Effects Of PhDHS Silencing On Petunia Leaves

DHS is an important modification enzyme that forms the hydroxyl putrescine lysine(hypusine) residuesas of eukaryotic translation initiation factor e IF-5A and it plays an indispensable role in the biological functions of e IF5 A. Another important modification enzyme is DOHH. The biological functions of DHS are mainly involved in cell proliferation, cell apoptosis, m RNA transcription, etc, but the specific function in plants has not been reported in the system. Petunia flowers has served as a model for the study of flowers' s function. In this study, one PhDHS, one DOHH, and three e IF5 A 3‘UTR sequences in petunia were cloned and taking ph CHS as a reporter gene and their silencing vectors were successfully constructed. Therefore, this study uses the constructed vectors and the VIGS technology to silence these target gene. and to further study the function of PhDHS. The results are as follows:(1) By silencing of PhDHS, plants showed chlorotic phenotype and young leaves is more obvious. Chlorophyll content and carotenoid content were reduced, and chlorotic phenotype gradually restored with leaves gradually growth and development.(2) Silencing of PhDHS, delayed the leaf senescence. The expression of PhDHS in older leaves was high in the fluorescence quantitative expression results of wild-type leaves.(3) The leaf cell size and shape changes and the number of chloroplast reduced in PhDHS-silenced plants. Chloroplast structure was not complete and starch grains disappear. The number of granum thylakoids reduced, arranges in disorder, loose and stroma thylakoids is missing.