Relative effectiveness and interaction of ultraviolet-B, red and blue light in anthocyanin synthesis of apple fruit

Anthocyanins are plant pigments that are in demand for medicinal and industrial uses. However, anthocyanin production is limited due to the harvest potential of the species currently used as anthocyanin sources. Rough bluegrass (Poa trivialis L.) is a perennial turfgrass known for accumulating anthocyanins, and may have the potential to serve as a source of anthocyanins through artificial light treatments. The objectives of this research were to determine optimal light conditions that favor anthocyanin synthesis in rough bluegrass, and to determine the suitability of rough bluegrass as a source of anthocyanins. When exposed to high-intensity white light, rough bluegrass increased anthocyanin content by 100-fold on average, and anthocyanin contents greater than 0.2% of dry tissue weight were observed in some samples. Blue light, at intensities between 150 and 250 μmol·m−2·s−1, was the only wavelength that increased anthocyanin content. However, when red light was applied with blue light at 30% or 50% of the total light intensity, anthocyanin content was increased compared with blue light alone. Further experiments demonstrated that these results may be potentially due to a combination of photosynthetic and photoreceptor-mediated regulation. Rough bluegrass is an attractive anthocyanin production system, since leaf tissue can be harvested while preserving meristematic tissues that allow new leaves to rapidly grow; thereby allowing multiple harvests in a single growing season and greater anthocyanin yields.

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Expression characterisation of cyclophilin BrROC1 during light treatment and abiotic stresses response in Brassica rapa subsp. rapa ‘Tsuda’

Functional Plant Biology ◽

10.1071/fp18029 ◽

2018 ◽

Vol 45 (12) ◽

pp. 1223 ◽

Cited By ~ 3

Author(s):

Haifang Yan ◽

Bo Zhou ◽

Wei He ◽

Yuzhe Nie ◽

Yuhua Li

Keyword(s):

Blue Light ◽

Brassica Rapa ◽

Abiotic Stresses ◽

Expression Patterns ◽

Transcript Level ◽

Light Treatment ◽

Anthocyanin Synthesis ◽

Root Epidermis ◽

High Or Low Temperature ◽

Level Analysis

ROC1 is a prototypic peptidyl prolyl cis/trans isomerase (PPIase) of the plant cytosol belonging to the large subfamily of cyclophilins that are associated with diverse functions through foldase, scaffolding, chaperoning or other unknown activities. Although many functions of plant cyclophilins have been reported, the molecular basis of stress-responsive expression of plant cyclophilins is still largely unknown. To characterise the roles of BrROC1 during light treatment and their responses in various abiotic stresses, we identified BrROC1 genes and characterised their expression patterns in Brassica rapa subsp. rapa ‘Tsuda’. Our results showed that BrROC1 genes are multi-family genes. Transcript level analysis showed BrROC1-2 expressed higher than BrROC1-1 in 0 to 6-day-old seedlings under natural light. Moreover, BrROC1-2 genes were also induced to highly express in the cotyledon, upper hypocotyls and lower hypocotyls of seedlings under UV-A and blue-light treatment. In addition, the transcript level of BrROC1-1 was higher in pigment tissues than that in unpigment tissues (cotyledon and lower hypocotyl) under UV-A and blue-light treatment. Furthermore, when the unpigment epidermis (shaded light) of 2-month-old ‘Tsuda’ turnip roots was exposed to UV-A light, transcript levels of the BrROC1-1 and BrROC1-2 were significantly increased with time prolongation. These two BrROC1 genes might be involved in UV-A-induced anthocyanin synthesis in the root epidermis of ‘Tsuda’ turnip, which accumulates high levels of anthocyanin. These two BrROC1 genes were also induced to be regulated by abiotic stresses such as high or low temperature, dehydration, osmotic and salt stresses. Then, the results indicate that BrROC1 genes are involved in light induction response and may play important roles in adaptation of plants to various environmental stresses.

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Regulation of Anthocyanin Synthesis in Apple Skin. II. Involvement of Ethylene

Functional Plant Biology ◽

10.1071/pp9770123 ◽

1977 ◽

Vol 4 (1) ◽

pp. 123 ◽

Cited By ~ 13

Author(s):

DJ Chalmers ◽

JD Faragher

Keyword(s):

Production Rate ◽

Ultraviolet Irradiation ◽

Ethylene Production ◽

Control Level ◽

Apple Fruit ◽

Anthocyanin Synthesis ◽

Anthocyanin Formation ◽

Initial Application ◽

Ethylene Production Rate

Ethylene production by immature apple fruit was stimulated by cycloheximide application, u.v. irradiation and wounding. After fruit were treated with 1 and 10 �g ml-1 cycloheximide, the rate of ethylene production increased to 2 and 10 times the control level, respectively. In skin discs cut from whole fruit (wounded tissue), the rate of ethylene production was stimulated to at least 40 times that in whole fruit. This wound-stimulated ethylene production was partially inhibited by an initial application of cycloheximide. Ultraviolet irradiation of whole fruit stimulated the rate of ethylene production to more than 25 times the control rate after 15 min irradiation. In skin discs, u.v. irradiation caused only a 50-100% increase in ethylene production rate. The effects of certain treatments on ethylene were quantitatively comparable with the effects of the same treatments on anthocyanin formation in whole fruit. Ethylene at 30 �l 1-1 stimulated anthocyanin in skin of immature apples by 16%. Possible mechanisms by which ethylene may stimulate anthocyanin synthesis are discussed.

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Suppression of Cucumber Powdery Mildew by Supplemental UV-B Radiation in Greenhouses Can be Augmented or Reduced by Background Radiation Quality

Plant Disease ◽

10.1094/pdis-03-13-0222-re ◽

2014 ◽

Vol 98 (10) ◽

pp. 1349-1357 ◽

Cited By ~ 26

Author(s):

A. Suthaparan ◽

A. Stensvand ◽

K. A. Solhaug ◽

S. Torre ◽

K. H. Telfer ◽

...

Keyword(s):

Powdery Mildew ◽

Blue Light ◽

Background Radiation ◽

Red Light ◽

Ultraviolet B ◽

Disease Suppression ◽

Radiation Quality ◽

Light Emitting ◽

Cucumber Powdery Mildew ◽

Yellow Orange

This study demonstrates that the spectral quality of radiation sources applied with ultraviolet-B (UV-B; background radiation) affects the suppression of cucumber powdery mildew (Podosphaera xanthii) by UV-B. Suppression provided by daily UV-B exposure of 1 W/m2 for 10 min was greatest in the presence of red light or by a complete lack of background light, and powdery mildew suppression was least in the presence of ultraviolet-A (UV-A) or blue radiation compared with plants exposed only to 16 h of daily natural light supplemented with high-pressure sodium lamps that supply broad-spectrum radiation with peaks in the yellow-orange region. Exposure of powdery mildew-inoculated plants to supplemental red light without UV-B, beginning at the end of the daylight period, also reduced disease severity; however, supplemental blue light applied in the same fashion had no effect. Daily application of UV-B at 1 W/m2 beginning on the day of inoculation significantly reduced the severity of powdery mildew to 15% compared with 100% severity on control plants. Maximum suppression of powdery mildew was observed following 15 min of exposure to UV-B (1.1% severity compared with 100% severity on control plants) but exposure time had to be limited to 5 to 10 min to reduce phytotoxicity. There was no additional disease suppression when plants were exposed to UV-B beginning 2 days prior to inoculation compared with plants exposed to UV-B beginning on the day of inoculation. UV-B inhibited germination, infection, colony expansion, and sporulation of P. xanthii. The results suggest that efficacy of UV-B treatments, alone or in combination with red light, against P. xanthii can be enhanced by exposure of inoculated plants to these wavelengths of radiation during the night, thereby circumventing the counteracting effects of blue light and UV-A radiation. The effect of UV-B on powdery mildew seemed to be directly upon the pathogen, rather than induced resistance of the host. Night exposure of plants to 5 to 10 min of UV-B at 1 W/m2 and inexpensive, spectral-specific, light-emitting diodes may provide additional tools to suppress powdery mildews of diverse greenhouse crops.

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Calcium Positively Mediates Blue Light-Induced Anthocyanin Accumulation in Hypocotyl of Soybean Sprouts

Frontiers in Plant Science ◽

10.3389/fpls.2021.662091 ◽

2021 ◽

Vol 12 ◽

Author(s):

Gang Hu ◽

Xiaomeng Yue ◽

Jinxue Song ◽

Guipei Xing ◽

Jun Chen ◽

...

Keyword(s):

Blue Light ◽

Anthocyanin Biosynthesis ◽

Calcium Supplementation ◽

Distribution Patterns ◽

Anthocyanin Synthesis ◽

Regulation Mechanism ◽

Anthocyanin Content ◽

Anthocyanin Accumulation ◽

Soybean Sprouts ◽

Expression Of Genes

Soybean sprouts are a flavorful microgreen that can be eaten all year round and are widely favored in Southeast Asia. In this study, the regulatory mechanism of calcium on anthocyanin biosynthesis in soybean sprouts under blue light was investigated. The results showed that blue light, with a short wavelength, effectively induced anthocyanin accumulation in the hypocotyl of soybean sprout cultivar “Dongnong 690.” Calcium supplementation further enhanced anthocyanin content, which was obviously inhibited by LaCl3 and neomycin treatment. Moreover, exogenous calcium changed the metabolism of anthocyanins, and seven anthocyanin compounds were detected. The trend of calcium fluorescence intensity in hypocotyl cells, as well as that of the inositol 1,4,5-trisphosphate and calmodulin content, was consistent with that of anthocyanins content. Specific spatial distribution patterns of calcium antimonate precipitation were observed in the ultrastructure of hypocotyl cells under different conditions. Furthermore, calcium application upregulated the expression of genes related to anthocyanin biosynthesis, and calcium inhibitors suppressed these genes. Finally, transcriptomics was performed to gain global insights into the molecular regulation mechanism of calcium-associated anthocyanin production. Genes from the flavonoid biosynthesis pathway were distinctly enriched among the differentially expressed genes, and weighted gene co-expression network analysis showed that two MYBs were related to the accumulation of anthocyanins. These results indicated that calcium released from apoplast and intracellular stores in specific spatial-temporal features promote blue light-induced anthocyanin accumulation by upregulation of the expression of genes related to anthocyanin synthesis of “Dongnong 690” hypocotyl. The findings deepen the understanding of the calcium regulation mechanism of blue light-induced anthocyanin accumulation in soybean sprouts, which will help growers produce high-quality foods beneficial for human health.

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