| Photochemical Reflectance Index (PRI)-light response curves |
can reveal |
dynamic xanthophyll cycle activity and photosynthetic downregulation in response to stress |
|
| quantifying differences in the Photochemical Reflectance Index (PRI)-light response in heterogeneous, mixed-species forested landscapes |
was used to evaluate |
within and between species variation in photoprotective responses |
|
| combination of low minimum temperatures and relatively high radiation during late winter to early spring |
most likely induce |
photoprotection processes |
|
| integrated modeling approaches |
have not yet fully incorporated |
PRI-light responses |
|
| photoprotective pigments and cryoprotective compounds |
dissipate excessive light as |
heat |
|
| LHCSR3 |
requires |
calcium (Ca 2+) -sensing protein (CaS, AT5G23060) |
Chlamydomonas reinhardtii |
| Drought group |
has higher NPQ values than |
Water group in low actinic light |
Arabidopsis thaliana |
| low luminal pH |
induces |
NPQ relaxation processes |
Arabidopsis thaliana |
| airborne imaging spectroscopy |
reveals |
variation in photoprotection among individual tree crowns and species |
|
| variation in PRI-light response |
provides useful information on |
photoprotective behaviour related to irradiance patterns |
|
| CET |
protects |
PSI |
Arabidopsis thaliana |
| photoprotective strategies |
encompass |
fluorescence, Photochemical Reflectance Index (PRI), leaf movements, and leaf shedding |
|
| several pairs of species |
suggesting |
interspecific variation in photoprotection |
|
| proxy for illumination |
incorporated into |
multilevel model of PRI-light response |
|
| higher intercepts |
possibly indicating |
less sustained photoprotection |
|
| validation, tests of generality, and expansion of approach |
will hopefully lead to |
improved understanding of relationships between short-term physiological responses and long-term stand dynamics |
|
| DSPR as identified here |
is mostly an expression of |
protection, not damage |
|
| nonphotochemical quenching (NPQ) |
responds to |
fluctuating light |
Arabidopsis thaliana |
| flavonoids |
provides |
UV protection |
|
| intercept of the PRI–PAR albedo relationship |
represented by |
pigment pool sizes |
|
| carotenoids |
are |
photoprotectant pigments |
|
| adaptation to blue light in the green alga Dunaliella salina |
upregulated |
NPQ |
Dunaliella salina |
| lower intercepts and slopes of PRI-light relationship |
indicates |
less facultative photoprotection |
|
| xanthophyll cycle |
dissipates excess absorbed light energy as heat during |
conditions unfavorable for carboxylation |
|
| American basswood (Tilia americana) |
had |
stronger xanthophyll cycle pigment response and steeper declines in photosynthetic LUE with increasing light |
Tilia americana |
| topographically driven PRI–PAR albedo responses |
are expected to |
vary with time of day |
|
| FTSZ1-16 line |
shows significantly higher |
non-photochemical quenching level at 2000 μmol m−2 s−1 |
Nicotiana tabacum |
| Photochemical Reflectance Index (PRI)-light responses of canopy regions |
reflect |
recent light histories associated with canopy position and instantaneous light environments |
|
| violaxanthin deepoxidase (VDE) and (CP22, NPQ4, PSBS, AT1G44575) protein |
constitute |
rapid nonphotochemical quenching mechanisms |
Arabidopsis thaliana |
| energy quenching |
also occurs at |
photosystem I (PSI) level |
|
| kinetics of NPQ/xanthophyll cycle induction and relaxation |
identified in |
dark–light–dark transitions |
Arabidopsis thaliana |
| (CP22, NPQ4, PSBS, AT1G44575) mutant |
lacks |
(CP22, NPQ4, PSBS, AT1G44575) protein |
Arabidopsis thaliana |
| PRI0 |
can distinguish |
long-term pigment pool-size effects (the constitutive response) |
|
| PRI-light responses |
allow |
comprehensive view of photoprotection |
|
| alternative approaches to evaluate results |
could include |
canopy radiative transfer modeling linked to photosynthesis models |
|
| leaves exposed to direct sunlight |
absorb light energy in excess, which is dissipated as heat by |
non-photochemical quenching mechanisms (NPQ) |
|
| interspecific variation in PRI-light responses |
were likely driven by |
constitutive vs facultative effects |
|
| seasonal changes in effects of photoprotection |
can be tracked through |
tracking pigment pools size variation |
|
| HA interference or bypass of Diad or Fuco biosynthesis |
resulting in |
limited photoprotective capability |
Phaeocystis globosa |
| specialized metabolites |
function in |
photosystem protection from excess light |
|
| carotenoids |
play roles in |
photoprotection |
|
| maximal fluorescence yield (Fm') decreased after onset of green light illumination |
correlates with |
induction and relaxation of qT quenching |
Ostreococcus tauri |
| fine pixel resolution |
allows detection of |
diversity in individual and species-level photoprotective responses |
|
| lower PRI values |
suggests |
greater photosynthetic downregulation |
|
| PRI responses |
have been observed in |
intact forest stands using spectrometer mounted on tower |
|
| (OHP2, AT1G34000) protein |
is proposed to have |
photoprotective function |
Arabidopsis thaliana |
| P deficiency treatment |
substantially increases |
energy-dependent quenching component of nonphotochemical quenching |
Hordeum vulgare |
| PRI–PAR albedo responses |
suggest |
species' differences in pigment pool sizes and xanthophyll cycle responses |
|
| airborne method accounting for illumination and sampling at subcanopy level |
provides |
coherent light responses revealing contrasting photoprotection |
|
| multilevel model |
considers |
both facultative and constitutive components of PRI-light response |
|
| within-species variation |
likely reflects |
particular environmental conditions associated with individual's location |
|
| photoprotective compounds in Platycerium bifurcatum sporotrophophylls |
provided protection against |
photoinhibition |
Platycerium bifurcatum |
| NPQ values of drought-treated plants |
higher than |
Water group at low light intensities (≤ 120 μmol photons m −2 s −1 ) |
Arabidopsis thaliana |
| photoprotection |
involves |
fraction of energy dissipated in the form of heat via regulated nonphotochemical quenching (Y NPQ ) |
|
| avoiding photodamage |
requires |
equally rapid regulation |
|
| constitutive (CP22, NPQ4, PSBS, AT1G44575) expression |
enables |
non-photochemical quenching (NPQ) to be switched on within seconds in high light (HL) |
|
| sun-exposed foliage |
had lower intercepts and slopes of |
PRI-light relationship |
|
| ΔPRI |
can distinguish |
short-term xanthophyll cycle activity (the facultative response) |
|
| variation in topographically driven PRI–PAR albedo responses |
illustrates |
value of imaging spectroscopy to characterize shorter term physiological responses |
|
| trees with lower average estimated illumination |
often had |
higher intercepts |
|
| potential applications of PRI–PAR albedo approach |
include |
plant physiology |
|
| some interpretations of PRI-light response |
have not been fully validated at |
this scale |
|
| slower NPQ recovery in Drought group |
indicates |
photoinhibition endured during the measurement |
Arabidopsis thaliana |
| carotenoids |
serve as photoprotective agents that scavenge |
free radicals |
|
| strong negative relationship between PRI and PAR albedo |
is consistent with |
experimental studies showing PRI responds to illumination |
|
| reduction of intrinsic quantum yield of photosynthesis (φ0) |
results in |
reduction of capacity for CO2 assimilation |
|
| enhanced NPQ response |
caused |
higher photosynthetic efficiency and better growth |
Arabidopsis thaliana |
| CET |
protects |
PSII |
Arabidopsis thaliana |
| (CP22, NPQ4, PSBS, AT1G44575) |
is |
expressed constitutively |
|
| photochemical reflectance index (PRI) |
provides measure of |
constitutive pigment levels |
|
| diurnal imagery |
could assemble |
PRI-light response |
|
| soil moisture conditions |
likely influenced |
topographically driven PRI–PAR albedo responses |
|
| many chlorophyll (Chl)-deficient mutants |
are |
light sensitive |
|
| PSII photoprotection enhancement |
involves development of |
non-photochemical quenching (NPQ) capabilities mediated by (CP22, NPQ4, PSBS, AT1G44575) |
|
| excessive illumination |
strongly stimulates biosynthesis of |
anthocyanins |
|
| CYB561A |
plays plausible redox role in modulating |
photoprotective response |
Arabidopsis thaliana |
| facultative and constitutive responses |
represent distinct mechanisms operating over |
different temporal scales |
|
| degree of Photochemical Reflectance Index (PRI) decline with increasing illumination |
indicates |
degree of excess absorbed light |
|
| protection mechanism |
results in |
reduction of trees' photochemical efficiency |
|
| high light |
induces overaccumulation of anthocyanins in |
plants with lower expression of CYB561A gene |
Arabidopsis thaliana |
| adjacent trees of different height and contrasting hydraulic conductance and stomatal conductance |
exhibit different |
Photochemical Reflectance Index (PRI)-light responses |
|
| species differing in intercepts and slopes of PRI–PAR albedo relationship |
were also accompanied by |
substantial differences among individuals of same species |
|
| potential approaches to validation |
could involve |
leaf-level optical and pigment samples |
|
| Drought group |
recovered slower than |
Water group in the dark |
Arabidopsis thaliana |
| Drought group |
has lower NPQ values than |
Water group in saturating light |
Arabidopsis thaliana |
| lower intercepts and slopes of PRI-light relationship |
indicates |
greater constitutive photoprotection |
|
| explicit consideration of PRI responses in context of illumination, species identity, and landscape position |
improves |
physiological and ecological interpretation of photoprotection |
|
| photosynthetic and photoprotective traits |
are |
easily disturbed by many proximal sampling methods |
|
| CET-induced lumen acidification |
contributes to |
NPQ |
Arabidopsis thaliana |
| morning-phased DMGs |
are enriched in |
photoprotection |
Petunia hybrida |
| nonphotochemical quenching |
was severely compromised in |
young leaves of the RNAi plants after 7 d of induction |
Nicotiana tabacum |
| flv4-2 operon |
has a decisive role in |
photoprotection of PSII |
Synechocystis |
| early light-induced proteins (ELIP, ELIP1, AT3G22840) and (ELIP2, AT4G14690) |
are also known as |
Lil1 |
|
| interspecific variation in species' photosynthetic and photoprotective responses |
have been demonstrated in |
common garden studies |
|
| hierarchical framework for distinguishing individual tree crown and species photoprotective responses |
is presented |
in this study |
|
| future work |
should explore |
possible links between early physiological responses and model parameters describing PRI–PAR albedo response |
|
| pigments of the xanthophyll cycle |
have shown |
strong antioxidant properties |
|
| degree of Photochemical Reflectance Index (PRI) decline with increasing illumination |
indicates |
degree of photosynthetic downregulation |
|
| photoprotective pigments and cryoprotective compounds |
downregulate |
plants' photochemical efficiency |
|
| sll0217 - sll0219 (flv4-flv2) operon |
was overexpressed in |
Synechocystis |
Synechocystis |
| lack of psbA2 |
significantly increased |
1O2 production |
Synechocystis |
| all organisms performing oxygenic photosynthesis |
contain |
light-harvesting-like (LIL) proteins |
|
| specific effect of Lute and Zea in providing efficient photoprotection when bound to Lhcs |
accounts for |
(ATCAO, CAO, CH1, AT1G44446) higher sensitivity to high light stress |
|
| binding sites of Zea located inside PSII supercomplexes |
are effective in protecting |
PSII reaction centre |
|
| xanthophylls |
bound at interface between outer antennae and β-carotene-containing subunits may form |
effective safety valve |
|
| flv4-2 operon |
has an important role in |
photoprotection via decreasing the production of 1O2 |
Synechocystis |
| flavonoid accumulation in (ATNTRA, NTR2, NTRA, AT2G17420) (ATNTRB, NTR1, NTRB, AT4G35460) mutant |
protects plants against |
UV-light |
Arabidopsis thaliana |
| flv4-2 operon expression |
and exchange of D1 forms in PSII centers are mutually exclusive photoprotection strategies with |
D1 form exchange in PSII centers upon light stress |
Synechocystis sp. PCC 6803 |
| cyanobacteria and all other oxygenic photosynthetic organisms |
have evolved |
different photoprotection mechanisms |
|
| (AVDE1, NPQ1, AT1G08550) lor1 double mutant |
is |
sensitive to high light |
Chlamydomonas |
| Lil proteins |
function in direct protection of |
PSI and PSII |
|
| (ATCAO, CAO, CH1, AT1G44446) mutants |
showed extreme sensitivity to |
photo-oxidative stress in high light |
|
| (CP22, NPQ4, PSBS, AT1G44575) mutant |
lacks |
qE |
|
| qE |
provides minor contribution to |
photoprotection of PSII photochemistry |
|
| grana membranes from WT and (ATCAO, CAO, CH1, AT1G44446) |
compared for |
photosensitivity |
|
| (54CP, CPSRP54, FFC, SRP54CP, AT5G03940) mutants |
display |
stronger induction of photoprotective mechanisms |
Phaeodactylum tricornutum |
| flv4-2 /OE mutant |
showed large decrease in |
1O2 production |
Synechocystis |
| HliD |
dissipates absorbed energy via direct energy transfer from |
chlorophyll to carotenoid |
|
| (OHP, OHP1, PDE335, AT5G02120) |
could not be formally excluded to be involved directly in |
thermal energy dissipation processes |
Arabidopsis thaliana |
| flv4-2 /OE mutant |
revealed approximately 20% lower amplitude of quenching of maximal fluorescence compared to |
control strains |
Synechocystis |
| (OHP, OHP1, PDE335, AT5G02120) expression |
is increased under |
light stress |
Arabidopsis thaliana |
| plastoquinol oxidase (IM, IM1, PTOX, AT4G22260) |
can act as |
safety valve to dissipate excess absorbed energy |
Arabidopsis thaliana |
| higher PSII activity in flv4-2 /OE mutant |
indicates a decisive role of |
flv4-2 operon |
Synechocystis |
| absence of the OCP photoprotective mechanism |
resulted in |
up-regulation of flv4-2 operon transcripts |
Synechocystis |
| P deficiency treatment |
is 10-fold higher in |
NPQt under steady-state growth light |
Hordeum vulgare |
| functional chloroplasts |
prevent |
phototoxic effects of non-bound photosensitizing pigments and precursor molecules |
|
| small CAB-like proteins (SCPs) |
are found in |
cyanobacterium Synechocystis sp. PCC 6803 |
Synechocystis sp. PCC 6803 |
| (OHP, OHP1, PDE335, AT5G02120) /Lil2 |
encodes |
(OHP, OHP1, PDE335, AT5G02120) protein |
Arabidopsis thaliana |
| (PIFI, AT3G15840) mutant |
exhibits lower capacity for |
non-photochemical quenching |
|
| carotenoid antioxidant capacities in (ATCAO, CAO, CH1, AT1G44446) genotypes |
were not overwhelmed |
high light stress for exposure times shorter than 10 h |
Arabidopsis thaliana |
| (ATCAO, CAO, CH1, AT1G44446) mutants |
were exposed to |
high light (HL) stress |
Arabidopsis thaliana |
| carotenes |
distance from triplet chlorophyll is too large to allow |
direct triplet quenching |
|
| ROS |
causes damage to |
photosynthetic membranes |
|
| anthocyanins |
protect against |
strong light |
|
| flavodiiron proteins (FDPs) |
were recently demonstrated to have |
important role in photoprotection of photosynthetic machinery |
|
| Mehler-like reaction |
differs from genuine plant-type Mehler reaction in that |
there is no production of ROS |
Synechocystis sp. PCC 6803 |
| plant OHPs |
are anticipated to have similar functions to |
cyanobacterial Hlips/Scps |
|
| other fields of plant science |
benefit from |
evaluating spatial or temporal patterns in species photosynthetic and stress responses |
|
| interpretations of PRI-light response |
rest on |
rich history of proximal research linking PRI-light response to photoprotection |
|
| drought conditions |
plants protect themselves from photodamage by increasing |
non-photochemical quenching (NPQ) |
|
| light stress |
induces |
photoprotective mechanism |
|
| zeaxanthin synthesis |
implies |
significant decrease of light harvesting efficiency |
|
| (ATCAO, CAO, CH1, AT1G44446) mutant |
should exhibit increased stress resistance if |
free xanthophyll pool is determinant in photoprotection |
|
| absence of Zea in (AVDE1, NPQ1, AT1G08550) |
does not affect |
photosensitivity of PSI–LHCI |
|
| electron safety valve function of plastid terminal oxidase (IM, IM1, PTOX, AT4G22260) |
would avoid |
photoinhibitory damages at photosystem II (PSII) |
|
| Early-light-induced proteins (ELIPs) |
found to be mostly upregulated genes in |
blueberry buds |
|
| Early-light-induced proteins (ELIPs) |
found to be mostly upregulated genes in |
Rhododendron catawbiense leaves |
Rhododendron catawbiense |
| BBX21-overexpressing plants |
showed protective effect of pigments after exposure to |
high PPFD |
Solanum tuberosum; Arabidopsis thaliana |
| PHYTOCHROME B (HY3, OOP1, PHYB, AT2G18790) overexpression |
increased |
resistance of potato photosynthetic apparatus to UV-B |
Solanum tuberosum |
| (OHP2, AT1G34000) protein |
accumulates in PSI as light intensity increases |
PSI under increasing light intensity |
Arabidopsis thaliana |
| xanthophyll-binding complexes Lhcb |
play a specific role in |
protection of PSII particles from photo-oxidative stress |
|
| xanthophyll-binding complexes Lhcb |
prevent damaging effects of |
singlet oxygen on thylakoid membranes |
|
| zeaxanthin |
has higher photoprotective effect than |
the other xanthophylls |
Arabidopsis thaliana |
| zeaxanthin |
amplitude of effect is strongly enhanced when bound to |
LHC proteins |
|
| lutein |
has been shown to be highly effective in |
direct quenching of 3Chl* |
|
| (ATCAO, CAO, CH1, AT1G44446) plants |
exhibit |
photosensitive phenotype |
|
| downregulation of (ABA1, ATABA1, ATZEP, IBS3, LOS6, NPQ2, ZEP, AT5G67030) |
suggest |
accumulation of zeaxanthin during field cold acclimation (F-CA) |
|
| leaves with higher anthocyanin |
showed relatively less |
chlorophyll degradation and PSII reaction centers closure/degradation |
|
| photoprotection efficiency |
is several times smaller in |
(ATCAO, CAO, CH1, AT1G44446) background with respect to wild-type (WT) background |
|
| zeaxanthin |
provides photoprotection by scavenging |
singlet oxygen (1O2) |
|
| thermal dissipation of 1Chl* (qE and qI) |
is possible mechanism underlying |
decreased production of singlet oxygen by PSII |
|
| Zea bound to V1 site of LHCII |
is not involved in |
direct quenching of chlorophyll triplets |
|
| (PSB29, THF1, AT2G20890) |
provides tolerance to |
high light intensities |
cyanobacteria |
| marked depletion in Lhc subunits |
yields |
higher sensitivity to photo-oxidative stress |
|
| zeaxanthin |
is |
most effective in photoprotection |
|
| protein-bound zeaxanthin |
is more efficient than |
lipid-free zeaxanthin |
|
| oxidizing side inhibition |
is not |
reason for differential ROS yield |
|
| quenching in Nannochloropsis oceanica |
may occur in |
Lhcx1 |
Nannochloropsis oceanica |
| zeaxanthin |
plays key role in protection of |
photosynthetic organisms against excess light |
|
| amplitude of xanthophyll's photoprotective effect |
particularly of zeaxanthin and lutein, strongly depends on |
their binding to Lhc proteins |
|
| light sensitivity |
is induced in absence of |
LHC proteins |
|
| (LUT2, AT5G57030) mutation |
causes smaller increase in rate of lipid peroxidation relative to WT when combined with |
(ATCAO, CAO, CH1, AT1G44446) mutation |
|
| singlet oxygen formation |
leads to |
photobleaching |
|
| Early-light-induced proteins (ELIPs) |
play essential roles in |
photoprotection |
|
| Accumulation of early-light-induced proteins (ELIPs) |
can be triggered by |
various physiological conditions, including light stress and low temperatures |
|
| Accumulation of early-light-induced proteins (ELIPs) |
correlates with |
photosystem II reaction center degradation |
|
| zeaxanthin effect on enhancement of qE |
provides only minor contribution to |
photoprotection |
|
| carotenoids |
are active in preventing |
over-excitation of reaction centers |
|
| (CP22, NPQ4, PSBS, AT1G44575) mutant |
retains ability for |
zeaxanthin synthesis in high light |
|
| additional mechanism |
is needed in order to explain |
efficient protection of thylakoids in wild-type plants compared to (AVDE1, NPQ1, AT1G08550) plants |
|
| energy quenching (qE) |
is fully dependent on |
(CP22, NPQ4, PSBS, AT1G44575) |
|
| (ATCAO, CAO, CH1, AT1G44446) genotypes |
are strongly depleted in |
qE |
|
| carotenoids |
function in |
photoprotection |
|
| cold hard band mechanism |
is found in |
evergreen plants |
|
| ch1npq4 mutant |
are most contrasting with respect to |
photoprotection ability |
|
| npq1lut2 plants |
undergo stronger |
photoinhibition |
|
| zeaxanthin |
induces |
degradation of major LHCII antenna complex |
|
| different xanthophyll species |
are associated with |
different mechanisms |
|
| β-cyclocitral and β-ionone |
accumulate when |
PSII is exposed to a massive excess of excitation energy |
|
| non-photochemical quenching (NPQ) |
is |
protective mechanism |
Solanum lycopersicum |
| protection efficiency against photoinhibition |
strongly depends on |
xanthophyll composition in the presence of Lhc proteins |
|
| (AVDE1, NPQ1, AT1G08550) mutants |
were exposed to |
high light (HL) stress |
Arabidopsis thaliana |
| protein-bound zeaxanthin |
is more efficient in photoprotecting |
PSII (photosystem II) |
|
| plastid terminal oxidase |
reduces |
ROS production |
|
| impairment of ∆pH-dependent mechanisms |
includes |
xanthophyll cycle |
|
| Lhcx4 |
seems not to be involved in |
qE process |
|
| x1KO+x1_D95N_a strain |
showed qE capacity similar to |
wild type |
Phaeodactylum tricornutum |
| Motif 2 |
proved to be highly essential for |
qE establishment |
Phaeodactylum tricornutum |
| early light inducible proteins (ELIPs) |
stabilize the photosynthetic apparatus via |
chlorophyll binding |
|
| xanthophyll cycle |
affects |
adjustment rate of NPQ |
|
| (CP22, NPQ4, PSBS, AT1G44575) mutant lacking qE but retaining zeaxanthin synthesis |
showed that |
protection of thylakoid membrane lipids against photo-oxidation |
|
| lutein |
is |
most effective in photoprotection |
|
| leaf tissues |
attempted to decrease |
absorbance of light energy |
|
| energy quenching (qE) |
is the reason for |
differential sensitivity of (ATCAO, CAO, CH1, AT1G44446) vs WT |
|
| efficiency of Lhc-bound xanthophylls |
is many folds higher and suggests |
specific mechanism of action |
|
| photoprotective advantage of red versus green stems |
was directly proportional to |
difference in anthocyanin content |
|
| slowly reversible down-regulation |
is usual in |
evergreen species |
|
| flashing at highest flash rate of 1 fps |
causes very little |
non-photochemical quenching of chlorophyll excitation energy (NPQ) |
Cucurbita pepo |
| chlororespiration |
impacts |
non-photochemical quenching (NPQ) of chlorophyll fluorescence |
Thalassiosira pseudonana |
| acidification of thylakoid lumen |
seems to be essential for development of |
non-photochemical quenching of Chl a fluorescence (NPQ) |
diatoms |
| weak ΔpH (proton gradient) |
did not cause significant protonation of |
LHC antenna sites |
Thalassiosira pseudonana |
| sensitivity to photo-oxidative stress |
was assessed on |
whole plants |
|
| svr4-1 single mutants |
have enhanced |
non-photochemical quenching (NPQ) capacity |
|
| light |
exceeds capacity of |
photosynthesis |
|
| photoprotective effect |
is specific for |
photosystem II |
|
| altered carotenoid accumulation |
may have direct effects on |
induction and strength of NPQ |
Nicotiana tabacum |
| Substantial upregulation of early-light-induced proteins (ELIPs) |
suggests |
photoprotection and/or photoinhibition was more obvious during field cold acclimation |
|
| binding of zeaxanthin (Zea) to light-harvesting complexes (Lhc) |
enhances efficiency to quench |
singlet oxygen (1O2) |
|
| zeaxanthin |
is effective in photoprotection of |
lutein-less plants |
|
| substantial decrease in qP |
indicates |
stronger photoprotection |
|
| TL amplitude at 135°C at different time points |
was measured during |
exposure of plants to high light stress |
Arabidopsis thaliana |
| parameter b |
can be used as |
photoprotection index |
|
| zeaxanthin |
appears to be the most effective xanthophyll based on |
rate of lipid peroxidation |
|
| accumulation of Zea in non-ch1 background |
slows down by three-fold |
1O2-dependent chlorophyll bleaching rate |
|
| β-carotene |
plays a role in PSII photoprotection by quenching |
singlet oxygen |
|
| Viola |
is exchanged with |
zeaxanthin |
|
| xanthophylls |
protect |
thylakoid lipids |
|
| zeaxanthin |
is absent in |
low light conditions |
|
| zeaxanthin |
induces |
PsbS-independent chlorophyll triplet excited state quenching (qI) |
|
| zeaxanthin (Zea)–light-harvesting complex (Lhcb) complexes |
likely involved in |
protective action distinct from qE and singlet oxygen scavenging |
|
| PSII core |
is more sensitive to photobleaching due to |
strongly increased rate of singlet oxygen production upon illumination |
|
| discrepancy between peroxy-lipid accumulation and bound Zea scavenging contribution |
suggests |
specific photoprotective mechanism distinct from direct scavenging of singlet oxygen |
|
| virus-induced gene silencing plants |
display increased resistance of photosynthesis to |
chilling and high-light stress |
Nicotiana tabacum |
| (SAPX, AT4G08390) (AtPGR5, PGR5, AT2G05620) and (TAPX, AT1G77490) double mutants |
exhibited a phenotype comparable to |
(AtPGR5, PGR5, AT2G05620) single mutants |
|
| green algae |
carry out qE by |
LHCSR proteins |
|
| conformational changes |
result in |
energy dissipation within the antennae of PSII |
|
| qE capacities provided by introduction of Lhcx1 protein lacking aspartate D95 |
closely resemble |
qE levels obtained by introducing wild type Lhcx1 gene |
Phaeodactylum tricornutum |
| direct activation of Lhcx proteins |
could provoke |
at least some of the qE response |
|
| Lhcx1/2, Lhcx4, and Lhcx6 of Thalassiosira pseudonana |
fulfill similar role as |
Lhcx1, Lhcx2, and Lhcx3 in Phaeodactylum tricornutum |
Thalassiosira pseudonana; Phaeodactylum tricornutum |
| stressed plants |
were dissipating energy by |
external heat emission |
|
| photosynthetic organisms |
have evolved mechanisms to dissipate |
excess absorbed light energy |
|
| zeaxanthin-activated state of LHCII |
could represent |
qI component of non-photochemical quenching (NPQ) |
|
| cooperative increase in photoresistance of multiple xanthophyll species |
has been reported in |
isolated Lhc proteins and in vivo with Arabidopsis mutants |
Arabidopsis thaliana |
| photoinhibitory pressure caused by lack of (FTSH2, VAR2, AT2G30950) |
is ameliorated early in chloroplast development by |
enhanced non-photochemical quenching (NPQ) capacity |
|
| photoprotective capacity |
strongly depends on |
leaf age |
|
| leaf tissues |
attempted to decrease light absorbance by reducing |
light-harvesting complexes |
|
| Extents of upregulation of early-light-induced proteins (ELIPs) |
more than in |
Experiments II and III |
|
| x1KO strain |
does not have |
qE capacity |
Phaeodactylum tricornutum |
| anthocyanins |
provide protection against |
UV radiation |
|
| β-cyclocitral (β-CC) |
is involved in |
high light stress response |
|
| zeaxanthin |
binds to |
site L2 of antenna proteins |
|
| zeaxanthin distribution |
is of particular interest for |
photoprotection |
|
| zeaxanthin |
provides photoprotection independently from |
qE (fast component of non-photochemical quenching) |
|
| functional LHCs |
are absent in |
(ATCAO, CAO, CH1, AT1G44446) genetic background |
|
| nonphotochemical energy quenching (NPQ) |
reduces |
ROS production |
|
| wild-type plants and (SAPX, AT4G08390) (TAPX, AT1G77490) |
did not show marked damage symptoms (e.g. photobleaching) during |
high-light stress treatment |
|
| light induced non-photochemical fluorescence quenching (NPQ) |
is characterized by |
reduction of cellular Chl a autofluorescence |
|
| ΔpH |
triggers |
qE by protonating LhcSR |
Chlamydomonas reinhardtii |
| (CP22, NPQ4, PSBS, AT1G44575) |
switches |
outer antennae in dissipative state |
|
| plastid structure development |
accommodates |
photoprotective pigments |
|
| blue-light photoreceptors |
activate |
chloroplast avoidance movements |
|
| strategy to respond to excess light |
targets damage preferentially to |
photosystem II (PSII) |
|
| P deficiency treatment |
increases nonphotochemical quenching sharply immediately after onset of illumination and maintains higher levels throughout illumination compared to |
control and P-resupply treatments |
Hordeum vulgare |
| (AtPGR5, PGR5, AT2G05620) (CRR2, AT3G46790) and (SAPX, AT4G08390) (TAPX, AT1G77490) mutants |
exhibited low NPQ induction upon exposure to |
actinic light compared with wild-type plants |
|
| Fv/Fm value and visible phenotype in (CP22, NPQ4, PSBS, AT1G44575) and (SAPX, AT4G08390) (TAPX, AT1G77490) |
showed no difference between |
(CP22, NPQ4, PSBS, AT1G44575) and (SAPX, AT4G08390) (TAPX, AT1G77490) mutants |
|
| mosses |
simultaneously rely on |
three-helix protein LhcSR |
|
| Dt/Chl a quenching pair |
could lead to |
substantial amount of quenching observed in diatoms |
|
| zeaxanthin (Zea) acting as quencher of exogenous singlet oxygen (1O2) |
shows much weaker differential effect in |
(AVDE1, NPQ1, AT1G08550) mutant vs WT comparison |
|
| lack of light-harvesting complexes in (ATCAO, CAO, CH1, AT1G44446) mutants |
yielded |
strong increase in damage |
|
| lutein |
promotes |
triplet chlorophyll quenching |
|
| carotenoids |
protect the cells from |
photooxidative damage |
|
| attenuation of PAR, especially green/yellow light, by anthocyanins |
is primarily attributable to |
differences in PSII quantum yields between red and green stems |
Cornus stolonifera |
| zeaxanthin |
up-regulates |
several protection mechanisms of plants |
|
| binding of zeaxanthin to V1 site of LHCII |
is proposed to promote |
transition of LHCII to zeaxanthin-activated state |
|
| purified Photosystem II (PSII) complexes |
retaining or lacking |
LHC subunits |
|
| light-harvesting complexes |
might form |
protective shield surrounding PSII reaction center |
|
| no significant difference in low freezing tolerance (LFT) after 56-day cold acclimation (CA) in Experiments II and III |
suggests |
role of anthocyanin was more related to photoprotection than to increasing freezing tolerance (FT) |
|
| x1KO+x1_D95N strains |
exhibited |
pronounced qE capacity |
Phaeodactylum tricornutum |
| aspartic acid in position 95 |
is not needed to provide |
qE by Lhcx1 |
Phaeodactylum tricornutum |
| proanthocyanidin |
protects plants from |
ultraviolet light |
|
| light-harvesting complexes (LHCs) |
switch from light-harvesting mode to |
energy-dissipation mode |
|
| energy-dependent fluorescence quenching (qE) |
regulates |
dissipation of energy absorbed in excess within the antenna of PSII |
|
| upregulation of Lhcx1/2, Lhcx4, and Lhcx6 under high light stress |
correlates with |
higher qE capacity |
Thalassiosira pseudonana |
| carotenoids |
participate in |
photoprotection |
|
| qE |
protects |
PSII |
Arabidopsis thaliana |
| constitutively high zeaxanthin levels in aba 1-6 mutant |
ensure |
rapid, sensitive, and reversible response to changes in thylakoid lumen pH |
Arabidopsis thaliana |
| Zn+ light-adapted leaves |
show increase in |
non-photochemical quenching parameter (NPQ) |
Phragmites australis |
| epidermal localization of anthocyanins |
allows spring sun-exposed leaves to function as |
illustrations of anthocyanins functioning as a screen |
Acer platanoides; Cornus avellana |
| anthocyanins in Acer platanoides leaves |
reduce light absorption by leaf photosynthetic apparatus between 400 nm and 600 nm by |
more than two times |
Acer platanoides |
| chloroplast relocation |
was expected to occur more slowly than |
fast mesophyll conductance (gm) reduction under blue light |
Nicotiana tabacum; Platanus orientalis |
| chloroplasts |
move away from |
blue light |
|
| x1KO strains |
do not have |
qE capacity when cultivated at low light |
Phaeodactylum tricornutum |
| mutation of asparagine residue in Lhcx4 to aspartic acid (x4_N98D) |
did not establish |
qE functional form of Lhcx4 |
Phaeodactylum tricornutum |
| S. robusta |
responds to high irradiances by |
expression of photoprotective LHCX genes |
Seminavis robusta |
| energy dissipation in light-harvesting complexes (LHCs) |
was thought to be independent of |
photoreceptor-signaling |
|
| zeaxanthin synthesis |
must be temporally limited |
zeaxanthin synthesis |
|
| (54CP, CPSRP54, FFC, SRP54CP, AT5G03940) mutants |
have |
20–30% higher Non-Photochemical Quenching capacity than WT |
Phaeodactylum tricornutum |
| lack of chloroplast APXs |
partially alleviates |
failure of NPQ induction in (AtPGR5, PGR5, AT2G05620) |
|
| partial recovery of the de-epoxidation state of xanthophylls |
indicates that |
xanthophyll cycle activity was partially recovered in (SAPX, AT4G08390) (TAPX, AT1G77490) (AtPGR5, PGR5, AT2G05620) |
|
| mosses |
contain and utilize |
(CP22, NPQ4, PSBS, AT1G44575) |
|
| ΔpH |
is only necessary for regulating |
xanthophyll cycle |
|
| xanthophyll cycle |
is hardly involved in |
qE |
Chlamydomonas reinhardtii |
| centric diatom Cyclotella meneghiniana |
has |
qE component that responds directly to ΔpH |
Cyclotella meneghiniana |
| association of monomeric (CP22, NPQ4, PSBS, AT1G44575) with classical light harvesting proteins |
leads to |
dissipative state |
|
| photosynthetic control |
protects |
PSI |
Arabidopsis thaliana |
| formation of zeaxanthin, together with the function of (CP22, NPQ4, PSBS, AT1G44575) protein |
is responsible for |
thermal dissipation of excess excitation energy |
|
| this tryptophan |
might be involved in |
interaction with xanthophyll cycle pigments |
Phaeodactylum tricornutum |
| actual quenching process |
possibly occurs in |
proteins other than Lhcx |
Phaeodactylum tricornutum |
| photoreceptors activated by blue and UV-B light |
control |
energy dissipation |
|
| (SPPA, SPPA1, AT1G73990) |
does not have a direct positive role in |
photoprotection under acute stress |
Arabidopsis thaliana |
| red leaves of Cistus creticus |
show less evident capacity for increase in |
total carotenoids and xanthophyll cycle components |
Cistus creticus |
| chloroplast movement in the avoidance position |
reduces |
surface of chloroplasts exposed to intercellular airspaces |
|
| partial recovery of NPQ induction in (SAPX, AT4G08390) (TAPX, AT1G77490) (AtPGR5, PGR5, AT2G05620) |
might suggest that |
the additional lack of chloroplast APXs partially alleviated the failure of ΔpH formation in (AtPGR5, PGR5, AT2G05620) |
|
| (SAPX, AT4G08390) (TAPX, AT1G77490) (CRR2, AT3G46790) triple mutant |
did not show |
an high-light-sensitive phenotype |
|
| energy-dependent fluorescence quenching (qE) |
is |
fastest NPQ subtype |
|
| three conserved, lumenally exposed acidic amino acid residues and C-terminal hydrophilic tail containing acidic amino acids in LhcSR |
are involved in |
direct response to lumen acidification |
Chlamydomonas reinhardtii |
| Motif 1 |
may be important, but not the only domain to fulfill |
some function in qE establishment |
Phaeodactylum tricornutum |
| Lhcx1/2, Lhcx4, and Lhcx6 of Thalassiosira pseudonana |
are upregulated under |
high light stress |
Thalassiosira pseudonana |
| Dt molecule |
putatively binds at |
motif 2 |
Phaeodactylum tricornutum |
| high light |
induces |
monomerization of (CP22, NPQ4, PSBS, AT1G44575) |
|
| modulation of interaction with themselves or Lhcf proteins via motif |
eventually results in |
switching on/off qE by disconnecting or reconnecting peripheral antenna to PSII |
Phaeodactylum tricornutum |
| high light (HL) grown plants |
show increased |
qE capacity |
Arabidopsis thaliana |
| (SAPX, AT4G08390) (TAPX, AT1G77490) (AtPGR5, PGR5, AT2G05620) triple mutant |
partially recovered |
failure of induction of non-photochemical quenching (NPQ) |
Arabidopsis thaliana |
| low NPQ levels in x1KO strain |
are not related to |
qE |
Phaeodactylum tricornutum |
| Chl c |
would make involvement in |
direct quenching mechanism |
Phaeodactylum tricornutum |
| LHCX2 |
is able to provide |
qE (non-photochemical quenching) |
Phaeodactylum tricornutum |
| LHCX1 |
is able to mediate qE independently of |
presence of two lumenal-exposed acidic amino acids |
Phaeodactylum tricornutum |
| motif 2 of Lhcx1/2/3 proteins |
is highly essential for |
Lhcx proteins to provide qE |
Phaeodactylum tricornutum |
| ΔpH |
is not for triggering |
qE directly |
|
| increased carotenoid pigment production |
provides |
photo-damage protection |
Chlamydomonas reinhardtii |
| marked decrease in Fv/Fm in npq mutants |
is apparently supported by |
importance of xanthophyll cycle for PSII protection |
|
| Lhcx proteins |
depending on presence of Dd or Dt can modulate |
interaction with themselves or Lhcf proteins via motif |
Phaeodactylum tricornutum |
| (ABC1K1, ACDO1, AtACDO1, PGR6, AT4G31390) (ABC1K3, AT1G79600) double-mutant under moderate light stress |
shows striking accumulation of |
zeaxanthin, β-carotene, lutein and violaxanthin |
Arabidopsis thaliana |
| regulated non-photochemical quenching |
increases |
fraction of absorbed light energy at photosystem II (PSII) dissipated as heat |
|
| photosynthetic organisms |
need to regulate |
light harvesting |
|
| specific photoprotective mechanism arising from Zea–Lhcb interactions |
contributes to decreasing |
1O2 yield in high light |
|
| LHCSR |
dissipates |
harmful excess light energy |
Chlamydomonas reinhardtii |
| phenylpropanoid pathway |
plays an important role in protection of pollen against |
UV radiation |
|
| state transition |
reduces |
ROS production |
|
| photoprotective strategies in evergreens |
enhance |
thermal dissipation |
|
| energy absorbed by a leaf |
is managed through |
thermal processes |
|
| xanthophyll cycle |
is considered to play key roles in |
protecting plants against potentially damaging effects of excess light |
|
| pre-illumination time |
increases |
relative rate of NPQ formation |
Brassica campestris; Oryza sativa |
| chloroplast APXs |
partially complement defects in |
PGR5-dependent photoprotection |
|
| qE (energy-dependent quenching) |
is |
∆pH-dependent mechanism |
|
| LhcSR in Chlamydomonas reinhardtii |
contains |
C-terminal hydrophilic tail containing a couple of acidic amino acids |
Chlamydomonas reinhardtii |
| Chl/carotenoid interaction |
is proposed to be involved in |
actual quenching process |
Chlamydomonas reinhardtii; Nannochloropsis oceanica |
| Phaeodactylum tricornutum mutants with truncated peripheral Lhcf antenna |
possess |
fully operational xanthophyll cycle |
Phaeodactylum tricornutum |
| tryptophan residue in peptide motif |
is mandatory for |
qE induction |
Phaeodactylum tricornutum |
| increased relative abundance of VDE |
accelerates |
zeaxanthin synthesis |
Arabidopsis thaliana |
| increased relative abundance of (CP22, NPQ4, PSBS, AT1G44575) |
has been shown to adjust |
ΔpH sensitivity of qE |
Arabidopsis thaliana |
| decrease in lamina size |
helps to avoid |
light-induced damage to photosystems |
|
| extent of qE |
varies enormously between |
different diatom species |
|
| x1KO+x1_motif-1_b strain |
did not recover |
qE capacity |
Phaeodactylum tricornutum |
| Lhcx4 |
is not involved in |
qE process |
Phaeodactylum tricornutum |
| carotenoids |
are central for |
photoprotection |
|
| regulation of energy partitioning in PSII complexes |
could minimize |
damaging potential |
Wedelia trilobata |
| Lobelia erinus |
although quantum efficiencies were depressed less in red than in green stems when subjected to saturating light, the measured benefit was |
smaller than might be predicted based on its anthocyanin content |
Lobelia erinus |
| violaxanthin |
is involved in |
protection of photosynthesis against salinity stress and excess light |
|
| cabbage leaves |
have higher |
NPQ values |
Brassica campestris |
| unidentified photo-protective mechanisms independent of the D1 repair cycle |
exist in |
Chlamydomonas raudensis Ettl. UWO 241 |
Chlamydomonas raudensis |
| (SAPX, AT4G08390) and (TAPX, AT1G77490) |
play a crucial role in |
photoprotection in the pgr5-background |
|
| lack of APXs |
did not restore NPQ in |
the (AtPGR5, PGR5, AT2G05620) (CRR2, AT3G46790) background |
|
| partial recovery of NPQ induction in (SAPX, AT4G08390) (TAPX, AT1G77490) (AtPGR5, PGR5, AT2G05620) |
is consistent with |
partial recovery of the de-epoxidation state of xanthophylls |
|
| lack of conserved acidic amino acid residue in Lhcx4 |
might be responsible for |
absent ability of Lhcx4 to mediate qE |
Phaeodactylum tricornutum |
| direct protonation |
triggers |
qE component |
|
| crystal structure of Lhcx protein |
is required to unravel |
further mechanistic details of Lhcx-mediated qE mechanism |
Phaeodactylum tricornutum |
| both photosynthetic control and qE mechanisms |
are induced by |
build-up of ΔpH |
Arabidopsis thaliana |
| red Cornus stolonifera leaves |
recover rapidly to maximum value when returned to |
darkness |
Cornus stolonifera |
| dissipation of excess energy |
limits formation of |
reactive oxygen species (ROS) |
|
| zeaxanthin |
is |
of particular interest for photoprotection |
|
| activation of qI |
is associated with |
large xanthophyll cycle pool |
|
| mutants lacking chlorophyll b |
showed |
marked depletion in Lhc subunits |
|
| reduced content in LHCI–Zea complexes |
may contribute to |
photosensitivity of (ATCAO, CAO, CH1, AT1G44446) genotypes |
|
| (CP22, NPQ4, PSBS, AT1G44575) mutation in WT and (ATCAO, CAO, CH1, AT1G44446) background |
results in |
rather small increase in photosensitivity (1.5-fold) |
|
| zeaxanthin substituting violaxanthin into site V1 of LHCII |
avoids formation of |
Zea aggregates through docking to LHC proteins |
|
| npq1lut2 plants |
undergo stronger |
lipid oxidation |
|
| lutein–zeaxanthin combination |
photoprotection is magnified by binding to |
LHCs |
|
| photoprotective strategies in evergreens |
permanently decrease |
light absorbance |
|
| Group III Fcps |
are proposed to function in |
light protection |
|
| xanthophylls (violaxanthin, antheraxanthin, and zeaxanthin) |
are supposed to play important roles in |
photoprotection of plants against excess light stress |
|
| NPQ formed and relaxation rates |
are obviously different between |
cabbage and rice |
Brassica campestris; Oryza sativa |
| (CP22, NPQ4, PSBS, AT1G44575) genes in green algae |
have exact role that is still unclear |
exact role in photoprotection |
|
| Chl a /zeaxanthin interactions |
are involved in |
qE process |
Nannochloropsis oceanica |
| conversion of Dd to Dt |
may have |
fundamental consequences for oligomerization states and/or interaction with other Lhc proteins |
Phaeodactylum tricornutum |
| dihydroactinidiolide (dhA) |
is involved in |
photoacclimation |
|
| x1KO+x1_motif-1_c strain |
recovered |
some qE capacity |
Phaeodactylum tricornutum |
| advantages of anthocyanins |
were most evident for west-facing stems only in |
the morning |
|
| Lobelia erinus |
proved to be |
the exception in the study |
Lobelia erinus |
| NaCl stress |
induces changes in |
non-photochemical quenching (NPQ) |
Oryza sativa; Brassica campestris |
| exogenous ABA application |
alleviated excessive light effects in |
NaCl-treated rice plants |
Oryza sativa |
| electrons exiting the PSII core complex |
can otherwise be dissipated via |
glutathione–ascorbate cycle |
|
| high-light-inducible proteins (HLIPs) |
are induced by |
high light stress |
|
| CAB/ (ELIP, ELIP1, AT3G22840) /HLIP superfamily members |
function in |
photoprotection |
|
| GLUTATHIONE PEROXIDASE HOMOLOGOUS (GPXH) gene |
is highly expressed in |
cells exposed to singlet oxygen generation in the chloroplasts |
Chlamydomonas reinhardtii |
| (CRR2, AT3G46790) mutant |
did not show |
an high-light-sensitive phenotype |
|
| green algae |
have involvement of xanthophyll cycle in rapid photoprotection that is largely |
species dependent |
|
| PSII supercomplex disassembly |
facilitates |
PSII repair or NPQ |
Arabidopsis thaliana |
| larger leaf lamina and overall canopy size |
would make more difficult |
maintenance and protection of photosystems |
|
| acidification of the chloroplast stroma |
may interfere with |
xanthophyll cycle for non-photochemical energy dissipation |
|
| NPQ mechanism in diatoms |
shares common features with |
NPQ mechanism of vascular plants |
diatoms; vascular plants |
| green and anthocyanic leaves in Galax urceolata |
show similar differences in photoinhibition as |
green and anthocyanic leaves in Cornus stolonifera |
Galax urceolata |
| chlororespiratory electron flow |
is important in light of increase in |
NPQ-sensitivity of diatoxanthin (Dtx) during reoxygenation |
Thalassiosira pseudonana |
| flavonoids |
provide protection from |
ultraviolet (UV) light |
|
| photoprotection and recovery processes |
use |
reducing power |
|
| addition of exogenous ABA |
causes rise in level of |
non-photochemical quenching (NPQ) |
Oryza sativa; Brassica campestris |
| anthocyanin levels per chlorophyll unit |
showed no differences between |
reproductive (R) and nonreproductive (NR) shoots |
|
| anthocyanic periderm removal |
retains small differences in |
Ф PSII of underlying chlorenchyma |
Cornus stolonifera |
| anthocyanins in senescing leaves of Cornus stolonifera |
show reduced photoinhibition compared to |
acyanic senescing leaves of Cornus stolonifera |
Cornus stolonifera |
| woody stems |
may have reduced capacities to |
dissipate excess light energy as heat |
|
| close correspondence in light curves for photochemical yield in red and green stems |
indicates |
anthocyanins probably assist photoprotection indirectly by abating incident quantum fluxes |
|
| state transition-dependent quenching (qT) |
is absent in |
diatoms |
diatoms |
| Fcps in diatoms |
function in |
photoprotection |
|
| up-regulation of all photoprotection mechanisms in red stems |
would reduce |
excitation pressure on the chloroplasts |
|
| differences in spectral output between lamps and sunlight |
can lead to |
underestimation of natural effects of anthocyanins on green light-screening |
|
| non-photochemical quenching (NPQ) |
is not fully active at |
low irradiance |
|
| re-introduction of oxygen |
increased significantly |
non-photochemical quenching of Chl a fluorescence (NPQ) |
Thalassiosira pseudonana |
| anthocyanin biosynthesis in stems |
in turn protects |
cortical chloroplasts from adverse effects of prolonged exposures to high light |
|
| lack of chloroplast APXs alone |
did not affect |
induction of non-photochemical quenching |
|
| LhcSR acidic amino acids |
sense |
ΔpH |
Chlamydomonas reinhardtii |
| photoinactivated PSII quenching |
is caused by |
thermal dissipation of excitation energy by photodamaged PSII complexes |
|
| complex and multi-pronged strategy for photoprotection and recovery |
has |
mutual support from the several processes involved |
|
| chloroplast avoidance response |
would not protect |
top layer of chloroplasts |
Cucurbita pepo |
| chloroplast avoidance response |
affects mostly transmission of |
blue light |
Cucurbita pepo |
| dark incubation in presence of uncoupler |
prevented |
non-photochemical quenching (NPQ) |
Phaeodactylum tricornutum |
| lower ratios of VAZ/total carotenoids in red leaves during winter |
could be interpreted as |
inherent inability of red phenotype to up-regulate xanthophyll pool size |
Cistus creticus |
| photoprotective hypothesis |
is assessed across |
five unrelated species which show variation in stem colour |
|
| anthocyanins |
increased in |
internodes exposed to full sunlight |
|
| most leaves |
have |
panoply of mechanisms for eliminating supernumerary quanta |
|
| non-net carboxylative mechanisms (NC) |
is the main photoprotective mechanism at |
low irradiance levels |
|
| inorganic carbon accumulation in diatom cells |
strongly reduces |
photoinhibitory quenching of chlorophyll fluorescence (qI) |
diatoms |
| flavonoids |
afford |
UV protection |
|
| high temperature |
did not enhance |
de-epoxidation state (DES) of xanthophyll cycle in Wedelia chinensis |
Wedelia chinensis |
| photosynthetic apparatus |
transitions from light harvesting to photoprotective state |
non-photochemical quenching (NPQ) |
diatoms |
| glycolate metabolism pathway |
is thought to serve a role in |
dissipation of energy under conditions of high light and temperature |
Arabidopsis thaliana |
| young leaves of Quercus coccifera |
showed no evidence for |
actual photoprotection |
Quercus coccifera |
| senescing leaves of many woody species |
showed no evidence for |
actual photoprotection |
|
| total carotenoids/Chl ratio |
was similar in |
two leaf types |
Cistus creticus |
| chloroplast movement to avoid photodamage |
might cause |
reduction of mesophyll conductance (gm) |
Nicotiana tabacum; Platanus orientalis |
| excessive light and elevated temperatures |
exacerbate |
water stress effects on light energy dissipation and xanthophyll cycling |
Nicotiana tabacum |
| (54CP, CPSRP54, FFC, SRP54CP, AT5G03940) KO mutants |
display stronger induction of |
photoprotective mechanisms |
Phaeodactylum tricornutum |
| accumulation of non-functional PSII |
is connected to |
downregulation of the activity and amount of zeaxanthin epoxidase (ABA1, ATABA1, ATZEP, IBS3, LOS6, NPQ2, ZEP, AT5G67030) |
Arabidopsis thaliana |
| (AtPGR5, PGR5, AT2G05620) mutant |
could not sufficiently induce |
non-photochemical quenching (NPQ) |
|
| both ΔpH-dependent regulatory mechanisms, the xanthophyll cycle and photosynthetic control |
are simultaneously compromised in |
(AtPGR5, PGR5, AT2G05620) mutant |
|
| (CP22, NPQ4, PSBS, AT1G44575) |
senses and triggers |
energy-dependent fluorescence quenching (qE) |
|
| x1KO+x1_W133M lines |
recovered |
some qE capacity |
Phaeodactylum tricornutum |
| anthocyanin |
protects plants from |
ultraviolet light |
|
| cauline anthocyanins |
attenuate |
photosynthetically active radiation (PAR) |
Cornus stolonifera |
| photoprotective quenching |
is realized by |
xanthophyll cycle |
|
| carotenoids (Caro) |
could act as |
photoprotectant |
Populus cathayana |
| far-red (FR) light illumination |
increases sensitivity of |
NPQ to diatoxanthin (Dtx) |
Thalassiosira pseudonana |
| illumination with far-red (FR) light |
increased significantly |
non-photochemical quenching of Chl a fluorescence (NPQ) |
Thalassiosira pseudonana |
| Lhcx1, Lhcx2, and Lhcx3 |
are involved in |
qE process |
Phaeodactylum tricornutum |
| S. robusta |
responds to high irradiances by |
downwards migration into the sediment |
Seminavis robusta |
| sub-optimal trans-thylakoid ΔpH |
may cause reduced activity of |
non-photochemical quenching (NPQ) |
|
| photon exposure of ∼5 mol photons m −2 |
leads to gross loss of |
about half of the active PSII |
|
| exogenous ABA |
influences |
activity of energy dissipation process (NPQ) |
Brassica campestris; Oryza sativa |
| full complement of energy dissipation methods |
include |
photorespiration, radiative energy dissipation via zeaxanthin, futile xanthophyll cycle, and D1-protein turnover |
|
| photoprotective advantage |
correlates linearly and interspecifically with |
anthocyanin concentration differences among red and green internodes |
multiple species |
| thermal dissipation of excess excitation energy |
is |
important photoprotective mechanism |
|
| major protective mechanism against photodamage |
may be different for |
two plant species (Wedelia chinensis and Wedelia trilobata) |
Wedelia chinensis; Wedelia trilobata |
| Φf,D in Wedelia trilobata |
decreased slightly |
high temperature |
Wedelia trilobata |
| chloroplast positioning at edges of mesophyll cells |
maximizes |
self-shading |
|
| abaxial anthocyanins |
have been implicated to function in |
photoprotection |
|
| (ELIP, ELIP1, AT3G22840) levels in both mutant lines |
remained higher relative to |
wild-type plants during early recovery from HL treatment |
Arabidopsis thaliana |
| acidification of the lumen |
is needed for development of |
non-photochemical quenching (NPQ) |
Phaeodactylum tricornutum |
| increased light harvesting |
is at the expense of |
photoprotection |
Chlamydomonas raudensis |
| carotenoids |
function in photoprotection by |
protecting photosynthetic systems against reactive oxygen species (ROS) |
|
| anthocyanins in leaves |
may provide |
photoprotection of chloroplasts |
|
| increased fraction of ΦNPQ |
is partly associated with |
increased trend towards xanthophyll cycle pigment pool (V+A+Z) |
Wedelia chinensis; Wedelia trilobata |
| increases in Φ NF |
arise at the expense of |
Φ REG |
Miscanthus sinensis; Miscanthus sacchariflorus; Saccharum |
| photoprotection capacity in R shoots |
is higher in |
R shoots relative to NR shoots in females |
Pistacia lentiscus |
| flavonols |
serve as |
UV protectants during berry ripening |
Vitis vinifera |
| anthocyanin accumulation |
has |
role in photoprotection |
|
| higher non-photochemical quenching (NPQ) associated with lower chlorophyll/carotenoid ratio resulting from increase in carotenoid content in 5P2 |
probably indicates that ABP9 could function in |
protecting photosynthesis apparatus through improving photoprotective thermal dissipation and enhancing antioxidative ability |
Arabidopsis thaliana |
| (ELIP, ELIP1, AT3G22840) over-expression |
may lead to |
increased photoprotection |
Arabidopsis thaliana |
| anthocyanins |
have putative roles in |
photoprotection |
|
| carotenoids in green tissues |
function as |
photo-oxidation protectants |
|
| critical role for ELIPs in photoprotection |
was suggested in |
work done by Hutin et al. (2003) |
|
| photoprotective capacity of red-leaf phenotype |
is smaller |
red leaf phenotype of Cistus creticus |
Cistus creticus |
| anthocyanin accumulation |
may afford some protection by reducing |
excitation pressure |
Cistus creticus |
| diminishing photooxidation through xanthophyll cycle-dependent thermal dissipation |
is one of |
three main mechanisms to diminish photooxidative damage |
|
| photoinhibition of photosynthesis |
requires comparison between |
abaxially anthocyanic versus acyanic tissues |
|
| red individuals of Cistus creticus |
displayed slightly inferior |
photosynthetic and photoprotective capabilities |
Cistus creticus |
| concomitant chlorophyll loss |
may afford some protection by reducing |
excitation pressure |
Cistus creticus |
| ABA |
might play important roles in |
improving light energy distribution and protecting photodamage under stress conditions |
Brassica campestris; Oryza sativa |
| enhancement of NPQ |
is observed by |
protection of PSII against increased production of ROS |
|
| external filtering in photoprotection |
occurs when |
photoprotective pigments serve as a screen |
|
| NPQ levels in HL-acclimated insertional mutants |
were statistically higher than in |
WT at all irradiances from 200 to 1500 μmol m −2 s −1 |
Arabidopsis thaliana |
| (SPPA, SPPA1, AT1G73990) function |
may be related more indirectly to |
one of the photoprotective mechanisms |
Arabidopsis thaliana |
| excessive light energy without efficient energy dissipation |
causes |
leaf damage |
Arabidopsis thaliana |
| Arabidopsis aba 1-6 mutant |
possesses |
constitutively high levels of zeaxanthin |
Arabidopsis thaliana |
| (ELIP2, AT4G14690) |
followed the same basic pattern of abundance as |
(ELIP, ELIP1, AT3G22840) although the overall abundance was much lower |
Arabidopsis thaliana |
| photoprotective effect of anthocyanins |
is slight |
red leaf phenotype of Cistus creticus |
Cistus creticus |
| (EX1, EXE1, AT4G33630) plants |
were more resistant than WT to damage upon treatment with |
low concentrations of 3-(3, 4-dichlorphenyl)-1,1-dimethylurea (DCMU) together with high light intensities |
Arabidopsis thaliana |
| Esteban et al. (2008) |
found no correlation between |
foliar anthocyanin and photoprotection |
|
| light-dependent development of non-regulated non-photochemical energy quenching (Φ NO ) |
was similar in |
the two leaf types |
Crithmum creticus |
| plants treated with both CO2 concentrations |
maintain nearly constant |
NPQ at each of the three measurement times |
Spartina densiflora |
| (ATPAL1, PAL1, AT2G37040) (ATPAL2, PAL2, AT3G53260) double mutant |
is highly sensitive to |
UV-B light |
Arabidopsis thaliana |
| carotenoids |
function in singlet energy dissipation by |
non-photochemical quenching (NPQ) |
|