Stomata are microscopic valves on the plant epidermis that played a critical role in the evolution of land plants. Studies in the model dicot Arabidopsis thaliana have identified key transcription factors and signaling pathways controlling stomatal patterning and differentiation. Three paralogous Arabidopsis basic helix-loop-helix proteins, SPEECHLESS (SPCH), MUTE, and FAMA, mediate sequential steps of cell-state transitions together with their heterodimeric partners SCREAM (SCRM) and SCRM2. Cell–cell signaling components, including putative ligands, putative receptors, and mitogen-activated protein kinase cascades, orient asymmetric cell divisions and prevent overproduction and clustering of stomata. The recent availability of genome sequence and reverse genetics tools for model monocots and basal land plants allows for the examination of the conservation of genes important in stomatal patterning and differentiation. Studies in grasses have revealed that divergence of SPCH-MUTE-FAMA predates the evolutionary split of monocots and dicots and that these proteins show conserved and novel roles in stomatal differentiation. By contrast, specific asymmetric cell divisions in Arabidopsis and grasses require unique molecular components. Molecular phylogenetic analysis implies potential conservation of signaling pathways and prototypical functions of the transcription factors specifying stomatal differentiation.
On behalf of the New Phytologist Trust and symposium organisers, I am pleased to invite you to ‘Stomata 2020’, which will take place at the New Century Grand Hotel Kaifeng, China, 11–14 September 2020.
Stomata (singular, “stoma”) are tiny pores through which plants breathe. Stomata are found on the upper and lower sides of leaves, on flower petals, on stems, and on roots.
Scientists survey plant surfaces to determine the density and size of stomata and relate these findings to properties of the environment, such as temperature and the amounts of sunlight, humidity, oxygen, and carbon dioxide in the air when a leaf is formed.
Stomata of various plants are suitable subjects for classroom laboratory activities since they may be examined by light microscopy.
A total of 40 angiosperm plant species from 38 genera of 22 families were investigated for the type and shape of leaf epidermal cells.
The result showed substantial variations in the type and shape of epidermal cells from straight to polygonal up to wavy. The present results showed that the shape of leaf epidermal cells can not play its role in correlating the taxa but is significant in delimiting the related taxa.