Effects of root-specific activation of plasma membrane H+-ATPase 1 on genome-wide gene expression in A. thaliana roots

Plasma membrane (PM) H+-ATPase contributes to nutrient uptake and stomatal opening by creating proton gradient across the membrane. A dominant mutation in the OPEN STOMATA2 locus (OST2-2D) constitutively activates Arabidopsis PM H+-ATPase 1 (AHA1), enlarging proton motive force for root nutrient uptake. However, the stomatal opening is also constitutively enhanced in the ost2-2D, which results in drought hypersensitivity. Therefore, we postulated that the root-specific activation of OST2/AHA1 could be an ideal design for improving nutrient uptake efficiency without causing drought hypersensitivity. Accordingly, we grafted Col-0 (WT) scions onto rootstock originating from WT or ost2-2D and analyzed the vegetative growth, nutrient element content, and transcriptomes of the grafted plants grown under nutrient-rich or -poor conditions.