TY - JOUR
T1 - Functional redundancy between flavodiiron proteins and NDH-1 in Synechocystis sp. PCC 6803
AU - Nikkanen, Lauri
AU - Santana Sánchez, Anita
AU - Ermakova, Maria
AU - Rögner, Matthias
AU - Cournac, Laurent
AU - Allahverdiyeva, Yagut
N1 - Publisher Copyright:
© 2020 The Authors. The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.
PY - 2020/8/1
Y1 - 2020/8/1
N2 - In oxygenic photosynthetic organisms, excluding angiosperms, flavodiiron proteins (FDPs) catalyze light-dependent reduction of O2 to H2O. This alleviates electron pressure on the photosynthetic apparatus and protects it from photodamage. In Synechocystis sp. PCC 6803, four FDP isoforms function as hetero-oligomers of Flv1 and Flv3 and/or Flv2 and Flv4. An alternative electron transport pathway mediated by the NAD(P)H dehydrogenase-like complex (NDH-1) also contributes to redox hemostasis and the photoprotection of photosynthesis. Four NDH-1 types have been characterized in cyanobacteria: NDH-11 and NDH-12, which function in respiration; and NDH-13 and NDH-14, which function in CO2 uptake. All four types are involved in cyclic electron transport. Along with single FDP mutants (∆flv1 and Δflv3) and the double NDH-1 mutants (∆d1d2, which is deficient in NDH-11,2 and ∆d3d4, which is deficient in NDH-13,4), we studied triple mutants lacking one of Flv1 or Flv3, and NDH-11,2 or NDH-13,4. We show that the presence of either Flv1/3 or NDH-11,2, but not NDH-13,4, is indispensable for survival during changes in growth conditions from high CO2/moderate light to low CO2/high light. Our results show functional redundancy between FDPs and NDH-11,2 under the studied conditions. We suggest that ferredoxin probably functions as a primary electron donor to both Flv1/3 and NDH-11,2, allowing their functions to be dynamically coordinated for efficient oxidation of photosystem I and for photoprotection under variable CO2 and light availability.
AB - In oxygenic photosynthetic organisms, excluding angiosperms, flavodiiron proteins (FDPs) catalyze light-dependent reduction of O2 to H2O. This alleviates electron pressure on the photosynthetic apparatus and protects it from photodamage. In Synechocystis sp. PCC 6803, four FDP isoforms function as hetero-oligomers of Flv1 and Flv3 and/or Flv2 and Flv4. An alternative electron transport pathway mediated by the NAD(P)H dehydrogenase-like complex (NDH-1) also contributes to redox hemostasis and the photoprotection of photosynthesis. Four NDH-1 types have been characterized in cyanobacteria: NDH-11 and NDH-12, which function in respiration; and NDH-13 and NDH-14, which function in CO2 uptake. All four types are involved in cyclic electron transport. Along with single FDP mutants (∆flv1 and Δflv3) and the double NDH-1 mutants (∆d1d2, which is deficient in NDH-11,2 and ∆d3d4, which is deficient in NDH-13,4), we studied triple mutants lacking one of Flv1 or Flv3, and NDH-11,2 or NDH-13,4. We show that the presence of either Flv1/3 or NDH-11,2, but not NDH-13,4, is indispensable for survival during changes in growth conditions from high CO2/moderate light to low CO2/high light. Our results show functional redundancy between FDPs and NDH-11,2 under the studied conditions. We suggest that ferredoxin probably functions as a primary electron donor to both Flv1/3 and NDH-11,2, allowing their functions to be dynamically coordinated for efficient oxidation of photosystem I and for photoprotection under variable CO2 and light availability.
KW - Flavodiiron proteins
KW - Flv
KW - Mehler-like reaction
KW - NDH-1
KW - Synechocystis sp. PCC 6803
KW - alternative electron transfer
KW - cyanobacteria
KW - photoprotection
KW - photosynthesis
UR - http://www.scopus.com/inward/record.url?scp=85087732714&partnerID=8YFLogxK
U2 - 10.1111/tpj.14812
DO - 10.1111/tpj.14812
M3 - Article
SN - 0960-7412
VL - 103
SP - 1460
EP - 1476
JO - Plant Journal
JF - Plant Journal
IS - 4
ER -