The effect of light on acid-soluble polysaccharide accumulation in Sclerotium rolfsii Sacc.

1976 ◽  
Vol 22 (7) ◽  
pp. 967-970 ◽  
Author(s):  
R. Michael Miller ◽  
Anthony E. Liberta

A light-stimulated increase in β-1,3 glucan accumulation was observed for Sclerotium rolfsii Sacc. The acid-soluble polysaccharide accumulated in large quantities in 'white' light- and blue light-grown cultures. This polysaccharide also accumulated in both dark- and red light-grown cultures as well. However, the quantities were significantly lower when compared to the 'white' light- and blue light-grown cultures. A greater quantity of polysaccharide accumulated in red light-grown cultures than in dark-grown cultures.

1988 ◽  
Vol 66 (6) ◽  
pp. 1021-1027 ◽  
Author(s):  
Zdenko Rengel ◽  
Herbert A. Kordan

Anthocyanin production in roots and shoots of Zea mays L. seedlings was higher in blue than in red light and was very low in far red light. Under dichromatic irradiation, a phytochrome mediation of a blue-dependent photoreaction was evident. Pretreatments with both white and blue light allowed increased anthocyanin production under subsequent inductive conditions, as did occurs in treatments with continuous blue, red, far red, or white light. It is suggested that the effect of light pretreatments on phytochrome-controlled anthocyanin formation may differ from that controlled by the combination of cryptochrome and phytochrome.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1211
Author(s):  
Barbara Frąszczak ◽  
Monika Kula-Maximenko

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.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Gilor Kelly ◽  
Danja Brandsma ◽  
Aiman Egbaria ◽  
Ofer Stein ◽  
Adi Doron-Faigenboim ◽  
...  

AbstractThe hypocotyls of germinating seedlings elongate in a search for light to enable autotrophic sugar production. Upon exposure to light, photoreceptors that are activated by blue and red light halt elongation by preventing the degradation of the hypocotyl-elongation inhibitor HY5 and by inhibiting the activity of the elongation-promoting transcription factors PIFs. The question of how sugar affects hypocotyl elongation and which cell types stimulate and stop that elongation remains unresolved. We found that overexpression of a sugar sensor, Arabidopsis hexokinase 1 (HXK1), in guard cells promotes hypocotyl elongation under white and blue light through PIF4. Furthermore, expression of PIF4 in guard cells is sufficient to promote hypocotyl elongation in the light, while expression of HY5 in guard cells is sufficient to inhibit the elongation of the hy5 mutant and the elongation stimulated by HXK1. HY5 exits the guard cells and inhibits hypocotyl elongation, but is degraded in the dark. We also show that the inhibition of hypocotyl elongation by guard cells’ HY5 involves auto-activation of HY5 expression in other tissues. It appears that guard cells are capable of coordinating hypocotyl elongation and that sugar and HXK1 have the opposite effect of light on hypocotyl elongation, converging at PIF4.


RSC Advances ◽  
2015 ◽  
Vol 5 (6) ◽  
pp. 4707-4715 ◽  
Author(s):  
Qiwei Zhang ◽  
Haiqin Sun ◽  
Tao Kuang ◽  
Ruiguang Xing ◽  
Xihong Hao

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).


2017 ◽  
Vol 69 (1) ◽  
pp. 93-101
Author(s):  
Zexiong Chen ◽  
Juan Lou

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.


1986 ◽  
Vol 41 (5-6) ◽  
pp. 591-596 ◽  
Author(s):  
Stefan Kraiss ◽  
Armin R. Gemmrich

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.


2021 ◽  
Vol 8 ◽  
Author(s):  
Peian Zhang ◽  
Suwen Lu ◽  
Zhongjie Liu ◽  
Ting Zheng ◽  
Tianyu Dong ◽  
...  

Different light qualities have various impacts on the formation of fruit quality. The present study explored the influence of different visible light spectra (red, green, blue, and white) on the formation of quality traits and their metabolic pathways in grape berries. We found that blue light and red light had different effects on the berries. Compared with white light, blue light significantly increased the anthocyanins (malvidin-3-O-glucoside and peonidin-3-O-glucoside), volatile substances (alcohols and phenols), and soluble sugars (glucose and fructose), reduced the organic acids (citric acid and malic acid), whereas red light achieved the opposite effect. Transcriptomics and metabolomics analyses revealed that 2707, 2547, 2145, and 2583 differentially expressed genes (DEGs) and (221, 19), (254, 22), (189, 17), and (234, 80) significantly changed metabolites (SCMs) were filtered in the dark vs. blue light, green light, red light, and white light, respectively. According to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, most of the DEGs identified were involved in photosynthesis and biosynthesis of flavonoids and flavonols. Using weighted gene co-expression network analysis (WGCNA) of 23410 highly expressed genes, two modules significantly related to anthocyanins and soluble sugars were screened out. The anthocyanins accumulation is significantly associated with increased expression of transcription factors (VvHY5, VvMYB90, VvMYB86) and anthocyanin structural genes (VvC4H, Vv4CL, VvCHS3, VvCHI1, VvCHI2, VvDFR), while significantly negatively correlated with VvPIF4. VvISA1, VvISA2, VvAMY1, VvCWINV, VvβGLU12, and VvFK12 were all related to starch and sucrose metabolism. These findings help elucidate the characteristics of different light qualities on the formation of plant traits and can inform the use of supplemental light in the field and after harvest to improve the overall quality of fruit.


Author(s):  
Niroj Paudel ◽  
Prakash Deep Rai

<p class="abstract"><strong>Background:</strong> Germination of <em>Desmodium triflorum</em> is used for the scarification using the acid is valuable for the different light condition.</p><p class="abstract"><strong>Methods:</strong> The sample was collected as four month of interval of time and the seed is treated with acids with different time.  </p><p class="abstract"><strong>Results:</strong> seeds scarified with sulfuric acids for 10 min before sowing had better germination than those scarified for 5 and 15 min. Among them light qualities, red and white light had slightly promoted effect whereas blue light and dark condition had slightly negative effect on seed germination.</p><p><strong>Conclusions:</strong> In comparison to blue light and dark condition, red light and white light were promoted to percentage germination indicating the role of phytochrome in seed germination of <em>Desmodium triflorum</em>. </p>


2020 ◽  
Vol 143 ◽  
pp. 02033
Author(s):  
Hancheng Guo ◽  
Zhiguo Fang

Effect of light quality, including red light, blue light, white light, red and blue mixing light with 8:1, 8:2 and 8:3, on the growth characteristics and metabolite accumulation of chlorella pyrenoidosa was conducted based on light emitting diode (LED). Results showed that chlorella pyrenoidosa grew best under blue light, and the optical density, specific growth rate and biomass of chlorella pyrenoidosa was about 2.4, 0.10 d-1 and 6.4 g·L-1, respectively, while the optical density of chlorella pyrenoidosa was between 1.0 and 1.7, specific growth rate was between 0.06-0.10 d-1 and biomass was between 2.7 and 3.8 g·L-1 under other light quality after 30 days of cultivation. The optical density, specific growth rate and biomass of chlorella pyrenoidosa was approximately 2.05 times, 1.33 times and 2.06 times under blue light than red light, respectively. Moreover, Red and blue mixing light was conducive to the synthesis of chlorophyll a and carotenoids of chlorella pyrenoidosa, and blue light could promote the synthesis of chlorophyll b. Chlorophyll a and carotenoids content of chlorella pyrenoidosa was 13.5 mg·g-1and 5.8 mg·g-1 respectively under red and blue mixing light with 8:1, while it was 8.4 mg·g-1 and 3.6 mg·g-1 respectively under blue light. Red and blue mixing light was more conducive to protein and total lipid content per dry cell of chlorella pyrenoidosa. Protein and total lipid content was 489.3 mg·g-1 and 311.2 mg·g-1 under red and blue mixing light with 8:3, while it was 400.9 mg·g-1 and 231.9 mg·g-1 respectively under blue light.


2019 ◽  
Vol 53 (2) ◽  
pp. 38-45
Author(s):  
Irem Deniz ◽  
Zeliha Demirel ◽  
Esra Imamoglu ◽  
Meltem Conk Dalay

AbstractInternal illumination systems are being considered for use as an alternative light supply technique in microalgal products. The main goal of the study was to analyze the roles of different light wavelengths in internally illuminated airlift photobioreactors (PBRs) providing the light energy in an efficient way for the biomass production, lipid yield, and fatty acid composition of Amphora capitellata. The maximum chlorophyll-a concentration per unit biomass (2.62 ± 0.16 mg L−1) was obtained under red light, which was only 14% higher than under blue light in internally illuminated airlift PBR, whereas low chlorophyll-a content was found under white light. Maximum specific growth rate of 0.317 day−1, which corresponded to a doubling time of 2.185 days, was obtained under red light for A. capitellata. It was found that lipid content increased with decreasing growth rate for A. capitellata. Palmitic acid (C16:0) and palmitoleic acid (C16:1) were the principal fatty acids accounting for between 31%‐33% and 31%‐32% of total fatty acids, respectively. It is important to underline that red and blue light spectrum ranges contribute to improved biomass growth, whereas white light has the potential to support lipid content of diatoms.


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