A review of guard cell wall architecture in shaping stomatal morphology and function

Stomata serve as essential gateways for gas exchange and water loss, accounting for over 90% water loss through transpiration. Therefore, modulating stomatal movement and development is a key strategy for improving crop water-use efficiency (WUE) and drought tolerance. Emerging evidence highlights the critical role of guard cell wall (GCW) composition and modifications in shaping stomatal morphology and modulating stomatal responses to environmental cues, thereby significantly affecting plant WUE, drought resistance, and photosynthetic performance. This review systematically summarizes recent progress in the regulation of GCW components and their modifications. Furthermore, we discuss the potential involvement of transcriptional cascades and cell wall integrity (CWI) sensing pathways in controlling stomatal morphology and dynamics. These insights offer a theoretical basis for the targeted genetic manipulation of GCWs to concurrently enhance crop WUE and drought resilience.