scholarly journals End-of-day Far-red Light Quality and Dose Requirements for Tomato Rootstock Hypocotyl Elongation

HortScience ◽  
2010 ◽  
Vol 45 (10) ◽  
pp. 1501-1506 ◽  
Author(s):  
Po-Lung Chia ◽  
Chieri Kubota
Keyword(s):  
Light Quality ◽  
Dose Range ◽  
Red Light ◽  
Dry Weight ◽  
Light Dose ◽  
Hypocotyl Elongation ◽  
Type Model ◽  
Saturation Curve ◽  
Hypocotyl Length ◽  
Incandescent Light

Plant morphology control is a critical technique in commercial greenhouse transplant production. Light treatment at the end of the day affects a phytochrome-regulated response affecting plant height among other characteristics and has been studied by biologists for many years. Recognizing the need to produce long hypocotyls in vegetable grafting, effects of end-of-day far-red (EOD-FR) light on tomato rootstock hypocotyl elongation were investigated. Two commercial rootstock cultivars, Aloha (Solanum lycopersicum) and Maxifort (S. lycopersicum × S. habrochaites), were used for the experiments examining responses to EOD-FR light quality [red to far-red ratio (R/FR)] and EOD-FR light dose in a greenhouse environment. In the EOD-FR light quality experiment using ‘Aloha’ seedlings, incandescent light (R/FR = 0.47) induced significant hypocotyl elongation (20%) compared with the untreated control. Incandescent light with a spectral cut filter (reducing R/FR to 0.05) induced a greater hypocotyl elongation (44%) than unfiltered light, confirming the importance of use of light with a lower R/FR (or purer FR) light source in EOD-FR treatments. In the experiment on EOD-FR light dose–response, hypocotyl elongation of both ‘Aloha’ and ‘Maxifort’ was increased by increasing FR intensity as well as FR treatment duration at a lower dose range. The dose saturation curve of hypocotyl length was well described using a Michaelis-Menten-type model with FR dose (in mmol·m−2·d−1) as an independent variable. The model-based estimation of 90% saturating FR light dose for ‘Aloha’ and ‘Maxifort’ was 5 to 14 mmol·m−2·d−1 and 8 to 15 mmol·m−2·d−1, respectively, although practical near saturation dose seems to be 2 to 4 mmol·m−2·d−1 for both cultivars. None of the EOD-FR treatments affected plant dry weight, stem diameter, or plastochron index. Hence, elongation was achieved without compromising growth and development. EOD-FR was shown to be an effective non-chemical means allowing transplant propagation industry to produce long hypocotyls for grafting use.

scholarly journals Interactive Effects of Light Quality and Temperature on Arabidopsis Growth and Immunity

2020 ◽  
Vol 61 (5) ◽  
pp. 933-941
Author(s):  
Xiaoying Liu ◽  
Chunmei Xue ◽  
Le Kong ◽  
Ruining Li ◽  
Zhigang Xu ◽  
...  
Keyword(s):  
Disease Resistance ◽  
Blue Light ◽  
Light Quality ◽  
Red Light ◽  
Complex Interaction ◽  
Hypocotyl Elongation ◽  
Interactive Effects ◽  
Phytochrome B ◽  
Light Conditions ◽  
Effects Of Temperature

Abstract We report here the interactive effects of three light qualities (white, red and blue) and three growth temperatures (16�C, 22�C and 28�C) on rosette growth, hypocotyl elongation and disease resistance in Arabidopsis thaliana. While an increase in temperature promotes hypocotyl elongation irrespective of light quality, the effects of temperature on rosette growth and disease resistance are dependent on light quality. Maximum rosette growth rate under white, red and blue light are observed at 28�C, 16�C and 22�C, respectively. The highest disease resistance is observed at 16�C under all three light conditions, but the highest susceptibility is observed at 28�C for white light and 22�C for red and blue light. Interestingly, rosette growth is inhibited by phytochrome B (PHYB) under blue light at 28�C and by cryptochromes (CRYs) under red light at 16�C. In addition, disease resistance is inhibited by PHYB under blue light and promoted by CRYs under red light. Therefore, this study reveals a complex interaction between light and temperature in modulating rosette growth and disease resistance as well as the contribution of PHYB and CRY to disease resistance.

scholarly journals Stomatal opening and growth in tomato seedlings treated with different proportions of red and blue light

2019 ◽  
Vol 99 (5) ◽  
pp. 688-700 ◽  
Author(s):  
Junwei Yang ◽  
Tingting Liang ◽  
Lu Liu ◽  
Tonghua Pan ◽  
Zhirong Zou
Keyword(s):  
Blue Light ◽  
Light Quality ◽  
Red Light ◽  
Chloroplast Ultrastructure ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Stomatal Opening ◽  
Detailed Knowledge ◽  
Tomato Seedlings

Stomatal opening/closure plays a key role in balancing a plant’s need to conserve water, while still allowing for the exchange of photosynthetic and respiratory gasses with the atmosphere. Stomatal opening/closure can be induced by differences in light quality but a detailed knowledge of the role of light in stomatal regulation in tomato is limited. In this study, we evaluated red and blue light-dependent stomatal opening processes in tomato seedlings and explored the mechanisms involved using different light-quality treatments. After 10 h of darkness, tomato seedlings were subjected to the following five treatments: monochromatic red light (R), 33% blue (2R1B), 50% blue (1R1B), 67% blue (1R2B), and monochromatic blue light (B) at 200 μmol m−2s−1light intensity. The highest stomatal conductance recorded were for 1R1B. Stomatal aperture under 1R1B showed a 92.8% increase after 15 min and a 28.6% increase after 30 min compared with under R alone. Meanwhile, the study shows that the expressions of the plasma membrane H+-ATPase in the leaf were regulated by different proportions of blue light. The results show that the expressions of HA1 and HA4 increased under 1R1B and 1R2B after 15 min of exposure compared with under R alone. Under 1R1B, our results also show net photosynthesis increased compared with R and B after longer treatments, which may be related to chloroplast ultrastructure, and leaf dry weight increased compared with under 1R2B or B alone, but there were no differences under the R and 2R1B light treatments.

Red and far-red light influence carbon partitioning, growth and flowering of bahia grass (Paspalum notatum)

1995 ◽  
Vol 125 (3) ◽  
pp. 355-359 ◽  
Author(s):  
F. J. Marousky ◽  
F. Blondon
Keyword(s):  
Light Quality ◽  
Dark Period ◽  
Leaf Growth ◽  
Red Light ◽  
Dry Weight ◽  
Paspalum Notatum ◽  
Starch Accumulation ◽  
Long Day ◽  
Bahia Grass ◽  
Short Days

SUMMARYBahia grass (Paspalum notatum Flugge) plants were grown in growth chambers at Gif, France, and at Gainesville in Florida, demonstrating that the species is a long-day plant and greatly influenced by light quality during the photosynthetic period. Flowering occurred in all instances when the middle of the dark period was interrupted with red or red + far-red light. With nightly interruptions of farred light, flowering occurred only when a sufficient quantity of far-red was present during the photosynthetic period. Plants grown under short days with nightly interruptions of red, far-red or red + far-red light had less starch accumulation and greater leaf growth and dry weight than plants grown without nightly light interruptions, whatever the light quality during the photosynthetic period. The treatments did not affect the partitioning of assimilates and flowering in the same way.

scholarly journals Seasonal Efficiency of Supplemental LED Lighting on Growth and Photomorphogenesis of Sweet Basil

2021 ◽  
Vol 12 ◽  
Author(s):  
Jan Andreas Solbach ◽  
Andreas Fricke ◽  
Hartmut Stützel
Keyword(s):  
Blue Light ◽  
Red Light ◽  
Dry Weight ◽  
Light Interception ◽  
Light Dose ◽  
Infrared Light ◽  
Photon Flux ◽  
Natural Light ◽  
Special Aspect ◽  
Light Regimes

For decisions on supplemental lighting a quantitative knowledge of the plants' responses to light under varying conditions is fundamental. In this study, we developed light dose-response curves of growth and morphological traits for Ocimum basilicum L. and examined the effects of light color (blue, red, and white plus far-red) and natural environment (season) on these curves. Four greenhouse experiments were conducted throughout the year to determine the efficiencies of the light regimes on growth and their effects on plant morphology. A special aspect was the photosynthetic efficiency of far-red light. Linear and monomolecular relationships were found for the relationships between plant traits and supplemental light dose. Traits related to biomass productivity increased linearly with light dose whereas some morphological characters showed a saturation behavior. Red light and white plus far-red light were more efficient in plant dry weight production than blue light, and the plants adapted differently to the light qualities: higher biomass under red light was related to a plant architecture more favorable for light capture, i.e., taller plants and bigger leaves. White plus far-red light, on the other hand, increased leaf mass per area (LMA) and light use efficiency (LUE). Blue light resulted in lowest plant light interception and LUE. Considering photosynthetic effects of near-infrared light (PPFD800, 400–800 nm) instead of photosynthetic photon flux density (PPFD700, 400–700 nm) led to strongly reduced efficiencies. Traits related to photosynthesis such as dry weight, LMA and LUE were particularly affected by PPFD800. There were no interactions between the efficiencies of the different light colors and the seasons. Efficiencies of all light regimes were significantly lower during summer compared to spring and winter. Higher dry weight production during summer compared to winter and spring were a consequence of increased light interception rather than changes in LUE. The observed differences in seasonal efficiencies were directly linked to the amount of natural light present as indicated by changes in the ratio of supplemental to natural light.

Pitted morningglory (Ipomoea lacunosa) germination and emergence as affected by environmental factors and seeding depth

Weed Science ◽  
2006 ◽  
Vol 54 (5) ◽  
pp. 910-916 ◽  
Author(s):  
Marcos J. Oliveira ◽  
Jason K. Norsworthy
Keyword(s):  
Red Light ◽  
Soil Surface ◽  
Moisture Stress ◽  
Hypocotyl Elongation ◽  
Burial Depth ◽  
Hypocotyl Length ◽  
Solution Ph ◽  
Wide Range ◽  
Pitted Morningglory ◽  
Ph Range

Laboratory and greenhouse experiments were conducted to determine the effect of light, temperature, solution pH, solution osmotic potential, and oxygen concentration on pitted morningglory germination and radicle plus hypocotyl elongation, and seeding depth on its subsequent emergence. Daily exposure of seed to natural light resulted in lower germination than in darkness, whereas germination was not influenced by brief exposure to red or far-red light. Germination occurred over a wide range of constant temperatures, from 7.5 to 52.5 C, with optimum germination between 20 and 25 C. Germination occurred at solution pH range of 3 to 10 and was optimal from pH 6 to 8. Radicle plus hypocotyl elongation was influenced by the interaction of temperature and solution pH. A combination of acidic medium (pH 6) and high temperature (30 C) resulted in the greatest radicle plus hypocotyl length of 7.6 cm after a 7-d incubation. Germination and radicle plus hypocotyl elongation, averaged over the 15 and 30 C temperature, decreased with increasing moisture stress, with less than 3% normalized germination at −1.0 MPa. Germination was 29, 40, and 51% at 2, 10, and 20% oxygen, respectively, averaged over 15 and 30 C. Germination of seed lying on the soil surface covered with filter paper or without any cover was similar, averaging 64%. Normalized emergence, relative to germination on the soil surface, decreased with increasing burial depth to 4% emergence at 10 cm, with a mean emergence depth of 4.1 cm, averaged across two soil types.

Effects of Light Quality on the Life Cycles of Crabgrass and Barnyardgrass

Weed Science ◽  
1968 ◽  
Vol 16 (1) ◽  
pp. 58-60 ◽  
Author(s):  
Stuart Dunn ◽  
G. K. Gruendling ◽  
Aubrey S. Thomas
Keyword(s):  
Blue Light ◽  
Light Quality ◽  
Energy Levels ◽  
Red Light ◽  
Dry Weight ◽  
Life Cycles ◽  
Order Effects ◽  
Yellow Light ◽  
Digitaria Sanguinalis ◽  
Delayed Flowering

Large Crabgrass (Digitaria sanguinalis (L.) Scop.) and barnyardgrass (Echinochloa crusgalli (L.) Beauv.) plants were grown from seedlings to maturity under five light qualities of equal energy levels. For crabgrass, both fresh and dry weight yields of plant tops grown under red light and under cool white light were significantly greater than those under green, yellow, or blue light. Length of stem followed this same order. Effects of light quality on reproduction were not as consistent; green and blue light caused the largest numbers of seed heads to form, while yellow light delayed flowering and resulted in the least number and weight of seed heads. Somewhat similar responses to light were found with barnyardgrass plants, except that yields under yellow light were close to those under red light for this species. Blue light caused smallest plants in both kinds of weeds.

Competition, light quality and seedling growth of Russian wildrye grass (Psathyrostachys juncea)

2007 ◽  
Vol 55 (1) ◽  
pp. 49-60 ◽  
Author(s):  
P. Jefferson ◽  
R. Muri
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Light Quality ◽  
Red Light ◽  
Dry Weight ◽  
Tiller Number ◽  
Seedling Vigour ◽  
Psathyrostachys Juncea ◽  
Growth Room ◽  
Russian Wildrye

The low seedling vigour of Russian wildrye grass ( Psathyrostachys juncea ) (RWR) limits its use. Shading from durum wheat ( Triticum turgidum ) reduced RWR leaf number, tiller number, leaf area and seedling dry weight in a growth room experiment. Treatments with similar shading differed in tiller number and dry weight, which suggested that light quality may have also contributed to these responses. In a second growth room experiment, light intensity (PAR) and red:far-red light ratio (670:730 nm) were altered by coloured plastic filters suspended above seedlings of Russian wildrye, crested wheatgrass ( Agropyron desertorum ) (CWG) and Dahurian wildrye grass ( Elymus dahuricus ) (DWR). Leaf area, tiller number and dry weight of RWR seedlings were reduced by declining red:far-red light ratio while light intensity differences at similar red:far-red ratio did not affect these variables. CWG exhibited similar responses to declining red:far-red light ratio as RWR, except that it exhibited a seedling weight response to light intensity. DWR tiller number was not responsive to low red:far-red light ratio but rather to low light intensity. However, DWR seedling weight, tiller weight and leaf area were responsive to declining red:far-red light ratio. These results indicate that RWR seedlings are sensitive to light quality changes caused by neighbouring plants.

scholarly journals Effect of light quality and quantity on productivity and phycoerythrin concentration in the cryptophyte Rhodomonas sp.

2021 ◽  
Author(s):  
Christos Latsos ◽  
Jasper van Houcke ◽  
Lander Blommaert ◽  
Gabrielle P. Verbeeke ◽  
Jacco Kromkamp ◽  
...  
Keyword(s):  
Light Quality ◽  
Incident Light ◽  
Red Light ◽  
Green Light ◽  
Dry Weight ◽  
Continuous Illumination ◽  
Light Illumination ◽  
Initial Growth ◽  
Light Conditions ◽  
Significant Difference

AbstractThe cryptophyte Rhodomonas sp. is a potential feed source for aquaculture live feed and resource for phycoerythrin (PE) production. This research investigates the influence of light, both quality and quantity, on the biomass productivity, composition and growth rate of Rhodomonas sp. The incident light intensity used in the experiments was 50 μmolphotons m−2 s−1, irrespective of the colour of the light, and cultivation took place in lab-scale flat-panel photobioreactors in turbidostat mode. The highest productivity in volumetric biomass (0.20 gdry weight L−1 day−1), measured under continuous illumination, was observed under green light conditions. Blue and red light illumination resulted in lower productivities, 0.11 gdry weight L−1 day−1 and 0.02 g L−1 day−1 respectively. The differences in production are ascribed to increased absorption of green and blue wavelength by phycoerythrin, chlorophyll and carotenoids, causing higher photosynthetically usable radiation (PUR) from equal photosynthetically absorbed irradiance (PAR). Moreover, phycoerythrin concentration (281.16 mg gDW−1) was stimulated under red light illumination. Because photosystem II (PSII) absorbs poorly red light, the algae had to induce more pigments in order to negate the lower absorption per unit pigment of the incident available photons. The results of this study indicate that green light can be used in the initial growth of Rhodomonas sp. to produce more biomass and, at a later stage, red light could be implemented to stimulate the synthesis of PE. Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated a significant difference between the cells under different light quality, with higher contents of proteins for samples of Rhodomonas sp. cultivated under green light conditions. In comparison, higher carbohydrate contents were observed for cells that were grown under red and blue light.

scholarly journals The Combination of Selenium and LED Light Quality Affects Growth and Nutritional Properties of Broccoli Sprouts

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4788
Author(s):  
Rui He ◽  
Meifang Gao ◽  
Rui Shi ◽  
Shiwei Song ◽  
Yiting Zhang ◽  
...  
Keyword(s):  
Nutritional Quality ◽  
Light Quality ◽  
Soluble Sugar ◽  
Principal Component ◽  
Dry Weight ◽  
Mineral Elements ◽  
Hypocotyl Length ◽  
Remarkable Change ◽  
Led Light ◽  
Broccoli Sprouts

Selenium (Se) supplement was combined with different LED light qualities to investigate mutual effects on the growth, nutritional quality, contents of glucosinolates and mineral elements in broccoli sprouts. There were five treatments: CK:1R1B1G, 1R1B1G+Se (100 μmol L−1 Na2SeO3), 1R1B+Se, 1R2B+Se, 2R1B+Se, 60 μmol m−2 s−1 PPFD, 12 h/12 h (light/dark). Sprouts under a combination of selenium and LED light quality treatment exhibited no remarkable change fresh weight, but had a shorter hypocotyl length, lower moisture content and heavier dry weight, especially with 1R2B+Se treatment. The contents of carotenoid, soluble protein, soluble sugar, vitamin C, total flavonoids, total polyphenol and contents of total glucosinolates and organic Se were dramatically improved through the combination of Se and LED light quality. Moreover, heat map and principal component analysis showed that broccoli sprouts under 1R2B+Se treatment had higher nutritional quality and health-promoting compound contents than other treatments. This suggests that the Se supplement under suitable LED lights might be beneficial to selenium-biofortified broccoli sprout production.

scholarly journals Integrated Transcriptome and Metabolome Analysis Reveals an Essential Role for Auxin in Hypocotyl Elongation during End-of-Day Far-Red Treatment of Cucurbita moschata (Duch. Ex Lam.)

Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 853
Author(s):  
Qi Liu ◽  
Hanqing Zhang ◽  
Yanhao Mei ◽  
Qi Li ◽  
Yahui Bai ◽  
...  
Keyword(s):  
Essential Role ◽  
Parenchymal Cell ◽  
Red Light ◽  
Hypocotyl Elongation ◽  
Metabolome Analysis ◽  
Hypocotyl Length ◽  
Transport Inhibitor ◽  
Auxin Transport Inhibitor ◽  
Naphthylphthalamic Acid ◽  
Shed Light

Long, robust hypocotyls are important for facilitating greenhouse transplant production. The use of far-red light at the end of the day (end-of-day far-red, EOD-FR) is known to prompt hypocotyl elongation, but the mechanism of EOD-FR-mediated hypocotyl elongation in pumpkin remains unclear. Here, we found that hypocotyl length, parenchymal cell size in hypocotyls, and plant IAA levels were significantly greater in pumpkin after EOD-FR treatment. This effect was counteracted by the application of the polar auxin transport inhibitor 1-N-naphthylphthalamic acid. Integrated transcriptomic and metabolomic analysis of pumpkin hypocotyls revealed that the expression of auxin-related genes changed significantly after EOD-FR treatment, and the contents of the auxin biosynthetic precursors tryptophan and indole were also significantly higher. Our results show that auxin plays an essential role in EOD-FR-mediated hypocotyl elongation, shed light on the mechanisms of EOD-FR mediated hypocotyl elongation, and provide a theoretical basis for the use of EOD-FR in facility cultivation.

Sign in / Sign up

Export Citation Format

Share Document