Abstract Thioredoxins represent ubiquitous small proteins acting as redox regulators of diverse metabolic and developmental processes in almost all organisms. These
proteins contain highly conserved cysteines in their redox-active sites, which enable
the modification of target enzyme conformation and activity by reversible thioldisulfide exchanges. Since their discovery in plants around 40 years ago, the number
of thioredoxin family members as well as the knowledge about their distinct functions
are still increasing and under investigation. Originally, the first plant thioredoxin was
found in chloroplasts, while further analyses demonstrated additional cytosolic,
nuclear, mitochondrial, endomembrane, and non-photosynthetic plastid locations.
This chapter provides an overview on the complexity of the thioredoxin family in
higher plants and discusses its role in integrating metabolism, stress responses,
development, and gene expression. This will help to understand why plants harbor
the most versatile thioredoxin system among all organisms.
Abbreviations
ACHT
Atypical cysteine/histidine-rich thioredoxin
ADP
Adenosine diphosphate
AGPase
ADP-glucose pyrophosphorylase
AMP
Adenosine monophosphate
AOX
Alternative oxidase
APS
AGPase small subunit
ATP
Adenosine triphosphate
ATPase
ATP synthase
CBC
Calvin-Benson cycle
cDNA
Complementary DNA
CDSP
Chloroplastic drought-induced stress protein
CHLM
Mg-protoporphyrin methyl transferase
CxxS
Atypical thioredoxin h with cysteine-x-x-serine active site
Cys
Cysteine
Cyt b 6 f
Cytochrome b 6 f complex
DNA
Deoxyribonucleic acid
ER
Endoplasmic reticulum
FAD
Flavin adenine dinucleotide
FBPase
Fructose 1,6-bisphosphatase
FDX
Ferredoxin
FNR
Ferredoxin NADP
+ reductase
FTR
Ferredoxin thioredoxin reductase
FUM
Fumarase
Gb
Gossypium barbadense
GFP
Green fluorescent protein
GGLC
Glycine-glycine-leucine-cysteine motif
Gly
Glycine
GRX
Glutaredoxin
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I. Thormählen et al.