A plasma membrane H+-ATPase gene (PeA2) is critical for bamboo stomatal opening and photosynthetic ability

Zhimin Gao, Hui Li
Institute of Gene Science and Industrialization for Bamboo and Rattan Resources, International Centre for Bamboo and Rattan, Beijing 100102, China

The leaves are main organs for photosynthesis and different leaf positions can reflect the growth and development characteristics of leaves during spatiotemporal changes. However, the expression pattern of H+ATPase gene and its regulatory mechanism in bamboo leaves at different positions is still unclear. The first to fifth leaves from top to bottom of moso bamboo (Phyllostachys edulis) branches were investigated in this study. The result showed that the chlorophyll content, net photosynthetic rate, stomatal conductance, and percentage of open stomatal were first increased and then decreased from the first to fifth leaves, while the trend of intercellular CO2 concentration was opposite. Based on the WGCNA of transcriptome data from leaves at different positions combined with physiological characteristics, a plasma membrane H+-ATPase gene (PeA2) related to stomatal opening and photosynthetic ability was selected for further analysis. PeA2 was most highly expressed in the third leaf and co-expressed with PeWRKY111. PeWRKY111 could activate PeA2 which was validated by Y1H, DLR, and GUS assays. In-planta gene editing of PeA2 led to decreased photosynthetic ability, while its transient overexpression resulted in increased photosynthetic ability of bamboo leaves. This study provided a basis for elucidating the mechanism of PeA2 in bamboo photosynthesis.