Journal
EMBO JOURNAL
Volume 19, Issue 19, Pages 5041-5050Publisher
OXFORD UNIV PRESS
DOI: 10.1038/sj.emboj.7593319
Keywords
C-4 plant; cyclic electron flow; ferredoxin isoproteins
Categories
Ask authors/readers for more resources
In the C-4 plant maize (Zea mays L.), two ferredoxin isoproteins, Fd I and Fd II, are expressed specifically in mesophyll and bundle-sheath cells, respectively. cDNAs for these ferredoxins were introduced separately into the cyanobacterium Plectonema boryanum with a disrupted endogenous ferredoxin gene, yielding TM202 and KM2-9 strains expressing Fd I and Fd II. The growth of TM202 was retarded under high light (130 mu mol/m(2)/s), whereas KM2-9 grew at a normal rate but exhibited a nitrogen-deficient phenotype, Measurement of photosynthetic O-2 evolution revealed that the reducing power was not efficiently partitioned into nitrogen assimilation in KM2-9, After starvation of the cells in darkness, the P700 oxidation level under far-red illumination increased significantly in TM202, However, it remained low in KM2-9, indicating an active cyclic electron flow. In accordance with this, the cellular ratio of ATP/ADP increased and that of NADPH/NADP(+) decreased in KM2-9 as compared with TM202. These results demonstrated that the two cell type-specific ferredoxins differentially modulate electron flow around photosystem I.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available