Spatial metabolomics as a new avenue in plant developmental biology: insights into serine biosynthesis during spermatogenesis in <i> <b>Marchantia polymorpha</b> </i>

Plant development is a complex process governed by genetic regulatory networks in which metabolites play essential roles by modulating gene expression and cellular processes. While the functional importance of metabolites in plant development is increasingly recognized, their precise spatial and temporal accumulation patterns, which are closely tied to their mechanistic roles, remain poorly understood. This study highlights the need for high-resolution analyses finely tuned to specific developmental processes within the framework of plant developmental metabolomics. Using a <i>Marchantia polymorpha</i> mutant lacking 3-phosphoglycerate dehydrogenase (PGDH), an essential enzyme in serine biosynthesis and sperm formation, we demonstrated the importance of spatiotemporal metabolomics analysis. Conventional whole-organ metabolomics analysis failed to capture the difference between wild-type and mutant plants. Despite its limited resolution, however, spatial metabolomics analysis detected local metabolic changes caused by the mutation. Our results highlight the necessity of focusing on local metabolic alterations to better understand the influence of metabolism on plant development. This study illustrated how high-resolution spatial metabolomics analysis can provide new insights into the metabolic processes underlying plant development. Our findings highlight the need to refine metabolomics tools to better capture the spatial and temporal dynamics of metabolism during plant development, with broad implications for plant biology.