Evolutionary insights into light-induced stomatal opening mechanisms

Light-induced stomatal opening pathways are essential for regulating gas exchange and water loss in response to dynamic environmental light cues. While stomatal signalling pathways are well characterised at the genetic level in Arabidopsis thaliana (arabidopsis), much less is known about these mechanisms in non-flowering plant groups. We discuss recent advances in our knowledge of key components – photoreceptors, mitogen-activated protein kinases (MAPKs), phosphatases, H⁺-ATPases and ion channels – across plant lineages, highlighting the gaps in knowledge particularly in non-flowering species. Addressing these gaps will provide valuable insights into stomatal evolution and a deeper understanding of the functional diversity of the plants alive today.