Post on 01-Apr-2015
ABIOTIC STRESSESABIOTIC STRESSES REDIRECT PROTEIN REDIRECT PROTEIN
SYNTHESISSYNTHESIS
Mikal E. SaltveitMann Laboratory, Department of Vegetable Crops
University of California, Davis
Participants in this research
M.E. Mangrich J.G. Loaiza-Velarde
F.A. Tomás-Barberán M.A. Ritenour
A. RabM. Cantwell
G. Peiser G. López-Gálvez
A A Stimulus ProducesStimulus Produces A Physiological A Physiological
ResponseResponse
Cause and Effect Occur in a Linear Order!
The StimulusWoundingWounding
Produces the Physiological ResponseIncreased PAL ActivityIncreased PAL Activity
Resulting inTissue BrowningTissue Browning
Lettuce leaf tissue
CUT
Signal Signal
CUT
PAL PAL
Lettuce leaf tissue
Wound
Signal
Receptor
DNA
mRNA
Proteinsynthesis
PALPhenylpropanoid metabolism
Receptor
DNA
mRNA
Proteinsynthesis
PAL-IF
Preexistingphenolics
Vacuole
PPO
PODCellularmembranes
PhenolicsPhenolics
Tissuebrowning
Increasedpermeability
0
20
40
60
80
100
Time
Re
lativ
e v
alu
es
Wound signal PAL activity
PAL inactivating factor
Phenolic compounds
HO-
C
OHCOOH
HO
HO
O
O
p-Coumaroylquinic acid
HO-
C
OHCOOH
HO
HO
O
Feruloylquinic acid
CH O-
3
O
OH
COOH
HO
HO
O
4-Caffeoylquinic acidHO-
C
OHCOOH
HO
HO
O
3-Caffeoylquinic acid
HO-
O
3,5-Dicaffeoylquinic acid3,4-Dicaffeoylquinic acid
Quinic acid
OH
HO
COOHHO
HO
NH2
COOHHO-
COOH
HO-
HO-
Phenylalanine Cinnamate p-Coumarate Caffeate Ferulate
HO-
CH O-
3
4,5-Dicaffeoylquinic acid
5-Caffeoylquinic acid(Chlorogenic acid)
COOH COOH COOH
HO-
C
HO-
O
HO-
C
OHCOOH
HO
O
HO-
O
O
HO-
C
HO-
O
HO-
C
OHCOOH
HO
HO
OHO-
O
(Isochlorogenic acid)
HO-
C
OHCOOH
HO
OHO-
O
HO-
CO
HO-
OHO-
C
OHCOOH
HO
OHO-
O
O
HO-
C
HO-
O
COOH
C
C
COOH
O
-
Dicaffeoyltartaric acid
COOH
C
C
COOH
OH--O
HO-
HO-C-
O
Caffeoyltartaric acid
-OH
-OH
C
OCOOH
C
C
COOH
OH--HO
Tartaric acid
O
HO-
HO-
C-O
HO-
C
OHCOOH
HO
HO
O
O
p-Coumaroylquinic acid
HO-
C
OHCOOH
HO
HO
O
Feruloylquinic acid
CH O-
3
O
OH
COOH
HO
HO
O
4-Caffeoylquinic acidHO-
C
OHCOOH
HO
HO
O
3-Caffeoylquinic acid
HO-
O
3,5-Dicaffeoylquinic acid3,4-Dicaffeoylquinic acid
Quinic acid
OH
HO
COOHHO
HO
NH2
COOHHO-
COOH
HO-
HO-
Phenylalanine Cinnamate p-Coumarate Caffeate Ferulate
HO-
CH O-
3
4,5-Dicaffeoylquinic acid
5-Caffeoylquinic acid(Chlorogenic acid)
COOH COOH COOH
HO-
C
HO-
O
HO-
C
OHCOOH
HO
O
HO-
O
O
HO-
C
HO-
O
HO-
C
OHCOOH
HO
HO
OHO-
O
(Isochlorogenic acid)
HO-
C
OHCOOH
HO
OHO-
O
HO-
CO
HO-
OHO-
C
OHCOOH
HO
OHO-
O
O
HO-
C
HO-
O
COOH
C
C
COOH
O
-
Dicaffeoyltartaric acid
COOH
C
C
COOH
OH--O
HO-
HO-C-
O
Caffeoyltartaric acid
-OH
-OH
C
OCOOH
C
C
COOH
OH--HO
Tartaric acid
O
HO-
HO-
C-O
Caf
feo
ylta
rtar
ic a
cid
12
0
Butter leafC
hlor
ogen
ic a
cid
60
50
40
30
20
10
0
LSD 5%
Iceberg Romaine
24 48Hours
6 12 720 24 48Hours
6 12 72
50
40
30
20
10
0Dic
affe
oylta
rtar
ic a
cid
0 24 48Hours
6 12 72
Isoc
hlor
ogen
ic a
cid
24
20
16
12
8
4
0
LSD 5%
LSD 5%
LSD 5%
LSD 5%
LSD 5%
LSD 5%
LSD 5%
LSD 5%
LSD 5%
LSD 5%
LSD 5%
0
Wound, 10 °C
Wound, 5 °C
Ethylene, 10 °C
Ethylene, 5 °C
16
8
4
Iceberg lettuce
Heat-shock
Cut and washed
Held at 5 °C in 95% RH
Periodically assayed for PAL and phenolic compounds
20 40 60
Abs
orba
nce
at 3
20 n
m/g
0.28
0.24
0.20
0.16
0.12
0.08
0.04
0.00
60 sec
30 50 70
Temperature (°C)
How doesheat-shock
reduce subsequent browning in lettuce?
0 200 400 600
Seconds of heat-shock
0.14
0.12
0.10
0.08
0.06
0.04
0.02
0.00100 300 500
PA
L ac
tivity
(µ
mo
l·g
h
)-1-1
45 °C
50 °C
55 °C
Wounded (24 h)
Control (0 h)
120 sec
90 sec
60 sec
~ 6x
Hours
'L' V
alue
0 24 48 72
72
71
70
69
68
67
66
Control
50 °C, 90 sec
55 °C, 60 sec
'a' V
alue
-1
-2
-3
-4
-5
50 °C, 90 sec
55 °C, 60 sec
45 °C, 120 sec
45 °C, 120 sec
Control
Hours0 24 48 72
80
70
60
50
40
30
20
10
0
Control
45 °C, 120 sec
50 °C, 90 sec
55 °C, 60 sec55 °C, 60 sec
Tot
al p
heno
lic c
onte
nt (
µg·
g )-1
HO-
C
OHCOOH
HO
HO
O
O
p-Coumaroylquinic acid
HO-
C
OHCOOH
HO
HO
O
Feruloylquinic acid
CH O-
3
O
OH
COOH
HO
HO
O
4-Caffeoylquinic acidHO-
C
OHCOOH
HO
HO
O
3-Caffeoylquinic acid
HO-
O
3,5-Dicaffeoylquinic acid3,4-Dicaffeoylquinic acid
Quinic acid
OH
HO
COOHHO
HO
NH2
COOHHO-
COOH
HO-
HO-
Phenylalanine Cinnamate p-Coumarate Caffeate Ferulate
HO-
CH O-
3
4,5-Dicaffeoylquinic acid
5-Caffeoylquinic acid(Chlorogenic acid)
COOH COOH COOH
HO-
C
HO-
O
HO-
C
OHCOOH
HO
O
HO-
O
O
HO-
C
HO-
O
HO-
C
OHCOOH
HO
HO
OHO-
O
(Isochlorogenic acid)
HO-
C
OHCOOH
HO
OHO-
O
HO-
CO
HO-
OHO-
C
OHCOOH
HO
OHO-
O
O
HO-
C
HO-
O
COOH
C
C
COOH
O
-
Dicaffeoyltartaric acid
COOH
C
C
COOH
OH--O
HO-
HO-C-
O
Caffeoyltartaric acid
-OH
-OH
C
OCOOH
C
C
COOH
OH--HO
Tartaric acid
O
HO-
HO-
C-O
55 °C, 60 sec
8
6
4
2
0
Control
45 °C, 120 sec 50 °C, 90 sec
55 °C, 60 sec
Hours0 24 48 72
24
20
16
12
8
4
0
Control
45 °C, 120 sec
50 °C, 90 sec55 °C, 60 sec
Caffeoyl tartaric acid
Dicaffeoyl tartaric acid
LSD 5% =
LSD 5% =
Phe
nolic
aci
ds (
µg·
g )
10-1
24
20
16
12
8
4
0
Control 45 °C, 120 sec
50 °C, 90 sec
55 °C, 60 sec
10
8
6
4
2
Control
45 °C, 120 sec
50 °C, 90 sec
55 °C, 60 sec
5-Caffeoyl quinic acid (Chlorogenic acid)
3,5-Dicaffeoyl quinic acid (Isochlorogenic acid)
LSD 5% =
LSD 5% =
Phe
nolic
aci
ds (
µg·
g )
Hours0 24 48 72
-1
Application of a Application of a heat-shock heat-shock after after
woundingwounding
0
0.1
0.2
0.3
0.4
0 5 10 15 20 25 30 35 40
Hours after wounding
PA
L ac
tivity
ControlControl
HS after 8 hHS after 8 h
HS after 1 hHS after 1 h
HS after 24 h
Application of a Application of a heat-shock heat-shock
beforebefore wounding wounding
WoundedWoundedcontrolcontrol
HS -4 h, WHS -4 h, W
W, HS +2 h
W, HS +2 h, W +6 h
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0 5 10 15 20 25 30 35 40
Hours after wounding
PA
L ac
tivity
0.00
0.02
0.04
0.06
0.08
0.10
0.12
-40 -35 -30 -25 -20 -15 -10 -5 0 5
Wounded
Unwoundedcontrol
Heat-shocked
Hours before wounding
PA
L ac
tivity
Wounded
50 °C, 90 sec
Held at 5 °C
It’s not the proteins that are
synthesizedbut the
synthesis of the proteinsthat
protects against browning
Protein synthesis
““NormaNormal”l”
GeneralGeneral
Protein synthesis
““Normal”Normal”
GeneralGeneral Wounding
SignalSignal
PAL
Heat-shock proteins
Heat-shock
Protein synthesis
““Normal”Normal”
GeneralGeneral
“Signal”
Could the linear sequence of metabolic events induced by one stress (e.g., wounding)
be redirected by another abiotic stress
(e.g., heat-shock)?
PALHeat-shock proteins
Heat-shock
Protein synthesis
““Normal”Normal”
Wounding
SignalSignal“Signal”
GeneralGeneral
Heat-shock
Wounding (e.g., of lettuce)
PAL
Phenolics accumulate
Few phenolic compounds present
Very little browningVery little browning
Normal conditions
X
Browning
SignaSignall
No wound No wound signal remainingsignal remaining
Synthesis of HSPs
Recovery from the heat-shock and resumption of normal protein synthesis
It appears that one stress It appears that one stress
((heat shockheat shock) can redirect ) can redirect
and modify the response of and modify the response of
another stress (another stress (woundingwounding))
Chilling Injury is Chilling Injury is Another Stress that is Another Stress that is
Thought to Occur Thought to Occur Through a Linear Through a Linear
Sequence of EventsSequence of Events
Chilling temperaturesChilling temperatures
Membrane phase changeMembrane phase change
Secondary effectsSecondary effects
Primary effectPrimary effect
Primary cause
Increased membrane permeability Influx of calciumDepolymerization of microtubules Reduced photosynthesisProtoplasmic streaming stops Altered enzyme activityToxic metabolites accumulate Altered metabolism
SymptomsSymptomsAccelerated senescence Increased decay Increased water loss Vascular browningAbnormal ripening Tissue discolorationIncreased ethylene production Elevated respiration
Does Their Synthesis Prevent Does Their Synthesis Prevent the Synthesis of an Agent the Synthesis of an Agent Causing Chilling InjuryCausing Chilling Injury??
Do Heat-shock Proteins Protect Do Heat-shock Proteins Protect Against Chilling Injury?Against Chilling Injury?
or
Chilling temperatures
Abnormal metabolism
Accumulated toxins
Chilling injury
Heat-shock
HSPs
Chilling temperatures
Abnormal metabolism
Accumulated toxins
Heat-shock
HSPs
Chilling injuryNo chilling injury
Chilling temperatures
Abnormal metabolism
Accumulated toxins
Chilling injury
Heat-shock
Chilling temperatures
Abnormal metabolism
Accumulated toxins
Chilling injury
Heat-shock
HSPs
No accumulated toxins
No chilling injury
Chilling temperaturesChilling temperatures
Primary effectsPrimary effects
Membranes Microtubules Proteins Pathways
Primary effectsPrimary effects Primary effectsPrimary effects
Secondary effectsSecondary effects Secondary effectsSecondary effectsIncreased membrane permeability Influx of calciumDepolymerization of microtubules Protoplasmic streaming stopsAltered enzyme activity Altered metabolismReduced photosynthesis Toxic metabolites accumulate
Primary cause
Accelerated senescence and decay Increased water lossTissue discoloration Abnormal ripeningIncreased ethylene production Elevated respiration
SymptomsSymptoms
Stress-Induced Stress-Induced Ethylene Production is Ethylene Production is Another Response that Another Response that
Occurs Through a Occurs Through a Linear Sequence of Linear Sequence of
EventsEvents
ETHYLENE SYNTHESIS
Methionine
SAM
ACCACC
C2 H4
ACC Synthase
ACC Oxidase
MACC
Fruit ripeningFlower senescenceAuxin, WoundingChilling, DroughtFlooding
+
AVG, AOA
-Ripening, Ethylene
AnaerobiosisCobalt, > 35 °C
Free radical scavengers
+
-(CO2, O2 )
Hierarchical Response toabiotic stresses
Heat-shock Wounding Non-stressed
??DroughtAnaerobicSaltUV
Participants in this research
M.A. Mangrich F.A. Tomás-BarberánJ.G. Loaiza-Velarde
M.A. RitenourA. Rab
M. Cantwell G. Peiser
G. López-Gálvez