Abstract
Polyamines are small polycations observed in various organisms including plants. Genetic analyses using series of Arabidopsis mutants of polyamine biosynthetic genes have helped to clarify the polyamine functions for a variety of physiological processes such as stress response, seed development and stem elongation. In this study, we analyzed a candidate protein involved in Arabidopsis Polyamine Transport system (AtPTP) and characterized the atptp mutant. Comparing to bacteria polyamine transporter proteins, AtPTP has extra sequences in N-terminal region. AtPTP-GFP fusion protein was targeted to the chloroplast and localized in particulate structures. The atptp leaf showed albino phenotype and atptp seed was dark brown and shriveled. Electro microscope observation analysis of atptp seedling showed that level of storage proteins and lipids were less than that of wild type plants. We will discuss the physiological and biochemical roles of AtPTP for plant development.
