THE SEEDLING GROWTH (SG) SERIES OF PLANT BIOLOGY EXPERIMENTS IS PART OF A BARTER AGREEMENT BETWEEN NASA AND ESA. THE MAJOR GOALS ARE: (1) TO DETERMINE HOW GRAVITY AND LIGHT RESPONSES INFLUENCE EACH OTHER IN PLANTS (2) TO BETTER UNDERSTAND THE CELLULAR SIGNALING AND RESPONSE MECHANISMS OF PHOTOTROPISM AND OF LIGHT STIMULATION AND (3) TO STUDY THE FACTORS AFFECTING THE PROLIFERATION AND GROWTH OF MERISTEMATIC CELLS IN ORDER TO ANALYZE IN HOW AUXIN (I.E. A PLANT HORMONE) TRANSPORT AND PERCEPTION ACT IN THE REGULATION OF THESE CELLULAR FUNCTIONS. IN SG WE HAVE BEEN USING THE EUROPEAN MODULAR CULTIVATION SYSTEM (EMCS) WHICH ARGUABLY HAS BEEN ONE OF THE MOST SUCCESSFUL LIFE SCIENCE RESEARCH FACILITIES ON THE ISS. THREE TYPES OF DATA ARE TO BE OBTAINED FROM THE SG EXPERIMENTS: IMAGE DOWNLINKS OF PLANT SEEDLINGS SEEDLINGS FROZEN ON-ORBIT AND SEEDLINGS FIXED IN ALDEHYDES. DOWNLINKED IMAGES PROVIDE DATA ON GERMINATION GROWTH DEVELOPMENT AND TROPISTIC CURVATURE. FROZEN SEEDLINGS WILL BE USED FOR GENE PROFILING STUDIES AND SEEDLINGS FIXED IN ALDEHYDES WILL BE USED FOR HIGH-RESOLUTION ELECTRON MICROSCOPIC ANALYSES.