Mesophyll conductance has been increasingly recognized as a limiting-factor for carbon transport and fixation during photosynthetic process. Despite mesophyll conductance performs a significant role in determining photosynthetic and yield potential, its molecular mechanisms are uncertain and controversy. In the present study, the function of a plasma membrane aquaporin SlPIP1;2 in facilitating CO₂ transport across the plasma membrane under contrasting CO₂ concentrations was evaluated, according to the photosynthetic performance of transgenic lines of overexpression and knock-out. The relative importance of PIP-channel in determining membrane permeability and mesophyll conductance is largely depend on the ambient and intercellular CO₂ concentration. Under the current ambient CO₂ concentration, SlPIP1;2 had minor effect on photosynthetic performance. Overexpression of the target gene substantially enhanced CO₂ membrane permeability under CO₂ enrichment, according to the photosynthetic performance: overexpression SlPIP1;2 significantly improved mesophyll conductance and photosynthesis rate, which translated into improvement in crop productivity and water use efficiency. The present results suggested that SlPIP1;2 is potentially involved in facilitating CO₂ transport across the plasma membrane under CO₂ enrichment, which subsequently affect crop productivity and water use efficiency.

叶肉电导已日益被认为是光合作用过程中碳转运和固定的限制因素。尽管叶肉电导在确定光合作用和产量潜力中起着重要作用，但其分子机制仍不确定且存在争议。在本研究中，根据过表达和敲除的转基因株系的光合作用性能，评估了质膜水通道蛋白AβPIP1; 2在不同的CO ₂浓度下促进CO ₂跨质膜运输的功能。PIP通道在确定膜通透性和叶肉电导率方面的相对重要性在很大程度上取决于环境和细胞间的CO₂浓度。在当前环境CO ₂浓度下，SlPIP1; 2对光合性能的影响较小。靶基因的过表达显着增强CO ₂下CO膜渗透性₂富集，根据光合性能：过表达SlPIP1; 2显著改善叶肉电导和光合速率，从而转化为提高作物产量和水分利用效率。目前的结果表明，SlPIP1; 2可能参与促进CO ₂在CO ₂下穿过质膜的运输。 富集，从而影响作物的生产力和水分利用效率。