Study On Function Of Flowering Related Genes And Quantitative Analysis On The Dynamic Change Of Endogenous Hormones In Petal Development In Sinningia Speciosa

SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1(SOC1), a critical integrator of different flowering pathways in Arabidopsis, integrates multiple flowering signals derived from the photoperiod pathway, vernalization pathway, the autonomous pathway and gibberellin pathway. We have cloned two SOC1-like genes SsSOC1a and SsSOC1b from Sinningia speciosa. In order to study their functions, the SsSOC1a and SsSOC1b gens were transformed into Sinningia speciosa and tobacco by Agrobacterium-mediated method. Meanwhile, quantitative analysis on the dynamic changes of four endogenous hormones in petal development of Sinningia speciosa was done, which provide a scientific material for the further studying the mechanism of floral organ development. The obtained results are as following:1. The SsSOC1b was transformed into tobacco by Agrobacterium-mediated method, and eight plants of transgenic tobacco were obtained. Compared with wild tobacco, the transgenic tobacco showed two types of significantly different phenotypes.The first phenotype showed that plants height increased significantly, floral buds differentiated and blooming early, floral bud number increased as well. The second phenotype showed that plant height have no obvious difference compared with the wild-type, but there is no floral bud differentiation during the whole life cycle. This indicated that the SsSOC1b not only affects tobacco floral bud differentiation and development, but also affect the development of plant height.2. The SsSOC1a and SsSOC1b were transformed into Sinningia speciosa by Agrobacterium-mediated method, five plants of the transformed SsSOC1a and eight of the transformed SsSOC1b plants were obtained. Phenotypic observations showed that in plants of the transformed SsSOC1a, floral bud differentiation rate after transplanting for48days and58days were61.3%and84.6%respectively. At the same time in the transformed SsSOC1b and wild plants, floral bud differentiation rate was zero. In addition, the plants of the transformed SsSOC1a flowered earlier for10-12days than the wild-type, and flowering time of the transformed SsSOC1b have no significant difference compared with wild-type.3. The changes of endogenous hormone content during petal development in Sinningia speciosa were measured by indirect ELISA (enzyme linked immunosorbent assay). The results show that content of four kinds of endogenous hormones and dynamic changes have obvious difference. Endogenous ABA content was the highest and IAA content was the lowest in the petals; Endogenous ZRs content was lower in early development of petals, and it reached to a small peak in early stage of flowering, then had a slightly decreased in blossom, but in this stage the content still was higher than early petal development; Endogenous IAA content was lower in early development stage of petals, it reached to a low peak in early stage of flowering, then followed by a gradual pick-up, and achieved a maximum value in blossom; Endogenous GA content had a significant fluctuation in the entire petal development process, appeared M-shaped changes, have two peak in the later stage of floral bud and early stage of flowering respectively. Endogenous ABA content had a peak at the end of floral bud development, then declined rapidly, and stably maintain a similar level to the early petal development.