Characterization of a Microsecond Intermediate in the Laser Flash Photolysis of Small Phytochrome From Oat

Braslavsky, Silvia E.; Matthews, J. Ioan; Herbert, Hans; Kok, de J.; Spruit, C. J. P.; Schaffner, Kurt

doi:10.1111/j.1751-1097.1980.tb02562.x

Cited by 51 publications

(13 citation statements)

References 14 publications

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“…In particular, the difference spectrum at -140°C (Fig. 6) corresponds to the difference spectrum at about 10 ns after the flash, that at -85°C (not shown) to that at about 500 \is, and that at -4rC (not shown) to that at about 100-200 ms, after the flash (see Linschitz et al 1966, Braslavsky et al 1980, Shimazaki et al 1980, Pratt et al 1982. The difference spectrum at -140°C (Fig.…”

Section: Resultsmentioning

confidence: 94%

“…The intermediate steps of the photoconversions between the P, and the P,, form of phytochrotne have tnainly been investigated by flash photolysis and low temperature spectroscopy (review: Keodrick and Spruit 1977). While earlier work on the kinetics after flash photolysis has been repeated and extended by several authors (Braslavsky et al 1980, Shitnazaki et al 1980, Cordonnier et al 1981, Pratt et al 1982),, only litnited data are available for low temperature spectroscopy of phytochrome forms (Song et al 1981). Pratt aod Butler (1968) discussed some of the problems of low tetnperature spectroscopy (e.g.…”

Section: Introductionmentioning

confidence: 99%

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Low temperature spectroscopy of phytochrome: P_r, P_fr and intermediates

Rüdiger¹,

Thümmler²

1984

Physiologia Plantarum

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Phytochrome (120 kdalton) was isolated from etiolated seedlings of Avena sativa L. cv. Pirol (Baywa, München). Low temperature spectra between −17°C and −160°C are recorded for Pr, Pfr, and irradiated phytochrome samples. The temperature‐dependence of the Pr and Pfr absorption spectra is described. Difference spectra of such temperature effects can erroneously be interpreted as difference spectra of intermediates. Probable absorption spectra of intermediates are calculated from the spectra of irradiated Pr or Pfr, respectively. The calculated spectral data are compared with published data on phytochrome intermediates.

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Section: Resultsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Low temperature spectroscopy of phytochrome: P_r, P_fr and intermediates

Rüdiger¹,

Thümmler²

1984

Physiologia Plantarum

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“…The second harmonic of a Nd-Yag DLPY2 laser was used to pump a System 2000 wavelength- tunable (0.1 cm-I) dye laser (J.K. Lasers, Rugby, England; for more details see Braslavsky et al, 1980). The pulse duration was 15 ns.…”

Section: Methodsmentioning

confidence: 99%

INDUCTION OF CHLOROPLAST MOVEMENT IN THE ALGA Mougeotia BY POLARIZED NANOSECOND DYE‐LASER PULSES*^†

Scheuerlein

Braslavsky

1987

Photochem & Photobiology

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Chloroplast movement of white‐light treated alga Mougeotia was induced by 15‐ns dye‐laser pulses (620‐690 nm). A single pulse, polarized perpendicular to the cell axis, does not induce a significant response, although full response can be obtained when the same fluence is applied during a 30‐s irradiation. However, for 620 and 660 nm perpendicularly polarized flash irradiation results in a significant response, if the total fluence is given by 2 consecutive flashes with 2‐s dark interval (double‐flash effect), and full response can be obtained by poly‐flash induction. Flashes of 690 nm in no case induce a response. Similar to the case of lettuce‐seed germination (Scheuerlein and Braslavsky, 1985), the establishment of a photochromic system between Pr and the very early intermediates (= lumi‐R) during the 15‐ns laser pulse can explain the results. At 690 nm, the photochromic system is shifted more extensively to Pr than at shorter wavelengths; thus, Pfr formation is strongly diminished. At shorter wavelengths (620 and 660 nm) the inhibition of Pfr formation by the existence of this photochromic system is smaller. The results are compatible with parallel dipole moments of the chromophores in Pr and in the first intermediates. A smaller but still significant response is obtained for repeated pulses of 660‐nm light, polarized parallel to the cell axis. These results are explained by a gradient in light sensitivity around the cell axis (induced by the white‐light pretreatment) and an increasing Plr concentration, established around the cell axis, as a function of the number of pulses.

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“…The mutual conversion of both involves several inter mediate steps which h a \e mainly been character ized by their difference spectra [1][2][3][4][5][6][7]. We have recently obtained the first data on absolute spectra of intermediates [8].…”

Section: Introductionmentioning

confidence: 99%

Absorption Spectra of Phytochrome Intermediates

Eilfeld¹,

Rüdiger²

1985

Zeitschrift Für Naturforschung C

100

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Native phytochrome (124kdalton) was isolated from etiolated seedlings o f Avena sativa L. cv. Pirol (Baywa, Munich). From low temperature spectra (0°C to -1 6 5°C ) o f phytochrom e samples irradiated either with red or far-red light, spectra o f interm ediates were calculated. Both absorption bands o f the phytochrome chromophore were reported. On the pathway P r -i V r , native phytochrome does not form a bleached interm ediate (m eta-R b) in contrast to degraded phytochrome. An additional intermediate, meta-Rc ( / max = 725 nm), is form ed instead. On the reverse path way only two intermediates were found, lum i-F and m eta-F. O scillator strengths' values were calculated and interpreted in terms o f chromophore conform ation. A schem e o f interm ediates for native phytochrome is presented.

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Characterization of a Microsecond Intermediate in the Laser Flash Photolysis of Small Phytochrome From Oat

Cited by 51 publications

References 14 publications

Low temperature spectroscopy of phytochrome: P_r, P_fr and intermediates

Low temperature spectroscopy of phytochrome: P_r, P_fr and intermediates

INDUCTION OF CHLOROPLAST MOVEMENT IN THE ALGA Mougeotia BY POLARIZED NANOSECOND DYE‐LASER PULSES*^†

Absorption Spectra of Phytochrome Intermediates

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Characterization of a Microsecond Intermediate in the Laser Flash Photolysis of Small Phytochrome From Oat

Cited by 51 publications

References 14 publications

Low temperature spectroscopy of phytochrome: Pr, Pfr and intermediates

Low temperature spectroscopy of phytochrome: Pr, Pfr and intermediates

INDUCTION OF CHLOROPLAST MOVEMENT IN THE ALGA Mougeotia BY POLARIZED NANOSECOND DYE‐LASER PULSES*†

Absorption Spectra of Phytochrome Intermediates

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Low temperature spectroscopy of phytochrome: P_r, P_fr and intermediates

Low temperature spectroscopy of phytochrome: P_r, P_fr and intermediates

INDUCTION OF CHLOROPLAST MOVEMENT IN THE ALGA Mougeotia BY POLARIZED NANOSECOND DYE‐LASER PULSES*^†