Project description:Plasma membrane proton pump maintains proton electrochemical gradient and provides energy to secondary transporters. Arabidopsis mutant plants with reduced proton pump activity grow normal under ideal growth conditions; however their growth are reduced compared with wildtype plants when placed under the conditions that stress on protonmotive force (high external pH or high external potassium).
Project description:Plasma membrane proton pump maintains proton electrochemical gradient and provides energy to secondary transporters. Arabidopsis mutant plants with reduced proton pump activity grow normal under ideal growth conditions; however their growth are reduced compared with wildtype plants when placed under the conditions that stress on protonmotive force (high external pH or high external potassium). Seedlings of wildtype, aha1, and aha2 mutant plants were grown under ideal growth condition. Total RNA from those seedlings were subjected to transcriptome analyses using Affymetrix Gene Chip.
Project description: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.
