Agriculture Reference
In-Depth Information
Fig. 3.3 Cellular organization of sulfate metabolism in
Arabidopsis thaliana
. Enzymes and
transporters are indicated in
purple
characters. Abbreviations of enzymes and transporters:
ATPS
ATP sulfurylase,
APK
APS kinase,
APR
APS reductase,
SiR
sulfite reductase,
OAS-TL
OAS(thiol)lyase,
SAT
serine acetyltransferase,
CGS
cystathionine
ʳ
-synthase,
CBL
cystathionine
ʲ
-lyase,
TS
threonine synthase,
MS
methionine synthase,
SAM S
-adenosylmethionine synthetase,
ʳ
-
ECS ʳ
-glutamylcysteine synthetase,
GSHS
glutathione synthetase,
CLT
thiol transporter,
GST
glutathione-S-transferase,
MRP
multidrug resistance-associated protein,
GGT
ʳ
-glutamyltransferase,
SOT
sulfotransferase,
SULTR
sulfate transporter,
PAPST1
plastidic PAPS
transporter. Abbreviations of metabolites:
APS
adenosine 5
0
-phosphosulfate,
Cys
cysteine,
Cyst
cystathionine,
Hcy
homocysteine,
OPH O
-phosphohomoserine,
Thr
threonine,
Met
methionine,
SAM
S-adenosylmethionine,
SAH
S-adenosylhomocysteine,
-glutamylcysteine,
GSH
glutathione,
GS-X
glutathione conjugate,
Glu
glutamate,
X-CysGyl
cysteinylglycine conjugate,
Ser
serine,
OAS O
-acetylserine,
PAPS
3
0
-phosphoadenosine 5
0
-phosphosulfate,
R-OH
hydroxylated
precursor
ʳ
-
GluCys
ʳ
5
0
-phosphosulfate (PAPS) which serves as a donor of activated sulfate for various
cellular reactions modifying proteins, saccharides or synthesis of secondary metab-
olites including glucosinolates. This process is called sulfation and it is important in
regulating plant growth and development. However, sulfate reduction is a dominant
route for assimilation (Leustek et al.
2000
) and is fulfilled in two steps. In the first
