Update: Transitory starch metabolism in guard cells: unique features for a unique function

In leaf mesophyll cells, some of the sugars produced by photosynthesis are stored as transitory starch, which is then broken down to provide the cells with energy during the night. Recent advances in imaging and staining and the use of mutants have enabled the pattern of accumulation of transitory starch in guard cells to be determined. Santelia and Lunn review these new insights and the special role of starch catabolism products (including malate) in stomatal opening in the light. The authors conclude, “Our aim in this review has been to highlight the exciting recent advances in our understanding of guard cell metabolism, with the hope of persuading young researchers to fall in love with stomata, and take up the challenge to explore their fascinating biology.” Plant Physiol. 10.1104/pp.17.00211