Virus-induced Gene Silencing As A Tool For The Founctional Of Several Floral Homeotic Genes In Pisum Sativum

We used a pea early browning virus (PEBV)-based VIGS approach to study the function of several floral homeotic genes in Pisum sativum. We choosed 5'nucleotide sequences coding region corresponding to MADS box of the PEAM4, PsPI, PsAG, PsSEP1/2,which respectively belong to the A.B.C and E class gene for the constructing of the VIGS vector. The results of construction of the conserved MADS-box gene segment for VIGS suggest that it is possible to study one kind of homologues' function through silencing the highly conservative gene segment.In addition, we also produced another VIGS constructs for PEAM4 and PsFUL, which are APETALA1/FRUITFULL-Like gene family members. we choosed the conserved gene segment of PsFUL to construct the VIGS vector and find that it is not relatively silent phenotype in this VIGS construct.At the same,we choose the conserved gene segment and the specific gene segment of the PEAM4 for the constructing of the VIGS vector respectively naming them as PEAM4C and PEAM4S. Both of the two construct show their mutant pim's phenotype. The pim mutants include pim-1 and pim-2 mutations, which delayed floral meristem specification and altered floral morphology significantly and are similar to that of ap1 mutants in Arabidopsis. Rearch show that the emerging floral meristems require AP1 to partly specify their floral identities by directly repressing a group of flowering time genes, including SHORT VEGETATIVE PHASE (SVP), AGAMOUS-LIKE 24 (AGL24) and SUPPRESSOR OF OVEREXPRESSION OF CO1 (SOC1). In wild-type plants, these flowering time genes are normally downregulated in emerging floral meristems. In the absence of AP1, these genes are ectopically expressed, transforming floral meristems into shoot meristems.Here we virified that PsSOC1 and PsSVP are ectopically expressed in the background of silencing of PEAM4 in pea by using Real-time PCR and mRNA in situ hybridization.