Isolation and characterization of chalcone synthase gene isolated from Dendrobium Sonia Earsakul.

To isolate and characterize chalcone synthase gene in anthocyanin biosynthetic pathway during flower development of Dendrobium Sonia Earsakul. The gene was isolated from floral tissues of the orchid by reverse transcriptase polymerase chain reaction. Characterization of the gene considered to its relatedness to chalcone synthase gene in other orchid plants elucidated by construction of a neighbor-joining phylogenetic tree. Gene expression pattern related to flower development and pigmentation was investigated by relative quantification real time polymerase chain reaction. A complete coding sequence was obtained and sequence analysis revealed that the gene of Dendrobium Sonia Earsakul consisted of 1,188 bp. Blast analysis and multiple alignments showed that the chalcone synthase gene of Dendrobium Sonia Earsakul shares high homology to chalcone synthase gene of Dendrobium genus particularly Dendrobium hybrid Uniwai prince. Phylogenetic tree revealed that chalcone synthase of Dendrobium genus are highly conserved. The chalcone synthase gene of Dendrobium Sonia Earsakul was highly expressed in young flower bud with no pigmentation and the expression was sharply decreased when young flower bud started accumulation of pigments. Expression of chalcone synthase gene was then maintained at the same level until young bud developed into fully opened flowers.

Intracellular and intercellular movement of maize streak geminivirus V1 and V2 proteins transiently expressed as green fluorescent protein fusions.

Transient expression of the maize streak geminivirus virion-sense proteins V1 and V2 (movement protein, MP, and coat protein, CP, respectively) in maize leaves allowed investigation of their roles in inter- and intracellular movement. Bombardment of a construct directing expression of a V1:green fluorescent protein (GFP) fusion product resulted in significantly increased spread of fluorescence from the bombarded cell to adjacent cells compared to that obtained following expression of free GFP. A mutant V1:GFP fusion product exhibited markedly less movement than the V1:GFP protein. Thus, the MSV V1 protein moves from cell to cell in the absence of other viral proteins. However, V1:GFP did not localize to plasmodesmata in maize or tobacco leaves although a tobacco mosaic virus MP:GFP fusion protein was shown to do so in tobacco. The CP:GFP fusion product targeted exclusively to the nucleus and did not move from cell to cell or exit the nucleus when expressed alone. When coexpressed with V1, some CP:GFP fluorescence was seen at the cell periphery in a proportion of cells, but in no case was cell-to-cell movement of CP:GFP detected. The likely roles of V1 and CP in MSV movement are discussed.