ALL FLOWERING PLANTS PRODUCE FLOWERS AND SEEDS THROUGH THE SUCCESSFUL TRANSITION FROM VEGETATIVE TO REPRODUCTIVE GROWTH. WHILE ENORMOUS PROGRESS HAS BEEN MADE TO UNDERSTAND THE MOLECULAR BASES CONTROLLING FLOWERING, IT IS STILL POORLY UNDERSTOOD WHY SOME PLANTS MAINTAIN INDETERMINATE STEM GROWTH WITHOUT TERMINAL FLOWERING, WHEREAS OTHERS PRODUCE BOTH TERMINAL AND LATERAL FLOWERS IN EITHER SYNCHRONIZED OR NON-SYNCHRONIZED MANNERS. IN SOYBEAN STEM GROWTH HABIT IS OF PARTICULAR IMPORTANCE AS IT AFFECTS THE PLANT'S ENVIRONMENTAL ADAPTABILITY AND PRODUCTIVITY, AND IT IS THUS CRITICAL FOR SOYBEAN BREEDERS TO UNDERSTAND THE GENES, GENE NETWORKS, AND NATURAL ALLELIC VARIATIONS FOR THIS KEY TRAIT IF THEY ARE TO CONTINUE DEVELOPING SOYBEAN CULTIVARS WITH BETTER RESILIENCE TO CHANGING ENVIRONMENTS. THIS PROJECT IS BUILT ON OUR PREVIOUS DISCOVERY OF MAJOR GENES AND ALLELIC VARIATIONS MODULATING STEM GROWTH HABIT TO FURTHER REVEAL NOVEL GENETIC AND MOLECULAR MECHNISMS MODULATING SEMI-DETERMINATE STEM GROWTH HABIT IN SOYBEAN. WE ANTICIPATE THAT THE PROPOSED WORK IN THIS PROJECT WILL PROVIDE NOVEL INSIGHTS INTO THE MECHANISMS MODULATING SEMI-DETERMINACY AND PAVE NEW STRATEGIES FOR OPTIMIZING PLANT ARCHITECTURE OF SOYBEAN, AND POTENTIALLY OTHER LEGUME CROPS FOR ENHANCED ENVIRONMENTAL RESILIENCE AND YIELD POTENTIAL.