Assay of Photomorphogenic Photoreceptors

Pratt, L H

doi:10.1007/978-3-642-68918-5_8

Cited by 21 publications

(26 citation statements)

References 92 publications

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“…Total spectrally active phytochrome levels were determined by adding the change in A of Pr during irradiation with R (AA660) and of Pfr (AA730) during irradiation with FR [A(AA)660-730] after alternating saturating irradiations at 4°C (Pratt, 1983). A Perkin-Elmer Cetus 557 dual-wavelength spectrophotometer fitted with a custom-built automatic radiation unit producing actinic light at 660 and 730 nm, half bandwidth 10 nm, was used.…”

Section: Spectrophotometric Phytochrome Assaymentioning

confidence: 99%

Function of Phytochrome A in Potato Plants as Revealed through the Study of Transgenic Plants

et al. 1995

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We have generated transgenic potato plants (Solanum fuberosum) containing the potato phytochrome protein encoded by the PHYA gene cDNA (phyA) in sense or antisense orientation under the control of the 35s cauliflower mosaic virus promoter. Plants with increased and decreased phyA levels were analyzed. When grown under white light, development and growth of sprouts and plants were barely distinguishable from wild type. Under continuous far-red light, stem extension, leaf expansion, and hook opening of sprouts were accelerated in phyA overexpressors and delayed in antisense plants. Sprouts with reduced phyA levels were less sensitive to red light with regard to stem extension and expression of the small subunit genes for ribulose bisphosphate carboxylase. Under low red 1ight:far-red light ratios, increased phyA levels reduced the stem extension component of the shade-avoidance response, whereas decreased levels led to an increase in the response.

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Section: Spectrophotometric Phytochrome Assaymentioning

confidence: 99%

Function of Phytochrome A in Potato Plants as Revealed through the Study of Transgenic Plants

et al. 1995

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“…Phytochrome photoreversibility was measured at 653 and 720 nm with a custom-built dual-wavelength spectrophotometer similar to that described by Pratt et al (15). One milliunit of phytochrome from green oats is assumed to be equal to 1 mU of phytochrome from etiolated oats (approximately 1 mg) and is defined as the quantity that in 1 mL yields a photoreversible absorbance difference of 1.0 for a 1-cm light path when measured at the above wavelengths after saturating R and FR actinic irradiations (11). Samples were immediately frozen at -800C until prepared for PAGE.…”

Section: Phytochrome Extractions and Measurementmentioning

confidence: 99%

Phytochrome Levels in Light-Grown Avena Change in Response to End-of-Day Irradiations

Stewart¹,

Pratt²,

Cordonnier-Pratt³

1992

Plant Physiol.

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The effect of 15-minute end-of-day irradiations on photoreversible phytochrome levels in light-grown oat (Avena sativa L., cv Garry) seedlings was investigated. Oat seedlings were grown in a cycle of 8 hours of natural daylight and 16 hours of complete darkness, from sowing until harvest at day 10. The level of extractable, photoreversible phytochrome per unit fresh weight was 60% higher after end-of-day far-red irradiation than after either endof-day red irradiation or end-of-day far-red followed by end-ofday red. Seedlings irradiated with end-of-day far-red also exhibited a small but significant increase in shoot height and fresh weight per seedling. Extracts of seedlings given each of these end-of-day treatments were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, electroblotted, and immunostained with monoclonal antibodies specific to different phytochromes.

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“…rates of destruction and dark-reversion) used in the development of the models are based on the results of spectrophotometric assays in vivo. It is known that spectrophotometric assays of phytochrome in vivo have low sensitivity and are adversely affected by various factors (12). Immunological techniques with a much higher sensitivity than that of the spectrophotometric assay are available to measure absolute amounts ofphytochrome (12).…”

Section: Resultsmentioning

confidence: 99%

Light, Temperature, and Anthocyanin Production

Rabino¹,

Mancinelli²

1986

Plant Physiol.

334

213

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Temperature affects the total amount, the time course, and the red/ far-red effectiveness ratio of light-dependent anthocyanin production in Brassica oleracea L. seedlings. Some of the effects of temperature on anthocyanin production in cabbage are in agreement with the predictions of a model proposed by JK Wall and CB Johnson (1983 Planta 159: 387-397) for the effects of temperature on the state of phytochrome and on the expression of phytochrome-mediated high irradiance responses, but others are not. The lack of a complete agreement between experimental results and model predictions might be due to factors related to the experimental system used or to limitations of the model or both.Light-dependent anthocyanin production in young seedlings displays properties typical of HIR2 plant photomorphogenic responses (8,9). Phytochrome is involved in the photoregulation of the HIR (9).Several theoretical models of phytochrome dynamics (2-4, 7, 15, 19) have been developed to explain the HIR in terms of the interaction between photochemical (photoconversion) and nonphotochemical (synthesis, destruction, dark reversion) reactions of phytochrome. In the range of temperatures from 0 to 30°C, phytochrome photoconversion is temperature-independent and the dark reactions are temperature-dependent: for example, the Qlo for phytochrome destruction is about 3 between 5 and 25C (13). Recently, Wall et al. (20) MATERIALS AND METHODSSeeds ofcabbage (Brassica oleracea L., Burpee Red Acre) were sown in Petri dishes on filter paper moistened with distilled H20.For the continuous irradiation treatments (Fig. 1), the seedlings were grown in darkness for 72 h at 14 or 25°C and then exposed 'Partially supported by National Science Foundation grants PCM-8008747 and DMB-8421 187 to A. L. M.

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Assay of Photomorphogenic Photoreceptors

Cited by 21 publications

References 92 publications

Function of Phytochrome A in Potato Plants as Revealed through the Study of Transgenic Plants

Function of Phytochrome A in Potato Plants as Revealed through the Study of Transgenic Plants

Phytochrome Levels in Light-Grown Avena Change in Response to End-of-Day Irradiations

Light, Temperature, and Anthocyanin Production

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