Isolation And Functional Confirmation Of DhLHY Of A Doritaenopsis Hybrid Involved In The Regulation Of Flowering

Doritaenopsis, a perennial epiphytic herbaceous flower that belongs to Orchidaceae,are intergeneric hybrids between the Phalaenopsis and Doritis. Due to the butterfly flowershapes, bright colors,3~4months flowering period, and their relatively high economicvalue, these hybrids enjoy a reputation of “Queen” in the LAN and are becoming one ofthe most widely cultivated orchid types.Firstly, LHY related sequences were searched and analyzed from the Phalaenopsislibrary. Then the full length measurement were carried out by PCR gene cloningtechnology to the cDNA of DhLHY gene of ‘Tinny Tender’(Doritaenopsis ‘Happy smile×Happy valentine’), which was used as a test material. It was found that DhLHY cDNA was2,594bp long with a1,962bp open reading frame and encodes653amino acids. Secondly,the abudance of DhLHY mRNA transcript was analysed by quantitative real-time PCR inroots, stems, and leaves under both low and high temperatures. The results showed that theexpression of DhLHY has a24-h rhythms, which reached a peak after exposed in2hoursafter lighting and slowed down at the dusk; DhLHY expression was detected in roots, stemsand leaves, showing a constitutive expression in different tissues during the wholevegetative stages; but in the low temperature treatment, the expression of DhLHY washigher than that of high temperature treatment. Thirdly, DhLHY was transformed intoArabidopsis thaliana by a floral dipping method. to by. Based on the observation ofphenotypic changes, it was found that the flowering time of the DhLHY transgenic plantsdelay by various degree, and the expression of the DhLHY can be detected in the transgenicplants at DNA and RNA levels, similar results of which are found in previous studies.This study is of particular importance to artificial control of Phalaenopsis floweringtime to break the bottleneck of the temperature limit of Phalaenopsis via geneticengineering means, and to progress sustainable development of the Phalaenopsis industry.Moreover, since there has been relatively little study on the molecular research ofPhalaenopsis, to a certain degree, this study is a forward-looking and innovativecontribution to better understanding the molecular mechanism of Phalaenopsis and hasgreat potential for research work and marketing prospects.