Molecular mechanisms regulating ornamental traits and scent production in snapdragon (Antirrhinum majus L.)

Abstract

Snapdragon (Antirrhinum majus L.) is a widely cultivated and economically important cut flower and bedding plant worldwide due to its high ornamental value. At the same time, owing to its herbaceous features, ease of growth and cultivation, short life cycle, diploid inheritance, diverse morphological variation, and self-incompatibility, it has also been used as a model plant for studies on molecular biology, biochemistry, and plant developmental genetics. Over the past few decades, hundreds of plant genetics and physiology studies have been published on snapdragon. This review aims to summarize the advances in the characterization of snapdragon ornamental characters associated with floral organ size, shape, scent, color, and plant appearance. A broad spectrum of genes and their action mechanisms were explored and discussed, including comprehensive investigations at the genome-wide level and unraveling the functions of structural genes and master regulators and their interactions. In addition, the biosynthetic pathway involved in floral volatile scent production was summarized. Finally, the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTORS (TCP) family in snapdragon was investigated using the latest whole-genome data. This review will lay the foundation for future molecular genetics and genomics research and applications on snapdragon. It further contributes to improve our knowledge of the mechanisms regulating morphogenesis and ornamental qualities in snapdragon.