A Pollen Carbonic Anhydrase Promotes Male Fertility Under Elevated Carbon Dioxide in Tomato
Jianrong Lv, Haiming Ying, Chenxin Yue, Zhengran Zhao, Shurong Wu, Rui Deng, Wenshan Zai, Cunnian Fu, Huan Liu, Christine H. Foyer, Kai Shi, Anran WangABSTRACT
Rising atmospheric CO 2 is a defining feature of climate change and profoundly influences plant growth and productivity. While the effects of elevated CO 2 on photosynthesis and vegetative biomass have been extensively studied, its direct impact on male reproductive development remains poorly understood. Here, we show that elevated CO 2 improves pollen vigour and performance in tomato ( Solanum lycopersicum ). Through genetic and molecular analyses, we identify β‐type carbonic anhydrase 2 (βCA2) as a pollen‐enriched CO 2 sensor required for this response. Loss of βCA2 abolishes the promoting effects of elevated CO 2 on fertility, whereas βCA2 overexpression mimics the high‐CO 2 phenotype under ambient conditions. Further analyses revealed that βCA2 regulates downstream networks involved in vesicle trafficking and intracellular transport to promote pollen germination, alongside cellulose and pectin metabolism required for pollen intine remodelling. These findings suggest a potential link between βCA2 ‐mediated CO 2 perception, intracellular transport and pollen intine remodelling. Our results uncover a dynamic, pollen‐specific CO 2 response pathway that integrates intracellular transport with structural wall remodelling, providing new insights into how plants sustain male fertility under rising atmospheric CO 2 .