An effective homologous cloning method for isolating novel miR172s from phalaenopsis hybrida

Abstract

MiR172is an important microRNA that regulates floral development in various plants and downregulates AP2family members to relieve the stress on floral determinacy, leading to phase transition from vegetative to reproductive growth. In this work, PCR with primers designed based on the rice miR172 sequence was used to isolate two miR172-like transcripts from Phalaenopsis hybrida(PhmiR172-1and PhmiR172-2) that were very similar to Oryza miR172dandArabidopsis miR172b. RT-PCR indicated that the levels of these two transcripts were negatively correlated with the level of the Phalaenopsis AP2(PhAP2) gene in stem, root, pedicel and sepal, and that both were co-expressed with PhAP2in young buds. Overproduction of PhmiR172-2i n Arabidopsisled to early flowering. The homologous cloning method usedtoisolate thePhalaenopsis miR172-like transcripts can be used toisolate miRNAs from other species. These PhmiR172transcripts may be used to accelerate the flowering of orchids.