During germination, the embryo within a seed must develop into a young seedling capable of photosynthesis in less than 48 hours. During this time, it relies solely on its internal reserves, which are quickly consumed. It must therefore rapidly create functional chloroplasts, cellular organelles that will enable it to produce sugars to ensure its survival. Researchers from the University of Geneva (UNIGE) and the University of Neuchâtel (UniNE), Switzerland, have revealed in the journal Current Biology the key elements that control the formation of chloroplasts from proplastids, hitherto poorly studied organelles. Such a mechanism ensures a rapid transition to autonomous growth, as soon as the seed decides to germinate.