Stomata

Abstract As adjustable pores, each delimited by a pair of guard cells, stomata are central determinants of plant photosynthesis, transpirational cooling and ecological adaptability, which have huge impact on global water and carbon cycles, plant competitiveness and nutrients in foods. The specialised guard cell anatomy and membrane ion transport enable plants to adapt stomatal aperture rapidly to hormone and environment changes. In contrast to the highly conserved simple structure across land plants, the stomatal size, density and distribution patterns vary substantially among species or genotypes within a species providing ample genetic resources on which selection can operate. Study of the development and function of stomata is crucial to understand cell fate specification, signal transduction and plant–environment interactions and inform approaches to breed ‘climate change ready’ crop varieties with improved agricultural capacity and food nutrients. Key Concepts Stomata and active stomata control are a key evolutionary innovation vital for plants to survive and thrive on land. Plants use stomata for gas exchange, water regulation, mineral transport, spore dispersal and pathogen defence. Plants produce stomata in organised patterns and in environmentally optimised numbers. Stomata vary widely in size and responsiveness among species or genotypes within a species. The specialised guard cell morphology, anatomy and membrane ion transport enable plants to adapt stomatal aperture rapidly to hormone and environment changes. Stomata have major influence on the growth and fitness of land plants and global environment as well as food security. Revealing the molecular nature of stomatal regulators will inform us the approaches to breed climate resilient crops.