Hsieh Kun-Ting, Liu Su-Hui, Wang I-Wen, Chen Liang-Jwu
Institute of Molecular Biology, National Chung Hsing University, Taichung, 40227, Taiwan.
Division of Biotechnology, Taiwan Agriculture Research Institute, Taichung, 41362, Taiwan.
Bot Stud. 2020 Apr 6;61(1):10. doi: 10.1186/s40529-020-00288-0.
Phalaenopsis 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.
A 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.
We 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.
蝴蝶兰是全球最常见的盆栽兰花之一。大多数蝴蝶兰品种的花序较长，这会导致运输问题并增加处理成本。蝴蝶兰的小型化不仅能降低总体生产成本，还能扩大兰花对另一类消费者的吸引力，这类消费者更喜欢将花卉摆放在书桌或桌面上。尽管可以通过杂交或突变获得一些小型蝴蝶兰植株，但它们不可预测且品种有限。因此，我们采用过表达水稻赤霉素失活基因赤霉素2-氧化酶6（OsGA2ox6）的转基因方法，来研究其在蝴蝶兰小型化中的功能效应，并创建一个稳定的小型化平台，以满足微型花卉市场的潜在需求。
用质粒载体Ubi:OsGA2ox6转化商业蝴蝶兰品种“索哥绿翡翠‘SPM313’”，并在植株中成功过表达OsGA2ox6基因。与具有正常花朵大小和开花能力的非转基因株系相比，转基因株系的叶片颜色更深、更短更宽，根系更粗，花穗短得多（10厘米对33厘米），因此是蝴蝶兰理想的小型化形态。
我们证明，OsGA2ox6的异位表达能使“索哥绿翡翠‘SPM313’”小型化，同时保留其开花能力，为蝴蝶兰品种的小型化提供了一种有用的替代方法。通过使用来自不同植物物种或不同基因变体的GA2ox基因，这种转基因方法实现的小型化可以进一步扩展，从而扩大蝴蝶兰品种小型化的技术平台，以满足微型蝴蝶兰花卉市场的潜在需求。
