TY - JOUR
T1 - K+ and Cl− channels/transporters independently fine-tune photosynthesis in plants
AU - Dukic, Emilija
AU - Herdean, Andrei
AU - Cheregi, Otilia
AU - Sharma, Anurag
AU - Nziengui, Hugues
AU - Dmitruk, Dominika
AU - Solymosi, Katalin
AU - Pribil, Mathias
AU - Spetea, Cornelia
PY - 2019
Y1 - 2019
N2 - In variable light environments, plants adjust light use in photosynthetic electron transport and photoprotective dissipation in the thylakoid membrane. In this respect, roles of the K+/H+ antiporter KEA3, the Cl− channel/transporter CLCe and the voltage-dependent Cl− channel VCCN1 have been unraveled in Arabidopsis thaliana. Here we report that they independently adjust photosynthesis on the basis of analyses using single and higher order loss-of-function mutants. In short experiments of photosynthetic response on transition from dark to low light, we reveal a sequential functioning of VCCN1 and CLCe in the activation of photoprotection and of KEA3 in its downregulation to a low steady state while adjusting the electron transport. On transition from low to high light, VCCN1 accelerates the activation of photoprotection, whereas KEA3 slows it down on transition from high to low light. Based on parallel electrochromic band shift measurements, the mechanism behind is that VCCN1 builds up a pH gradient across the thylakoid membrane, whereas KEA3 dissipates this gradient, which affects photoprotection. CLCe regulates photosynthesis by a pH-independent mechanism likely involving Cl− homeostasis. Nevertheless, all genotypes grow well in alternating high and low light. Taken together, the three studied ion channels/transporters function independently in adjusting photosynthesis to the light environment.
AB - In variable light environments, plants adjust light use in photosynthetic electron transport and photoprotective dissipation in the thylakoid membrane. In this respect, roles of the K+/H+ antiporter KEA3, the Cl− channel/transporter CLCe and the voltage-dependent Cl− channel VCCN1 have been unraveled in Arabidopsis thaliana. Here we report that they independently adjust photosynthesis on the basis of analyses using single and higher order loss-of-function mutants. In short experiments of photosynthetic response on transition from dark to low light, we reveal a sequential functioning of VCCN1 and CLCe in the activation of photoprotection and of KEA3 in its downregulation to a low steady state while adjusting the electron transport. On transition from low to high light, VCCN1 accelerates the activation of photoprotection, whereas KEA3 slows it down on transition from high to low light. Based on parallel electrochromic band shift measurements, the mechanism behind is that VCCN1 builds up a pH gradient across the thylakoid membrane, whereas KEA3 dissipates this gradient, which affects photoprotection. CLCe regulates photosynthesis by a pH-independent mechanism likely involving Cl− homeostasis. Nevertheless, all genotypes grow well in alternating high and low light. Taken together, the three studied ion channels/transporters function independently in adjusting photosynthesis to the light environment.
UR - http://www.scopus.com/inward/record.url?scp=85067354548&partnerID=8YFLogxK
U2 - 10.1038/s41598-019-44972-z
DO - 10.1038/s41598-019-44972-z
M3 - Journal article
C2 - 31201341
AN - SCOPUS:85067354548
SN - 2045-2322
VL - 9
SP - 1
EP - 12
JO - Scientific Reports
JF - Scientific Reports
M1 - 8639
ER -