Nutrient modulation of Arabidopsis shoot apical meristem dynamics (PNAS)

Proc. Natl. Acad. Sci. USA. The shoot apical meristem (SAM) is essential for the adaptation of aerial plant tissue architecture to changes in the environment. This paper by Landrein and colleagues connects changes in the plant environment (soil type, soil fertility, nitrate concentration) to changes in the SAM, using quantitative microscopy, grafting experiments, and mutant studies in Arabidopsis thaliana. This connection is due to the systemic signal of cytokinin precursors that mediate changes in SAM size and organogenesis rate due to the availability of nutrients. These changes take place through the modulation of WUSCHEL expression, a transcription factor that is key regulator for stem cell homeostasis. For example, the SAM adapts to changes in nitrate concentration by modulating the rate of organ production. This study connects the stem cell regulatory network (i.e. WUSCHEL) to SAM function and adaptation to the environment. (Summary by Julia Miller) Proc. Natl. Acad. Sci. USA.  10.1073/pnas.1718670115