SUMMARY As global climate change intensifies, the resultant increase in atmospheric vapor pressure deficit (VPD) significantly affects plant growth and distribution. Under high VPD (HVPD) conditions, plants face a contradiction between increased water evaporation and carbon fixation. A reduction in stomatal conductance ( g s ) can lead to carbon starvation, causing cellular damage or even death. Aquaporins, which are pivotal in water transport, play a crucial role in modulating plant water balance and g s under HVPD conditions; however, the underlying mechanisms remain inadequately understood. Tomato ( Solanum lycopersicum L.) is an important economic crop. This study found that SlTIP2;3 is a key hub for tomato's response to HVPD and regulation of whole‐plant hydraulic conductance ( K plant ) and g s . The overexpression of SlTIP2;3 was observed to increase K plant and g s under HVPD, enhancing water transport and mitigating the decline in g s . Additionally, the overexpression of SlTIP2;3 improved root and stem morphology, optimizing water absorption and distribution. In this context, SlTIP2;3 , as a hydrogen peroxide (H 2 O 2 ) transporter, facilitates H 2 O 2 diffusion into cells, regulating gibberellin (GA) synthesis and signaling, thus enhancing both K plant and g s . This study presents novel evidence indicating that SlTIP2;3 plays a mediating role in the H 2 O 2 –GA signaling pathway, which co‐regulates plant adaptation to HVPD environments and contributes to maintaining high K plant and g s . These findings provide valuable molecular insights into plant responses to climate change‐induced water stress and support the genetic enhancement of drought‐resistant crops.
Li et al. (2026) studied this question.