The module of PeGLK1-1–PeWRKY111–PePMHA9 orchestrates stomatal aperture to enhance photosynthetic capacity in bamboo

• The regulation of stomatal aperture is closely related to bamboo photosynthetic capacity. • PePMHA9 participates in photosynthesis by regulating stomatal aperture. • Overexpression or knockdown of PePMHA9 correspondingly alters bamboo photosynthetic capacity. • PeGLK1-1 synergistically interacts with PeWRKY111 to promote PePMHA9 transcription. • PePMHA9 , PeGLK1-1 and PeWRKY111 promote stomatal opening to improve photosynthetic capacity. Global warming, driven by CO 2 emissions, poses a profound threat to the ecosystems and the sustainable development of human society. Bamboo with outstanding carbon sequestration capacity provides natural solutions to mitigate global warming. Stomata govern CO 2 entry from the atmosphere into leaves, enabling plants to conduct photosynthesis. However, the relationship between stomatal aperture regulation and photosynthesis in bamboo remains unknown. To excavate the key genes controlling stomatal aperture and elucidate their molecular mechanism in bamboo photosynthesis. Leaf physiology and stomatal morphology of moso bamboo were analyzed using LI-6800 system and a scanning electron microscope, respectively. Based on the integrated analyses of transcriptome data and physiological indicators, key photosynthesis-related genes were identified. Gene functions were verified through endogenous expression in moso bamboo and ectopic expression in rice. The gene transcriptional regulation was confirmed using molecular biology methods. Higher net photosynthetic rate and stomata-opening ratio were found in the primary functional leaves of moso bamboo. PePMHA9 , which belongs to plasma membrane H + -ATPase family, was identified as a hub gene in regulating stomatal aperture, and its expression in the guard cells of moso bamboo leaves was validated by in situ hybridization. Transient overexpression of PePMHA9 could increase bamboo photosynthetic capacity, whereas its knock-down had an opposite effect. Overexpressing PePMHA9 in rice could promote stomatal opening and improve photosynthetic capacity under high light. Moreover, PePMHA9 co-expressed with PeWRKY111 , and was activated by PeWRKY111. Furthermore, PeGLK1-1 potentiated PePMHA9 transcription by interacting with PeWRKY111. Additionally, PeGLK1-1 and PeWRKY111 shared similar gene expression patterns with PePMHA9 , which jointly enhanced PePMHA9 transcription, thus mediating stomatal opening to improve photosynthetic capacity. PeGLK1-1–PeWRKY111– PePMHA9 module regulates photosynthetic capacity by controlling stomatal aperture in bamboo. These findings provide insights into the regulatory mechanism of bamboo photosynthesis and facilitate germplasm innovation.