Discovery of synthetic small molecules that enhance the number of stomata: C-H functionalization chemistry for plant biology.

The increasing climate changes and global warming are leading to colossal agricultural problems such as abatement of food production and quality. As stomatal development is considered to play a key role in crop plant productivity and water-use efficiency, studying stomatal development is useful for understanding the productivity of plant systems for both natural and agricultural systems. Herein, we report the first-in-class synthetic small molecules enhancing the number of stomata in Arabidopsis thaliana that have been discovered by screening of the chemical library and further optimized by the Pd-catalyzed C-H arylation reaction. The present study shows not only huge potential of small molecules to control the cellular and developmental processes of stomata without using genetically modified plants, but also the power of C-H functionalization chemistry to rapidly identify the optimized compounds.