Abstract
BackgroundPhalaenopsis orchids are one of the most common potted orchids sold worldwide. Most Phalaenopsis cultivars have long inflorescences that cause shipping problems and increase handling costs. Miniaturization of Phalaenopsis orchids not only reduces overall production costs but also can expand the appeal of the orchids to a different group of consumers who prefer to keep flowers on desks or tabletops. Although some miniature Phalaenopsis plants can be obtained via hybridization or mutation, they are unpredictable and limited in variety. We therefore used the transgenic approach of overexpressing gibberellin 2-oxidase 6 (OsGA2ox6), a rice GA deactivation gene, to investigate its functional effect in miniaturizing Phalaenopsis and to create a stable miniaturization platform to facilitate a supply for the potential demands of the miniature flower market.ResultsA commercial moth orchid, Phalaenopsis Sogo Yukidian ‘SPM313’, was transformed with the plasmid vector Ubi:OsGA2ox6 and successfully overexpressed the OsGA2ox6 gene in planta. The transgenic lines displayed darker-green, shorter, and wider leaves, thicker roots and much shorter flower spikes (10 cm vs 33 cm) than the nontransgenic line with a normal flower size and blooming ability and are therefore an ideal miniaturized form of Phalaenopsis orchids.ConclusionsWe demonstrated that the ectopic expression of OsGA2ox6 can miniaturize Phalaenopsis Sogo Yukidian ‘SPM313’ while preserving its blooming ability, providing an alternative, useful method for miniaturizing Phalaenopsis species. This miniaturization by a transgenic approach can be further expanded by using GA2ox genes from different plant species or different gene variants, thereby expanding the technical platform for miniaturizing Phalaenopsis species to meet the potential demands of the miniature Phalaenopsis flower market.
Highlights
Phalaenopsis orchids are one of the most common potted orchids sold worldwide
Generation of OsGA2ox6‐overexpressing (GA2ox6‐OX) transgenic Phalaenopsis orchids To investigate how a rice C 20-type GA2oxs can affect the growth of Phalaenopsis orchid plants and be used as a method to miniaturize Phalaenopsis species for the floriculture market, a plasmid (Ubi:OsGA2ox6) (Fig. 1a) with the OsGA2ox6 gene driven by a maize ubiquitin promoter was introduced into Protocorm-like bodies (PLBs) of Phalaenopsis Sogo Yukidian ‘SPM313’ (Fig. 1b) by agrobacterium-mediated transformation
To explore whether this phenomenon can be maintained in subsequent subculture processes, the PLBs from the NT and GA2ox6-OX transgenic lines (Fig. 1j, k) were cut horizontally (Additional file 1: Fig S2) to expose their surrounding epidermal cells to generate new PLBs (Fig. 1l, m)
Summary
Phalaenopsis orchids are one of the most common potted orchids sold worldwide. Most Phalaeno‐ psis cultivars have long inflorescences that cause shipping problems and increase handling costs. Miniaturization of Phalaenopsis orchids reduces overall production costs and can expand the appeal of the orchids to a dif‐ ferent group of consumers who prefer to keep flowers on desks or tabletops. For commercial production in floriculture markets, plant growth retardants (PGRs), a group of synthetic bioregulators, have been widely used to shape plant morphology, e.g., to create miniature Phalaenopsis orchids (Lopez et al 2007). Miniature Phalaenopsis orchids benefit commercial producers by reducing handling costs and may be desired by a different group of consumers. Even though miniature orchids such as Phalaenopsis equestris have been used as breeding parents to reduce plant stature (Frowine 2007; Hus and Chen 2015), introducing miniature orchids into a breeding program often produces progeny with small flowers that are not desirable in the market
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
