Transcriptome analyses provide insights into development of the Zingiber zerumbet flower, revealing potential genes related to floral organ formation and patterning
The flower of Zingiber zerumbet is characterized by a distinctive labellum, a highly modified floral organ believed to be formed by the fusion of several infertile members of the androecial whorl (staminodes). Across the Zingiberaceae, the number of staminodes involved in labellum formation varies from two to four, and these are reflected in the number of lobes that comprise the mature labellum. Research on the flower development in Zingiberaceae has been limited to species with either no labellum lobes or species displaying a bilobed labellum. Zingiber zerumbet is a representative of the genus with a three-lobed labellum, and its flower development remains poorly understood at both morphological and molecular levels. This study aims to give a comprehensive description of its flower development and to identify potential genes related to flower development using morphological and genetic characterization. Our results show that floral organ initiation is sequential with the sepal whorl initiating first, followed by petal and inner androecium together, followed by outer androecium, and finally the initiation of the inferior gynoecium. The three-lobed labellum comprises four androecial members: Two abaxial inner androecial members fuse to form the single central lobe, and two adaxial outer androecial members individually form the two lateral lobes of the labellum. Two developmental stages (floral primordium and organ-differentiated flowers) were selected for transcriptome sequencing. Two-thousand and seventy-five transcription factors were identified. Seven boundary genes and seven organ-specific genes were also discovered. Our study provides fundamental information for further studies on the molecular mechanisms of flower development and evolution across the Zingiberaceae.
KeywordsFlower development Labellum Transcriptome Floral organ fusion Zingiber zerumbet
This work is supported by the National Natural Science Foundation of China (Grant Nos. 31670336, 31200246, 31271318) and Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences (Grant No. Y821171001). We thank Haoran Ding for his assistance with part of the experiments.
TZ performed the experiments, analyzed the data and wrote the manuscript. HFL designed the research and performed the experiments. CDS and ZCD performed parts of the data analysis and CDS helped write parts of the discussion. YSY and JPL provided assistance with samples collection and offered some photos of Z. zerumbet. All authors contributed to the manuscript revision.
Compliance with ethical standards
Conflict of interest
All authors declare that they have no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
- Costerus JC (1915) Das Labellum und das Diagram der Zingiberaceen. Ann Jardin Botanique Buitenzorg II 14:95–108Google Scholar
- Eichler AW (1884) Uber den bluthenbau der Zingiberaceen. Sitzungsber der Königlich Preuss. Akad Wiss 26:585–600Google Scholar
- Huang JZ, Lin CP, Cheng TC et al (2015) A de novo floral transcriptome reveals clues into Phalaenopsis orchid flower development. PLoS ONE 10:1–20Google Scholar
- Kirchoff BK (1988a) Floral ontogeny and evolution in the ginger group of the Zingiberales. In: Leins P, Tucker SC, Endress PK (eds) Aspects of floral development. Cramer, Berlin, pp 45–56Google Scholar
- Lestiboudois T (1829) Notice sur le genre Hedychium de la famille des Musacees (Balisiers et Bananiers). Annu Sci Natl Premium Service 17:113–139Google Scholar
- Renner T, Bragg J, Driscoll HE et al (2009) Viral induced gene silencing as a tool for investigating floral developmental genetics in the Zingiberales. Mol Plant 3:1–11Google Scholar
- Schachner J (1924) Beitrage zur Kenntnis der Bluten und Samenentwicklung der Scitamineen. Flora 117:16–40Google Scholar
- Schumann K (1904) Zingiberaceae. Pflanzenreich 20(4):46Google Scholar
- Specht CD, Almeida AMR (2017) A process-based approach to the study of flower morphological variation. In: Nuño de la Rosa L, Müller G (eds) Evolutionary developmental biology. Springer, Cham, pp 1–15Google Scholar
- Tian X, Yu Q, Liu H et al (2016) Temporal-spatial transcriptome analyses provide insights into the development of petaloid androecium in Canna indica. Front Plant Sci 7:1–11Google Scholar
- Yockteng R, Almeida AMR, Piñeyro-Nelson A, Specht CD (2014) Adaptation of floral form: an evo-devo approach to study adaptive evolution in floral morphology. In: Laitinen R (ed) Molecular mechanisms in plant adaptation. Wiley, New York, pp 171–192Google Scholar