scholarly journals Genetic separation of phototropism and blue light inhibition of stem elongation.

1992 ◽  
Vol 100 (1) ◽  
pp. 267-271 ◽  
Author(s):  
E Liscum ◽  
J C Young ◽  
K L Poff ◽  
R P Hangarter
Keyword(s):  
Blue Light ◽  
Stem Elongation ◽  
Light Inhibition

The influence of red and blue light on the rate of photosynthesis and the CO2 compensation point at various oxygen concentrations

1970 ◽  
Vol 48 (6) ◽  
pp. 1251-1257 ◽  
Author(s):  
N. P. Voskresenskaya ◽  
G. S. Grishina ◽  
S. N. Chmora ◽  
N. M. Poyarkova
Keyword(s):  
Nicotiana Tabacum ◽  
Blue Light ◽  
Photosynthetic Rate ◽  
Prolonged Exposure ◽  
Red Light ◽  
Compensation Point ◽  
Gas Analyzer ◽  
Co2 Compensation Point ◽  
Rate Of Photosynthesis ◽  
Light Inhibition

Apparent photosynthesis of attached leaves of Phaseolus vulgaris, Vicia faba, Pisum sativum, and Nicotiana tabacum at various intensities of blue and red light was measured by infrared CO2 gas analyzer in a closed system. Simultaneously the CO2 compensation point was measured.It was found that light-limited photosynthetic rate in blue light was equal to or more than that in red light. Inhibition of photosynthesis, which sometimes occurred at light-saturated intensities of blue light, could be avoided by addition of red light, prolonged exposure of the plants to blue light, or by lowering the O2 concentration. Accordingly, the increase of photosynthetic rate due to change of O2 concentration from 21 to 3% O2 is higher in blue light only when photosynthesis is inhibited by blue light at 21% O2. The data on the action of blue and red light on the CO2 compensation point seems to exclude the activation of photorespiration by blue light.The possible effects of blue light on apparent photosynthesis are discussed on the basis of the results presented.

scholarly journals Far-red and Blue Light Synergistically Mitigate Intumescence Injury of Tomato Plants Grown Under Ultraviolet-deficit Light Environment

HortScience ◽  
2016 ◽  
Vol 51 (6) ◽  
pp. 712-719 ◽  
Author(s):  
Tomomi Eguchi ◽  
Ricardo Hernández ◽  
Chieri Kubota
Keyword(s):  
Blue Light ◽  
Stem Elongation ◽  
Light Treatment ◽  
Light Environment ◽  
Photon Flux ◽  
Physiological Disorder ◽  
Tomato Plants ◽  
Light Emitting ◽  
Number Of Leaves ◽  
Percent Number

Intumescence injury is an abiotic-stress-induced physiological disorder associated with abnormal cell enlargement and cell division. The symptom includes blister- or callus-like growths on leaves, which occur on sensitive cultivars of tomato when they are grown under ultraviolet (UV)-deficit light environment, such as light-emitting diodes (LEDs). Previous studies suggest that intumescence can be reduced by increasing far-red (FR) or blue light. In the present study, effects of end-of-day FR (EOD-FR) light and high blue photon flux (PF) ratio during the photoperiod on intumescence injury were examined using ‘Beaufort’ interspecific tomato rootstock seedlings (Solanum lycopersicum × Solanum habrochaites), a cultivar highly susceptible to intumescence injury. Our study showed that EOD-FR light treatment moderately suppressed intumescence injury. Using EOD-FR light treatment, the percent number of leaves exhibiting intumescences was reduced from 62.0–70.7% to 39.4–43.1%. By combining high blue PF ratio (75%) during the photoperiod and EOD-FR light treatment, the percent number of leaves exhibiting intumescences was further suppressed to 5.0%. Furthermore, the combination of high blue PF ratio and EOD-FR light treatment inhibited undesirable stem elongation caused by EOD-FR light treatment. We found that high blue PF ratio during the photoperiod combined with a small dose of EOD-FR lighting (≈1 mmol·m−2·d−1 provided by 5.2 µmol·m−2·s−1 FR PF for 3.3 minutes) could inhibit the problematic intumescence injury of tomato plants grown under LEDs without negatively influencing growth or morphology.

scholarly journals Blue Wavelengths from LED Lighting Increase Nutritionally Important Metabolites in Specialty Crops

HortScience ◽  
2015 ◽  
Vol 50 (9) ◽  
pp. 1285-1288 ◽  
Author(s):  
Dean A. Kopsell ◽  
Carl E. Sams ◽  
Robert C. Morrow
Keyword(s):  
Blue Light ◽  
Protein Complexes ◽  
Light Emitting Diode ◽  
Stem Elongation ◽  
Plant Production ◽  
Plant Responses ◽  
Vegetable Crops ◽  
Specialty Crops ◽  
Led Lighting ◽  
Primary And Secondary Metabolites

Light is one of the most important environmental stimuli impacting plant growth and development. Plants have evolved specialized pigment-protein complexes, commonly referred to as photoreceptors, to capture light energy to drive photosynthetic processes, as well as to respond to changes in light quality and quantity. Blue light can act as a powerful environmental signal regulating phototropisms, suppression of stem elongation, chloroplast movements, stomatal regulation, and cell membrane transport activity. An emerging application of light-emitting diode (LED) technology is for horticultural plant production in controlled environments. Work by our research group is measuring important plant responses to different wavelengths of light from LEDs. We have demonstrated positive impacts of blue wavelengths on primary and secondary metabolism in microgreen and baby leafy green brassica crops. Results show significant increases in shoot tissue pigments, glucosinolates, and essential mineral elements following exposure to higher percentages of blue wavelengths from LED lighting. The perception of energy-rich blue light by specialized plant photoreceptors appears to trigger a cascade of metabolic responses, which is supported by current research showing stimulation of primary and secondary metabolite biosynthesis following exposure to blue wavelengths. Management of the light environment may be a viable means to improve concentrations of nutritionally important primary and secondary metabolites in specialty vegetable crops.

scholarly journals Low-activity Cryptochrome 1 Plays a Role in Promoting Stem Elongation and Flower Initiation of Mature Arabidopsis under Blue Light Associated with Low Phytochrome Activity

2021 ◽  
Author(s):  
Yun Kong ◽  
Youbin Zheng
Keyword(s):  
Transgenic Plants ◽  
High Activity ◽  
Blue Light ◽  
Stem Elongation ◽  
Flower Initiation ◽  
Wild Type ◽  
Cryptochrome 1 ◽  
Low Activity

To clarify whether cryptochrome contributes to stem elongation and flowering promoted by blue lights associated with low phytochrome activity, wild-type Arabidopsis was compared with its cryptochrome-deficient mutants and cryptochrome-overexpressing transgenic plants. Results indicated that the promotion effects were mainly related to low CRY1 activity, despite partial involvement of high-activity CRY2.

scholarly journals Phytochrome contributes to blue-light-mediated stem elongation and associated shade-avoidance response in mature Arabidopsis plants

2020 ◽  
Author(s):  
Yun Kong ◽  
Youbin Zheng
Keyword(s):  
Avoidance Response ◽  
Blue Light ◽  
Stem Elongation ◽  
Growth Trait ◽  
Stem Length ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Shade Avoidance ◽  
Wild Type ◽  
Avoidance Responses

AbstractOur recent studies on ornamental plants and microgreens indicate that blue-light-mediated stem elongation is related to phytochrome activity, which was based on the calculated phytochrome photoequilibrium. To examine whether phytochromes really contribute to the blue light’s effect, plant phenotypic responses were investigated in wild type Arabidopsis (Col-0), and its quintuple phytochrome (phyA phyB phyC phyD phyE) mutant plants under the following light treatments: (1) R, a pure red light from 660-nm LED; (2) B, a pure blue light from 455-nm LED; (3) BR, a impure blue light from LED combination of 94% B and 6% R; and (4) BRF, another impure blue light from LED combination of BR and 6 µmol m−2 s−1 of FR (735 nm). For all the light treatments, a photosynthetic photon flux density of ≈100 μmol m−2 s−1 were provided by 24-h lighting daily inside a walk-in growth chamber, which had an air temperature of ≈ 23 °C. The calculated phytochrome photoequilibrium was 0.89, 0.50, 0.69, and 0.60 for R, B, BR, and BRF, respectively, indicating a higher phytochrome activity under R and BR than B and BRF. After 18 days of light treatment, B or BRF increased main stem length in wild-type plants compared with R, but BR had an inhibition effect similar to R. Also, B and BRF relative to R or BR induced earlier flowering and reduced leaf size in wild type plants, showing typical shade-avoidance responses. In phytochrome-deficient mutant plants, the above shade-avoidance responses were inhibited under B or BRF, and induced under BR. However, as an exception, hypocotyl length, a growth trait during the de-etiolation stage, was reduced under B, BR and BRF vs. R regardless of phytochrome absence. It suggests that for mature Arabidopsis plants, phytochrome plays an active role in blue-light-mediated stem elongation and associated shade-avoidance response.

Phytochrome contributes to blue-light-mediated stem elongation and flower initiation in mature Arabidopsis thaliana plants

2021 ◽  
Author(s):  
Yun Kong ◽  
Youbin Zheng
Keyword(s):  
Arabidopsis Thaliana ◽  
Blue Light ◽  
Stem Elongation ◽  
Growth Trait ◽  
Stem Length ◽  
Photon Flux ◽  
Flower Initiation ◽  
Shade Avoidance ◽  
Wild Type ◽  
Avoidance Responses

To examine whether phytochromes contribute to blue-light-mediated stem elongation, plant phenotypic responses were investigated in wild type Arabidopsis thaliana (Col-0), and its quintuple phytochrome (phyA phyB phyC phyD phyE) mutant plants under the following light treatments: (1) R, a pure red light from 660-nm LED; (2) B, a pure blue light from 455-nm LED; (3) BR, a impure blue light from LED combination of 94% B and 6% R; and (4) BRF, another impure blue light from LED combination of BR and 6 µmol m−2 s−1 of FR (735 nm). A photosynthetic photon flux density of ≈100 μmol m−2 s−1 was provided for all the light treatments. The calculated phytochrome photoequilibrium was 0.89, 0.50, 0.69, and 0.60 for R, B, BR, and BRF, respectively, indicating a higher phytochrome activity under R and BR than B and BRF. After 18 days of light treatment, B or BRF increased main stem length in wild-type plants compared with R, but BR had an inhibition effect similar to R. Also, B and BRF relative to R or BR induced earlier flowering and reduced leaf size in wild type plants, showing typical shade-avoidance responses. In phytochrome-deficient mutant plants, the above shade-avoidance responses were inhibited under B or BRF. However, hypocotyl length, a growth trait characterizing the de-etiolation stage, was reduced under B, BR and BRF vs. R regardless of phytochrome absence. These findings suggest that for mature Arabidopsis plants, phytochrome plays a role in blue-light-mediated stem elongation and the associated shade-avoidance responses.

BLUE LIGHT INHIBITS STEM ELONGATION OF CHRYSANTHEMUM

2006 ◽  
pp. 363-368 ◽  
Author(s):  
H. Shimizu ◽  
Z. Ma ◽  
S. Tazawa ◽  
M. Douzono ◽  
E.S. Runkle ◽  
...  
Keyword(s):  
Blue Light ◽  
Stem Elongation
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