Analysis Of The Gibberellin Metabolic Key Genes Expression In Different Reproductive Types Of Boehmeria Tricuspis (Hance) Makino

Gibberellin as an important endogenous hormone in plants is important in growth development, male flower differentiation and so on. The recent researches indicated that gibberellin has some function in apomixis. The research is based on collected Boehmeria tricuspis( Hance) Makino, firstly us ing flow cytometry to detect chromosome ploidy and analysis the reproductive types of B. tricuspis. Then using the real-time fluorescent quantitative PCR to analysis of the GAs metabolic key genes expression in different ploidy of B. tricuspis. And discuss the influence of GAs to floral development and apomixis, which provides reference to study genetic basis of apomixis and explore molecular mechanism in B. tricuspis.The research of chromosome ploidy and reproductive types in B. tricuspis by using flow cytometry indicates that the Galbraith isolation buffer is the best for the seeds of B. tricuspis. There have diploid, triploid and tetraploid in B. tricuspis, and diploid has two types: sexual reproduction and facultative apomixis, triploid is obligative apomixis and tetraploid is facultative apomixis. We detected the tetraploidy B. tricuspis for the first time and identificated its reproductive type.In the research of genes expression analysis, firstly we extracted the total RNA of leaves and inflorescences from B. tricuspis using improved method of CTAB and reverse transcript to c DNA. Then We found 19 Unigene( 5 BtGA2 ox genes, 2 BtGA20 ox genes, 3 BtGA3 ox genes, 3 Bt DELLA genes, 3 BtGASA genes and 2 BtGID1 genes) related with GAs metabolism from transcriptome annotations of B. tricuspis and designed their primers. Analysis of the expression of genes in different development stages of leaves and inflorescences that from different reproductive types of B. tricuspis by using real-time fluorescent quantitative PCR. The results indicate:1. On the vegetative growth stage, unlike other 3 germplasm materials, the non-flowering mutant of B. tricuspis has high relative expression of BtGA2 ox,BtDELLA genes and low relative expression of BtGA20 ox, BtGA3 ox, BtGID1 genes, which decreased the content of active GAs seriously. These may led to dwarf plant and undifferentiated male flowers in B. tricuspis.2. In the inflorescences of apomictic plants, the expression of BtGA20ox-1 and Bt GA3 ox genes were signif icantly increased in the stage of flower bud I and the expression of Bt GID1-1 gene was corresponding increased, which indicates the content of GA was increasing and signal trans duction was enhancing. These promoted the development of diplospory in apomictic plants.3. In apomictic plants, the relative expression of BtGASA-2,BtGASA-3 genes were high in inflorescences while low in leaves on every stages. And the relative expression of Bt GASA genes were low in leaves and inflorescences on every stages from sexual diploid. Which indicated BtGASA-2 and BtGASA-3 genes were likely to be associated with the development of the apomictic flowers.