Function Research On ArsKN2 Gene Of Adiantum Reinforme Var.Sinense Y.X.Lin

KNOX genes(KNOTTED1-like homeobox genes) is a homeobox transcriptional factors, consisted of Class I and class II KNOX genes. Class I KNOX genes plays a crucial role in maintenance of cell meristematic activity, class II KNOX genes are mostly expressed in the developed tissues, and can regulate the haploid-to-diploid morphological transition in the moss. A class II KNOX genes has been cloned from Adiantum reniforme var. Sinense before, named as ArsKN2. This study planned to transfer ArsKN2 genes into Arabidopsis thaliana, Nicotiana tabacum and Ceratopteris thalictroides, the main results are shown as follows:1. ArsKN2 over-expression vector pCAMBIA1302-ArsKN2 was transferred into Arabidopsis thaliana through Floral Dip method. When the first flower showed up,the average rosette leaves in transgenic plant is 15.37, and the average number in control plants is 11.63; the days when first flower could be seen in transgenic plant is 34.73,and in control plant is 28.1. Transgenic plants showed significant phenotype of delayed flower time. Compared to control plants, part of transgenic plants has shorter filaments. Except that, there’s no striking difference in plant morphology and the form and color of leaves.Analyzed the expression of the key genes controlling the flowering time in Arabidopsis by real-time quantitative technical. With the rapidly increase of ArsKN2’s expression in floral transition stage of transgenic plants, the expression of AP1 and LFY in trasngenic was significantly lower than control plant. AP1 and LFY act as the marker for the moment of the floral transision and facilitator for floral organ formation. The expression of SOC1 in transgenic plant was slightly lower than control plant, it works as an integrator gene of photoperiod and age pathway and so on. SVP and FLC are two important flowering repressors, the expression of these two genes in transgenic plant was both higher than control plant, but FLC showed more remarkable change. These results suggested that ArsKN2 genes can regulate the expression of the integrator genes to influence the flowering time in Arabidopsis and verified the conclusion that Class II KNOX genes can regulate the haploid-to-diploidmorphological transition in the land plants again.2. Thirty positive trangenic tobacco plants have been verified after ArsKN2over-expression vector pCAMBIA1302-ArsKN2 transferred into tobacco.3. Transformation of Ceratopteris thalictroides using Spores as Targets didn’t get any positive seedlings. This study set different bacteria concentration, infection time and co-culture time, finally, the most appropriate transformation system for spore germenation is OD600 0.4, infection time for 10-15 min, co-culture time for 72 h,undering these conditions, the result showed the germenation rate could reach to 80%.