稃上的刚毛状延伸物，是禾本科植物的独特形态和生理特征之一。芒被认为是一种有助于种子散布和发芽以及增加光合作用的进化特征。芒的发育似乎是一个复杂的过程，涉及显著的表型和分子变化。尽管最近的研究进展调查了芒发育的潜在形态和分子遗传因素，但对于这些因素在芒形成过程中如何相互作用以及这种相互作用如何影响芒形态的变异，仍存在分歧。因此，芒的发育顺序尚不完全清楚。在这里，我们回顾了芒的形态和组织学特征、芒的发育途径以及芒发育的分子过程。我们认为，在大麦、小麦和水稻等主要谷类作物中研究的芒发育的形态和分子遗传机制提供了有趣的见解，有助于以比较的方式描述这个过程。应用这种方法将有助于深入了解禾本科植物中芒发育所涉及的因素。
