Primary Phenotype Analysis Of Developmental Retardation In Arabidopsis Mutant Sic1-1

Cell division is the basis of plant growth and development, which can be significantly affected by cell cycle. Using a T-DNA gene-trap system, our lab isolated a mutant, sic1-1, in Arabidopsis thaliana T-DNA mutant library. Sic1-1has dwarf phenotype and shorter primary root. More importantly, sic1-1is stunteder than wild type in the temperature of17℃compared to22℃and27℃. We analyzed the nucleus DNA ploidy of first pair leaves of sicl-1at series of developmental periods, our results show that, compared with wild type, sicl-1has more cells with low DNA ploidy. Simultaneously, our results show that, more immature epidermal cells can be observed in sic1-1. We calculated the root cortical cell production rate and detected the CYCB1:GFP expression in root tip of sicl-1, our results show that the rate of cell production is decreased and CYCB1accumulation is abnormal. Meanwhile, we analyzed the nucleus DNA ploidy of first pair leaves, cotyledons and roots of sic1-1at different temperature conditions, results show that the percentage of low DNA ploidy cells decreased of both sic1-1and wild type as the temperature increases. But compared with wild type, sic1-1has more cells with low DNA ploidy at the same condition. We also analyzed epidermal cells of first pair leaves at different temperature conditions, our results show that more immature epidermal cells can be observed in sicl-1and wild type at low temperature condition, but sicl-1has more immature epidermal cells at the same condition. The embryonic development of sic1-1is delayed. These results reveal that sicl-1is developmental retardation, which may be related with the abnormal accumulation of CYCB1and cell division, and show that the SIC1plays an important role in cell cycle and plant development.