Shoot Development Programs in Phalaenopsis amabilis Orchid Plant

Abstract

To study the shoot formation in orchid, we analyzed the function of Arabidopsis Class I KNOX genes KNAT1 and a leaf gene ASYMMETRIC LEAVES2 (AS2) under the control of Cauliflower Mosaic Virus 35S RNA promoter in Natural Indonesian orchid, Phalaenopsis amabilis. In this study, those two genes were transformed using Agrobacterium tumefaciens LBA 4404. We got 11 lines of KNAT1 transgenic protocorm (developing orchid embryo) that formed multishoots (4-31 shoots developed from one embryo) and 79 lines of AS2 transgenic orchid plants. Detection of transgenic lines were performed by Kanamycin selective medium and PCR. The shoot formation in 4 lines of KNAT1 transgenic plants showed multishoots and alteration of leaf shapes. P35S::AS2 transgenic plants showed smaller leaf blade with abnormal vascular pattern, and dwarf shoots. Histological analysis of protocorm in KNAT1 transgenic plants showed that shoot initially come from some area in the periphery.