Cold-Resistant and Cold-Sensitive Maize Lines Differ in the Phosphorylation of the Photosystem II Subunit, CP291 (original) (raw)
Plant physiology, 1997
The effects of low temperature on the relative contributions of the reaction center and the antenna activities to photosystem II (PSII) electron transport were estimated by chlorophyll fluorescence. The inhibition of PSII photochemistry resulted from photo-damage to the reaction center and/or a reduced probability of excitation energy trapping by the reaction center. Although chill treatment did not modify the proportion of the dimeric to monomeric PSII, it destabilized its main light-harvesting complex. Full protection of the reaction center was achieved only in the presence of the phosphorylated PSII subunit, CP29. In a nonphosphorylating genotype the chill treatment led to photoinhibitory damage. The phosphorylation of CP29 modified neither its binding to the PSII core nor its pigment content. Phosphorylated CP29 was isolated by flat-bed isoelectric focusing. Its spectral characteristics indicated a depletion of the chlorophyll spectral forms with the highest excitation transfer ...
Genetic analysis of cold-tolerance of photosynthesis in maize
Plant Molecular Biology, 2004
The genetic basis of cold-tolerance was investigated by analyzing the quantitative trait loci (QTL) of an F 2:3 population derived from a cross between two lines bred for contrasting cold-tolerance using chlorophyll fluorescence as a selection tool. Chlorophyll fluorescence parameters, CO 2 exchange rate, leaf greenness, shoot dry matter and shoot nitrogen content were determined in plants grown under controlled conditions at 25/22°C or 15/13°C (day/night). The analysis revealed the presence of 18 and 19 QTLs (LOD > 3.5) significantly involved in the variation of nine target traits in plants grown at 25/22°C and 15/13°C, respectively. Only four QTLs were clearly identified in both temperatures regimes for the same traits, demonstrating that the genetic control of the performance of the photosynthetic apparatus differed, depending on the temperature regime. A major QTL for the cold-tolerance of photosynthesis was identified on chromosome 6. This QTL alone explained 37.4 % of the phenotypic variance in the chronic photoinhibition at low temperature and was significantly involved in the expression of six other traits, including the rate of carbon fixation and shoot dry matter accumulation, indicating that the tolerance to photoinhibition is a key factor in the tolerance of maize to low growth temperature. An additional QTL on chromosomes 2 corresponded to a QTL identified previously in another population, suggesting some common genetic basis of the cold-tolerance of photosynthesis in different maize germplasms. Abbreviations: CER, carbon exchange rate; cM, centimorgans; DW, dry weight; F PSII , operating quantum efficiency of PSII photochemistry; F v /F m , maximum quantum efficiency of PSII primary photochemistry; F 0 v =F 0 m , trapping efficiency of PSII; LOD, likelihood of odds; PSII, photosystem II; qP, photochemical quenching factor; QTL, quantitative trait loci; SPAD, leaf greenness.
Journal of Photochemistry and Photobiology B: Biology, 1998
The effects of elevated temperatures on the photochemical activities of photosystem 11 (PS II) in situ have been studied for barley leaves using a combination of chlorophyll a fluorescence, delayed fluorescence (DF) in the microsecond range and oxygen evolution rate (OE) Attention is given to the succession of PS II inactivation on donor and acceptor sides and its correlation with reversible and/or irreversible depression of OE. The partial decrease of oxygen evolution at 37S"C (by '23%~ compared with the optimal value at 35°C) is found to be mostly reversible and to correlate with a significant increase of the DF signal. The increase of DF indicates that this moderate level of heat stress preferentially induces PS II donor-side inactivation. A nearly irreversible decline of OE occurs at 42.5-45"C. The corresponding decrease of DF signal, by more than 70% if compared with the DF maximum at 4O"C, can be explained by the structural changes within PS II which prevent the recombination of separated charges (P680 ' Q,,-). Further analysis of chlorophyll a fluorescence supports an idea that this level of heat stress induces significant inactivation of PS II photochemistry on both donor and acceptor sides.
2005
The objective of this study was to elucidate the genetic relationship between the specific leaf area (SLA) and the photosynthetic performance of maize (Zea mays L.) as dependent on growth temperature. Three sets of genotypes: (i) 19 S 5 inbred lines, divergently selected for high or low operating efficiency of photosystem II (U PSII ) at low temperature, (ii) a population of 226 F 2:3 families from the cross of ETH-DL3 · ETH-DH7, and (iii) a population of 168 F 2:4 families from the cross of Lo964 · Lo1016 were tested at low (15/13°C day/ night) or at optimal (25/22°C day/night) temperature. The latter cross was originally developed to study QTLs for root traits. At 15/13°C the groups of S 5 inbred lines selected for high or low U PSII differed significantly for all the measured traits, while at optimal temperature the groups differed only with regard to leaf greenness (SPAD). At low temperature, the SLA of these inbred lines was negatively correlated with U PSII (r = À 0.56, p < 0.05) and SPAD (r = À 0.80, p < 0.001). This negative relationship was confirmed by mapping quantitative trait loci (QTL) in the two mapping populations. A co-location of three QTLs for SLA with QTLs for photosynthesis-related traits was detected in both populations at 15/13°C, while co-location was not detected at 25/22°C. The co-selection of SLA and U PSII in the inbred lines and the co-location of QTL for SLA, SPAD, and U PSII at 15/13°C in the QTL populations strongly supports pleiotropy. There was no evidence that selecting for high U PSII at low temperature leads to a constitutively altered SLA.
Photosynthesis, photoinhibition and low temperature acclimation in cold tolerant plants
Photosynthesis Research, 1993
A b s t r a c t 20 variable fluorescence (F v = F M --F o); F o -minimum fluorescence when all traps are open in light adapted leaves; F M -maximum fluorescence when all traps are closed in light adapted leaves; F v -variable fluorescence in light adapted leaves (Fv= F M -Fo); H -cold hardened state; HL -high-light (1200 prnol m -2 s-') grown plants; LD -plants grown with a 16 h photoperiod; LHC I I b -oligomeric form of the light harvesting complex of PS II; LTs0 -freezing temperature at which 50% of the plants die; MDAmonodehydroascorbate; MV -methylviologen; NH -nonhardened state; PCR -photosynthetic carbon reduction cycle; PGA -phosphoglycerate; PQ -plastoquinone; PSmax -maximum, light saturated rates of photosynthesis; qp -photochemical quenching parameter; qN --nonphotochemical quenching parameter; ~PS H --yield of PS II electron transport; (QA)ox -oxidized form of the primary, stable electron acceptor for PS II; (Qa)rea -reduced form of the primary, stable electron acceptor for PS II; RuBP -ribulose-l,5bisphosphate; SD -plants grown with an 8 h photoperiod; SOD -superoxide dismutase; SPS -sucrose phosphate synthase; SUC-P -sucrose phosphate; TMPD -tetramethylphenylenediamine; TP -triose phosphate.
The use of chlorophyll fluorescence as a screening method for cold tolerance in maize
Photosynthesis Research, 1989
Chlorosis in maize (Zea mays L.) is a common phenomenon in the 12 to 17°C temperature range. A newly developed chlorophyll-fluorescence technique was used to elucidate the underlying subcellular processes of resistance to chlorosis. Four populations were used that were developed by divergent mass selection for contrasting resistance to chlorosis in a cold-tolerant dent and a cold-tolerant flint population. Young plants from the four populations were kept for six days at 17/10, 15/10 and 13/10°C (day/night). After 1, 3 and 6 days various chlorophyll-fluorescence parameters were determined. The measurements were done on leaf 4. Differences were not uniform for all fluorescence properties. The resistant and susceptible populations of the two sets differed for the Q-quenching which is related to the electron transport rate in the chloroplast. For the E-quenching which is related to the Calvin cycle activity, the resistant dent differed significantly from the other three populations. The ratio Fm/Fo (related to the transfer of absorbed light-energy from antennae pigments to reaction centers in the chloroplast) was higher for the resistant dent population than for the susceptible one. The flint types did not differ for this property.
PLANT PHYSIOLOGY, 1988
Characterization of the functional organization of the photochemical apparatus in the light sensitive chlorophyll b-deficient oil yellow-yellow green (OY-YG) mutant of maize (Zea mays) is presented. Spectrophotometric and kinetic analysis revealed substantially lower amounts of the light harvesting complex of photosystem II (LHCII-peripheral) in high light-grown OY-YG thylakoids. However, accumulation of a tightly bound LHCII appears unaffected by the lesion. Changes in photosystem (PS) stoichiometry include lower amounts of PSII with characteristic fast kinetics (PSIIa) and a substantial accumulation of PSII centers with characteristic slow kinetics (PSII,,) in the thylakoid membrane of the OY-YG mutant. Thus, PSII5, is the dominant photosystem in the mutant chloroplasts. In contrast to wild type, roughly 80% of the mutant PSII,, centers are functionally coupled to the plastoquinone pool and are probably localized in the appressed regions of the thylakoid membrane. These centers, designated PSII,J-QB-reducing (QB being the secondary electron quinone acceptor of PSII), are clearly distinct from the typical PSIIJ,-QB-nonreducing centers found in the stroma lamellae of wild-type chloroplasts. It is concluded that the observed changes in the stoichiometry of electrontransport complexes reflect the existence of a regulatory mechanism for the adjustment of photosystem stoichiometry in chloroplasts designed to correct any imbalance in light absorption by the two photosystems.
Photosynthetica, 2006
The influence of chilling (8 o C, 5 d) at two photon flux densities [PFD, L = 200 and H = 500 µmol(photon) m −2 s −1 ] on the gas exchange and chlorophyll fluorescence was investigated in chilling-tolerant and chilling-sensitive maize hybrids (Zea mays L., K383×K130, K185×K217) and one cultivar of field bean (Vicia faba L. minor, cv. Nadwiślański). The net photosynthetic rate (P N) for the both studied plant species was inhibited at 8 o C. P N of both maize hybrids additionally decreased during chilling. Changes in the quantum efficiency of PS2 electron transport (Φ PS2) as a response to chilling and PFD were similar to P N. Measurements of Φ PS2 /Φ CO2 ratio showed that in field bean seedlings strong alternative photochemical sinks of energy did not appear during chilling. However, the high increment in Φ PS2 /Φ CO2 for maize hybrids can indicate reactions associated with chill damage generation. At 8 o C the non-photochemical quenching (NPQ) increased in all plants with chilling duration and PFD. The appearance of protective (q I,p) and damage (q I,d) components of q I and a decrease in q E (energy dependent quenching) took place. NPQ components of field bean and maize hybrids differed from each other. The amount of protective NPQ (q E + q I,p) components as part of total NPQ was higher in field bean than in maize hybrids at both PFD. On 5 th day of chilling, the sum of q E and q I,p was 26.7 % of NPQ in tolerant maize hybrids and 17.6 % of NPQ in the sensitive one (averages for both PFD). The increased PFD inhibited the ability of all plants to perform protective dissipation of absorbed energy. The understanding of the genotypic variation of NPQ components in maize may have implications for the future selection of plants with a high chilling tolerance.