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United States Department of Agriculture

Agricultural Research Service

Title: Restoration of Redox Regulation of the Chloroplast Atp Synthase in Cfq Mutant of Arabidopsis by Genetic Transformation with Wild-Type (-Subnit Gene

item Ortiz, Guadalupe - PLANT BIOLOGY UOFI URBANA
item Ortiz Lopez, Adriana
item Ort, Donald

Submitted to: American Society of Plant Physiologists Meeting
Publication Type: Abstract Only
Publication Acceptance Date: February 5, 1999
Publication Date: N/A

Technical Abstract: The ATP synthase in chloroplast synthesizes ATP from ADP and Pi by coupling the electrochemical potential of protons across the thylakoid membrane with anhydride bond formation. ATP synthase activity is redox regulated during diurnal cycles of light and through dithiol/disulfide exchange between thioredoxin and the ATP synthase (-submit. The cfq (coupling factor quick recovery) mutant of Arabidopsis is unable to reduce the regulatory sulfhydryls of the (-submit. A point mutation in the atpC1 gene coding for the (-subnit of this mutant changed the Glu 244 to a Lys resulting in the loss of the ability for thioredoxin-dependent dithiol transfer as well as loss of a TaI restriction site in the gene. In thyis study, the wild type atpC1 (-subnit gene was transformed into the cfq mutants and overexpressed behind a constitutive promoter. The "A518 relaxation kinetics of the transgenic mutant plants was measured after a preillumination sufficient to fully reduce the regulator sulfhydryls on the wild type ATP syntyhase. By monitoring expression levels of the mutant and wild type atpC1 gene on the basis of the mutation sensitive Taq1 restriction site, we showed that redox regulation of the ATP synthase was restored in cfq mutant plants in proportion to the expression of the wild type gene.

Last Modified: 5/5/2015
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