Constitutive Expression Of GhMADS3 Gene Influenced Floral Organ In Transgenic Tobacco

As an important transcription factor, MADS-box protein plays an important role in various cellular processes, especially in regulation of floral organ development. The genes related to this identity are conserved MADS-box genes whose name initially came from the first letter of MCMl(from yeast), AGAMOUS (from Arabidopsis), DEFICIENS (from Antirrhinum) and SRF(from human). The MADS region linked specifically to the coalescent site of target gene and formed a homogenous or heterogenous dimer to regulate it, which can make different kinds of floral organs for many flowering plants. So they are important factors to control the development of floral organs and to make homeotic transformations. It is very useful to analyze the floral organ identity genes in order to understand the molecular model of plant floral organ development .Through plenty of research of the floral organ mutant, Coen developed the "ABC" model about floral organ.The model told us that the floral organ determined by three various genes(A,B,C) which have different functions: A acts in whorls(sepal), A and B function in primarily in whorls 2(petal), B and C in whorls 3(stamen), C determine the form of carpel. In order to explain the homeotic phenotypes caused by mutations in these genes, it proposed that A and C functions are antagonistic such that A function prevents the action of C in whorls 1 and 2, whereas C function prevents the action of A in whorls 3 and 4,and B functions in whorls 2 and 3 and have a independence relationship with A and B.Sequence analysis of GhMADS3 shows that the deduced GhMADS3 protein was highly homologous to the AG-typed-MADS proteins. Phylogenetic analysis also indicates that GhMADS3 belongs to the MADS-box protein of type-AG. The MADS box (l-63aa) is in the N-end and the K box (90-160aa) in the middle. The I region (intervening region) is between the MADS box and the K box which encodes keratin-like protein structure and it is very important to make heterogenous dimer of two MADS box genes. The C-end is a non-conserved region and its function is not very clear. GhMADS3 was transferred into tobacco and observed the influence of floral organ. In order to research the function of GhMADS3,we introduced GhMADS3 into tobacco and mediated by...