RT Journal Article
T1 Chloroplast envelope K+/H+ antiporters are involved in cytosol pH regulation
A1 Rodríguez-Rosales, María Pilar
A1 Rubio-Valverde, Lourdes
A1 Pedersen, Jesper
A1 Aranda-Sicilia, María Nieves
A1 Fernández, J.A.
A1 Venema, Kees
K1 Cloroplastos
K1 Células vegetales
K1 Arabidopsis thaliana
AB Variations in light intensity induce cytosol pH changes in photosynthetic tissues, providing a possible signal to adjust a variety of biochemical, physiological and developmental processes to the energy status of the cells. It was shown that these pH changes are partially due to the transport of protons in or out of the thylakoid lumen. However, the ion transporters in the chloroplast that transmit these pH changes to the cytosol are not known. KEA1 and KEA2 are K+/H+ antiporters in the chloroplast inner envelope that adjust stromal pH in light-to-dark transitions. We previously determined that stromal pH is higher in kea1kea2 mutant cells. In this study, we now show that KEA1 and KEA2 are required to attenuate cytosol pH variations upon sudden light intensity changes in leaf mesophyll cells, showing they are important components of the light-modulated pH signalling module. The kea1kea2 mutant mesophyll cells also have a considerably less negative membrane potential. Membrane potential is dependent on the activity of the plasma membrane proton ATPase and is regulated by secondary ion transporters, mainly potassium channels in the plasma membrane. We did not find significant differences in the activity of the plasma membrane proton pump but found a strongly increased membrane permeability to protons, especially potassium, of the double mutant plasma membranes. Our results indicate that chloroplast envelope K+/H+ antiporters not only affect chloroplast pH but also have a strong impact on cellular ion homeostasis and energization of the plasma membrane.
PB Wiley
YR 2024
FD 2024
LK https://hdl.handle.net/10630/40132
UL https://hdl.handle.net/10630/40132
LA eng
NO Rodríguez-Rosales MP, Rubio L, Pedersen JT, Aranda-Sicilia MN, Fernández JA, Venema K. Chloroplast envelope K+/H+ antiporters are involved in cytosol pH regulation. Physiol Plant. 2024 May-Jun;176(3):e14376. doi: 10.1111/ppl.14376
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 21 ene 2026