Functional Analysis Of PsnOBP1 On The Secondary Growth Of Transgenic Tobacco

OBP1 (OBF binding protein) is Dof (DNA binding with one finger) transcription factor, belongs to zinc finger protein superfamily (zinc finger super-family) member of a class of plant-specific transcription factors. OBP1 transcription factors can participate in the growth process of plant development through regulation of cell cycle genes. This study was cloned from Populus (Populus simonii × P nigra) in the full-length cDNA sequence OBP1, because of its similarity with the Arabidopsis OBP199%, hence the name PsnOBP1. By PsnOBP1 basic characteristics and overexpression major tobacco growing and Secondary character analysis, the following conclusions.(1) PsnOBP1 gene encodes a 248 amino acids, the molecular weight of 25.5 kDa, an isoelectric point of 8.57, belonging to the zinc finger protein superfamily Dof transcription factors.(2) PsnOBP1 tissue specific expression studies show, PsnOBP1 gene was expressed in various tissues in Populus, but at a very high expression of xylem, followed by root and leaf tissue. Expression of onion epidermal cells transiently found, PsnOBP1 encoded protein is localized in the nucleus. Using yeast one-hybrid binding capacity of PsnOBP1 transcription analysis showed PsnOBP1 with secondary cell wall formation genes (such as MYB61, MYB63, MYB43, MYB92) in the promoter region of high frequency components GA-motif, GARE-motif, TCA and HSE binding.(3) Overexpression of tobacco PsnOBP1 Main Growth Characters and Secondary trait analysis showed that compared with the wild type, transgenic lines of stem strength, chlorophyll content, fiber length and width and cellulose content increased significantly, significantly increased the secondary cell wall thickness, the lignin content was significantly decreased; secondary cell wall formation of transgenic plants expressing genes related functions have undergone varying degrees of change, wherein the cellulose (CesA4, CesA7, CesA8), hemicellulose formed gene (CesA4, CesA7, CesA8) the expression was significantly up-regulated genes and lignin formation (IRX8,IRX9, FRA8) down-regulated expression; transgenic plants normal growth and development, normal flowering and fruiting, and the height, diameter and biomass compared to wild type, no significant difference.(4) Arabidopsis mutants AtOBP1 Secondary Traits:None compared with normal wild-type Arabidopsis plant height and leaf size significantly, Stem staining, AtOBP1 Arabidopsis mutant to wild-type compared to darken the area of cellulose dyeing, dyeing lignin darker area.