scholarly journals The effects of preharvest LED light, melatonin and AVG treatments on the quality of postharvest snapdragon and vase life

2020 ◽  
pp. 14-19
Author(s):  
Diying Xiang ◽  
Chi Dinh Nguyen ◽  
Liz Felter ◽  
David Clark ◽  
Heqiang Huo
Keyword(s):  
Blue Light ◽  
White Light ◽  
Stem Elongation ◽  
Red Light ◽  
The United States ◽  
Vase Life ◽  
Cut Flowers ◽  
Led Light ◽  
Post Harvesting

Snapdragon (Antirrhinum majus) is one of top ten fresh-cut flowers in the United States; however, its short vase life limits its marketability. The purposes of this study were to test the effects of LED light, exogenous melatonin and one ethylene production inhibitor, AVG, on the quality of pre-harvest snapdragon and the prolongation of vase life after post-harvesting. Our results showed that snapdragon treated with 10 h white light followed by 6 h blue light (WB) inhibited stem elongation and lengths of the inflorescences, reduced the number of florets and vase life. On the contrary, snapdragon treated with 10 h white light, 3 h red light, 3 h blue light (WRB) significantly promoted stem elongation, lengths of the inflorescences, and increased the size and number of florets. The lengths of stems and inflorescences increased significantly in all melatonin treatments while quantity and size of florets only increased with 200 µmol·L-1 melatonin application. Noticeably, vase life was significantly extended with 200 µmol·L-1 melatonin application and shortened with WB treatment. In contrast to melatonin, all AVG treatments resulted in decreases of the floret size; and changes in stem elongation and inflorescence length were only observed in the treatment with 100 µmol·L-1AVG. These results showed that pre-harvest treatment with WBR and melatonin can effectively improve the post-harvest quality of snapdragon flowers and 200 µmol·L-1 of melatonin extended their vase life.

scholarly journals Photosynthesis of the Cyanidioschyzon merolae cells in blue, red, and white light

2020 ◽  
Vol 147 (1) ◽  
pp. 61-73
Author(s):  
Eugeniusz Parys ◽  
Tomasz Krupnik ◽  
Ilona Kułak ◽  
Kinga Kania ◽  
Elżbieta Romanowska
Keyword(s):  
Blue Light ◽  
White Light ◽  
Red Light ◽  
Carbonic Anhydrase Activity ◽  
Compensation Point ◽  
Cyanidioschyzon Merolae ◽  
Rate Of Photosynthesis ◽  
White Control ◽  
Β Carotene

AbstractPhotosynthesis and respiration rates, pigment contents, CO2 compensation point, and carbonic anhydrase activity in Cyanidioschizon merolae cultivated in blue, red, and white light were measured. At the same light quality as during the growth, the photosynthesis of cells in blue light was significantly lowered, while under red light only slightly decreased as compared with white control. In white light, the quality of light during growth had no effect on the rate of photosynthesis at low O2 and high CO2 concentration, whereas their atmospheric level caused only slight decrease. Blue light reduced markedly photosynthesis rate of cells grown in white and red light, whereas the effect of red light was not so great. Only cells grown in the blue light showed increased respiration rate following the period of both the darkness and illumination. Cells grown in red light had the greatest amount of chlorophyll a, zeaxanthin, and β-carotene, while those in blue light had more phycocyanin. The dependence on O2 concentration of the CO2 compensation point and the rate of photosynthesis indicate that this alga possessed photorespiration. Differences in the rate of photosynthesis at different light qualities are discussed in relation to the content of pigments and transferred light energy together with the possible influence of related processes. Our data showed that blue and red light regulate photosynthesis in C. merolae for adjusting its metabolism to unfavorable for photosynthesis light conditions.

scholarly journals Illumination Policies for Stichococcus sp. Cultures in an Optimally Operating Lab-Scale PBR toward the Directed Photosynthetic Production of Desired Products

2021 ◽  
Vol 13 (5) ◽  
pp. 2489
Author(s):  
Paraskevi Psachoulia ◽  
Christos Chatzidoukas
Keyword(s):  
Blue Light ◽  
White Light ◽  
Red Light ◽  
Biomass Concentration ◽  
Biomass Productivity ◽  
Metabolite Profile ◽  
Culture Conditions ◽  
Light Spectrum ◽  
Led Light ◽  
Red Led

The light spectrum effect on the cultivation efficiency of the microalgae strain Stichococcus sp. is explored, as a means of potentially intensifying the biomass productivity and regulating the cellular composition. Stichococcus sp. batch culture experiments, within a 3 L bench-top photobioreactor (PBR), are designed and implemented under different light spectrum profiles (i.e., cool white light (WL), cool white combined with red light (WRL), and cool white combined with blue light, (WBL)). The obtained results indicate that the studied strain is capable of adapting its metabolite profile to the light field to which it is exposed. The highest biomass concentration (3.5 g/L), combined with intense carbohydrate accumulation activity, resulting in a respective final concentration of 1.15 g/L was achieved within 17 days using exclusively cool white light of increasing intensity. The addition of blue light emitting diodes (LED) light, combined with appropriately selected culture conditions, contributed significantly to the massive synthesis and accumulation of lipids, resulting in a concentration of 1.43 g/L and a respective content of 46.13% w/w, with a distinct impact on biomass, carbohydrates and proteins productivity. Finally, a beneficial contribution of red LED light to the protein synthesis is recognized and this can be conditionally amplified provided nitrogen sufficiency in the culture medium.

scholarly journals Single Wavelengths of LED Light Supplement Promote the Biosynthesis of Major Cyclic Monoterpenes in Japanese Mint

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1420
Author(s):  
Takahiro Ueda ◽  
Miki Murata ◽  
Ken Yokawa
Keyword(s):  
Blue Light ◽  
Solid Phase ◽  
Glandular Trichomes ◽  
Red Light ◽  
Glandular Trichome ◽  
Pulse Amplitude ◽  
Light Treatment ◽  
Led Light ◽  
Trichome Formation ◽  
Japanese Mint

Environmental light conditions influence the biosynthesis of monoterpenes in the mint plant. Cyclic terpenes, such as menthol, menthone, pulegone, and menthofuran, are major odor components synthesized in mint leaves. However, it is unclear how light for cultivation affects the contents of these compounds. Artificial lighting using light-emitting diodes (LEDs) for plant cultivation has the advantage of preferential wavelength control. Here, we monitored monoterpene contents in hydroponically cultivated Japanese mint leaves under blue, red, or far-red wavelengths of LED light supplements. Volatile cyclic monoterpenes, pulegone, menthone, menthol, and menthofuran were quantified using the head-space solid phase microextraction method. As a result, all light wavelengths promoted the biosynthesis of the compounds. Remarkably, two weeks of blue-light supplement increased all compounds: pulegone (362% increase compared to the control), menthofuran (285%), menthone (223%), and menthol (389%). Red light slightly promoted pulegone (256%), menthofuran (178%), and menthol (197%). Interestingly, the accumulation of menthone (229%) or menthofuran (339%) was observed with far-red light treatment. The quantification of glandular trichomes density revealed that no increase under light supplement was confirmed. Blue light treatment even suppressed the glandular trichome formation. No promotion of photosynthesis was observed by pulse-amplitude-modulation (PAM) fluorometry. The present result indicates that light supplements directly promoted the biosynthetic pathways of cyclic monoterpenes.

scholarly journals The Preferences of Different Cultivars of Lettuce Seedlings (Lactuca sativa L.) for the Spectral Composition of Light

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1211
Author(s):  
Barbara Frąszczak ◽  
Monika Kula-Maximenko
Keyword(s):  
Chlorophyll Content ◽  
Blue Light ◽  
White Light ◽  
Leaf Shape ◽  
Red Light ◽  
Spectral Composition ◽  
Fresh Weight ◽  
Light Spectrum ◽  
Dark Green ◽  
Relative Chlorophyll Content

The spectrum of light significantly influences the growth of plants cultivated in closed systems. Five lettuce cultivars with different leaf colours were grown under white light (W, 170 μmol m−2 s−1) and under white light with the addition of red (W + R) or blue light (W + B) (230 μmol m−2 s−1). The plants were grown until they reached the seedling phase (30 days). Each cultivar reacted differently to the light spectrum applied. The red-leaved cultivar exhibited the strongest plasticity in response to the spectrum. The blue light stimulated the growth of the leaf surface in all the plants. The red light negatively influenced the length of leaves in the cultivars, but it positively affected their number in red and dark-green lettuce. It also increased the relative chlorophyll content and fresh weight gain in the cultivars containing anthocyanins. When the cultivars were grown under white light, they had longer leaves and higher value of the leaf shape index. The light-green cultivars had a greater fresh weight. Both the addition of blue and red light significantly increased the relative chlorophyll content in the dark-green cultivar. The spectrum enhanced with blue light had positive influence on most of the parameters under analysis in butter lettuce cultivars. These cultivars were also characterised by the highest absorbance of blue light.

scholarly journals Blue Light Improves Vase Life of Carnation Cut Flowers Through Its Effect on the Antioxidant Defense System

2020 ◽  
Vol 11 ◽  
Author(s):  
Mostafa Aalifar ◽  
Sasan Aliniaeifard ◽  
Mostafa Arab ◽  
Mahboobeh Zare Mehrjerdi ◽  
Shirin Dianati Daylami ◽  
...  
Keyword(s):  
Blue Light ◽  
Antioxidant Defense ◽  
Antioxidant Defense System ◽  
Vase Life ◽  
Defense System ◽  
Cut Flowers

(K0.5Na0.5)NbO3:Eu3+/Bi3+: a novel, highly efficient, red light-emitting material with superior water resistance behavior

RSC Advances ◽  
2015 ◽  
Vol 5 (6) ◽  
pp. 4707-4715 ◽  
Author(s):  
Qiwei Zhang ◽  
Haiqin Sun ◽  
Tao Kuang ◽  
Ruiguang Xing ◽  
Xihong Hao
Keyword(s):  
Blue Light ◽  
White Light ◽  
High Performance ◽  
Water Resistance ◽  
Light Emitting Diodes ◽  
Red Light ◽  
Light Emitting ◽  
Highly Efficient ◽  
White Light Emitting Diodes

Materials emitting red light (∼611 nm) under excitation with blue light (440–470 nm) are highly desired for fabricating high-performance white light-emitting diodes (LEDs).

scholarly journals Identification and expression of the trehalose-6-phosphate synthase gene family members in tomato exposed to different light spectra

2017 ◽  
Vol 69 (1) ◽  
pp. 93-101
Author(s):  
Zexiong Chen ◽  
Juan Lou
Keyword(s):  
Plant Growth ◽  
Blue Light ◽  
White Light ◽  
Growth And Development ◽  
Light Quality ◽  
Red Light ◽  
Floral Transition ◽  
Stem Length ◽  
Pcr Analysis ◽  
Phosphate Synthase

Light is the source of energy for plants. Light wavelengths, densities and irradiation periods act as signals directing morphological and physiological characteristics during plant growth and development. To evaluate the effects of light wavelengths on tomato growth and development, Solanum lycopersicum (cv. micro-Tom) seedlings were exposed to different light-quality environments, including white light and red light supplemented with blue light (at ratios of 3:1 and 8;1, respectively). Tomatoes grown under red light supplemented with blue light displayed significantly shorter stem length, a higher number of flower buds and rate of fruit set, but an extremely late flowering compared to white-light-grown plants. To illustrate the mechanism underlying the inhibition of stem growth and floral transition mediated by red/blue light, 10 trehalose-6-phosphate synthase (TPS) genes were identified in tomato, and bioinformatics analysis was performed. qRT-PCR analysis showed that SlTPSs were expressed widely throughout plant development and SlTPS1 was expressed at extremely high levels in stems and buds. Further analysis of several flowering-associated genes and microRNAs showed that the expressions of SlTPS1, SlFT and miR172 were significantly downregulated in tomato grown under red and blue light compared with those grown under white light, whereas miR156 transcript levels were increased. A regulatory model underlying vegetative growth and floral transition regulated by light qualities is presented. Our data provide evidence that light quality strongly affects plant growth and phase transition, most likely via the TPS1-T6P signaling pathway.

scholarly journals Hormonal endogenous changes in response to the exogenous 6-benzylaminopurine application in pre- and post-harvesting lilium flower stalks

2021 ◽  
Author(s):  
Gunther Mantilla ◽  
Gabriel Antonio Lorenzo ◽  
Libertad Mascarini
Keyword(s):  
Environmental Variables ◽  
Lilium Longiflorum ◽  
Vase Life ◽  
Plant Responses ◽  
Biological Processes ◽  
Hormonal Changes ◽  
Post Harvest ◽  
Growth Development ◽  
Post Harvesting

Abstract Phyto-hormones play a key role in regulating plant responses to stress. Cytokines are a type of phyto-hormones involved in the regulation of many important biological processes related to growth, development, and response to environmental variables. The exogenous application of cytokines increases the possibility of delaying senescence; however, this is a physiological process, and, under certain conditions, degradation processes may be triggered. The effect of 6-bencilaminopurine application and the endogenous hormonal changes involved in lilies floral stalks after their cutting were studied. In order to improve vase life and quality of Lilium longiflorum ‘Brindisi’ flower stalks, they were sprayed with 6-BAP, at a concentration of 300 ppm at pre-harvest, post-harvest, and pre- and post-harvest stages. After that, they were compared to non-sprayed control stalks. The application of 6-BAP caused endogenous hormonal changes in abscisic acid and cytokinin levels, and the most effective treatment was pre-harvest spraying. This treatment proved to be an appropriate method to improve the stalk tolerance to post-harvest stress as it delayed the appearance of senescence symptoms and reduced the speed of chlorophyll degradation with differences of up to 10% with respect to untreated stalks. In addition, the opening of flowers was delayed by up to 2 days, although there were no significant differences in total vase life.

Photocontrol of Chloroplast Lipids in Fern Gametophytes

1986 ◽  
Vol 41 (5-6) ◽  
pp. 591-596 ◽  
Author(s):  
Stefan Kraiss ◽  
Armin R. Gemmrich
Keyword(s):  
Linoleic Acid ◽  
Linolenic Acid ◽  
Blue Light ◽  
White Light ◽  
Red Light ◽  
Acid Synthesis ◽  
Anemia Phyllitidis ◽  
The Individual ◽  
Hexadecatrienoic Acid ◽  
Fern Gametophytes

In the gametophyte of the fern Anemia phyllitidis synthesis of linolenic acid esterified in monogalactosyldiglyceride requires light. By induction-reversion experim ents it could be demonstrated that this light-dependent step is mediated by phytochrome. There is also evidence for phytochrome control of galactolipid and hexadecatrienoic acid synthesis. In continuous blue light the synthesis of linolenic acid is inhibited and linoleic acid accumulates. It is concluded that the blue light photoreceptor affects an inhibition of linoleic acid desaturase. In continuous blue light chloroplasts contain abundant multilayered thylakoids, the grana regions are not as distinct as in white light, and membranes appear less appressed. In continuous red light the membranes are reduced in number and contain less grana-like appressions. It is concluded that both photoreceptors are necessary for a coordinate synthesis and assembly of the individual components of the chloroplast membrane.

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