Effects of White, Blue, and Red Light-Emitting Diodes on Carotenoid Biosynthetic Gene Expression Levels and Carotenoid Accumulation in Sprouts of Tartary Buckwheat (Fagopyrum tataricum Gaertn.)

2013 ◽  
Vol 61 (50) ◽  
pp. 12356-12361 ◽  
Author(s):  
Pham Anh Tuan ◽  
Aye Aye Thwe ◽  
Yeon Bok Kim ◽  
Jae Kwang Kim ◽  
Sun-Ju Kim ◽  
...  
Keyword(s):  
Gene Expression ◽  
Light Emitting Diodes ◽  
Red Light ◽  
Biosynthetic Gene ◽  
Fagopyrum Tataricum ◽  
Light Emitting ◽  
Expression Levels ◽  
Carotenoid Accumulation ◽  
Gene Expression Levels ◽  
Biosynthetic Gene Expression

scholarly journals Antibacterial Mechanism of 405-Nanometer Light-Emitting Diode against Salmonella at Refrigeration Temperature

2016 ◽  
Vol 83 (5) ◽  
Author(s):  
Min-Jeong Kim ◽  
Hyun-Gyun Yuk
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Light Emitting Diode ◽  
Dna Oxidation ◽  
Uptake System ◽  
Antibacterial Mechanism ◽  
Content Type ◽  
Light Emitting ◽  
Expression Levels ◽  
Gene Expression Levels

ABSTRACT The aim of this study was to elucidate the antibacterial mechanism of 405 ± 5-nm light-emitting diode (LED) illumination against Salmonella at 4°C in phosphate-buffered saline (PBS) by determining endogenous coproporphyrin content, DNA oxidation, damage to membrane function, and morphological change. Gene expression levels, including of oxyR, recA, rpoS, sodA, and soxR, were also examined to understand the response of Salmonella to LED illumination. The results showed that Salmonella strains responded differently to LED illumination, revealing that S. enterica serovar Enteritidis (ATCC 13076) and S. enterica subsp. enterica serovar Saintpaul (ATCC 9712) were more susceptible and resistant, respectively, than the 16 other strains tested. There was no difference in the amounts of endogenous coproporphyrin in the two strains. Compared with that in nonilluminated cells, the DNA oxidation levels in illuminated cells increased. In illuminated cells, we observed a loss of efflux pump activity, damage to the glucose uptake system, and changes in membrane potential and integrity. Transmission electron microscopy revealed a disorganization of chromosomes and ribosomes due to LED illumination. The levels of the five genes measured in the nonilluminated and illuminated S. Saintpaul cells were upregulated in PBS at a set temperature of 4°C, indicating that increased gene expression levels might be due to a temperature shift and nutrient deficiency rather than to LED illumination. In contrast, only oxyR in S. Enteritidis cells was upregulated. Thus, different sensitivities of the two strains to LED illumination were attributed to differences in gene regulation. IMPORTANCE Bacterial inactivation using visible light has recently received attention as a safe and environmentally friendly technology, in contrast with UV light, which has detrimental effects on human health and the environment. This study was designed to understand how 405 ± 5-nm light-emitting diode (LED) illumination kills Salmonella strains at refrigeration temperature. The data clearly demonstrated that the effectiveness of LED illumination on Salmonella strains depended highly on the serotype and strain. Our findings also revealed that its antibacterial mechanism was mainly attributed to DNA oxidation and a loss of membrane functions rather than membrane lipid peroxidation, which has been proposed by other researchers who studied the antibacterial effect of LED illumination by adding exogenous photosensitizers, such as chlorophyllin and hypericin. Therefore, this study suggests that the detailed antibacterial mechanisms of 405-nm LED illumination without additional photosensitizers may differ from that by exogenous photosensitizers. Furthermore, a change in stress-related gene regulation may alter the susceptibility of Salmonella cells to LED illumination at refrigeration temperature. Thus, our study provides new insights into the antibacterial mechanism of 405 ± 5-nm LED illumination on Salmonella cells.

scholarly journals Effect of Light-Emitting Diodes and Ultraviolet Irradiation on the Soluble Sugar, Organic Acid, and Carotenoid Content of Postharvest Sweet Oranges (Citrus sinensis (L.) Osbeck)

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3440 ◽  
Author(s):  
Linping Hu ◽  
Can Yang ◽  
Lina Zhang ◽  
Jing Feng ◽  
Wanpeng Xi
Keyword(s):  
Organic Acid ◽  
Citrus Sinensis ◽  
Light Emitting Diodes ◽  
Soluble Sugar ◽  
Red Light ◽  
Carotenoid Content ◽  
Light Emitting ◽  
Total Soluble Sugar ◽  
Carotenoid Accumulation ◽  
Dark Shade

Mature ‘Hamlin’ sweet oranges (Citrus sinensis (L.) Osbeck) were irradiated using light-emitting diodes (LEDs) and ultraviolet (UV) light for six days after harvest. Based on evaluation of the basic ripening parameters of fruits, the contents of soluble sugars, organic acids, and carotenoids were analyzed (in pulps) on the sixth day by high-performance liquid chromatography (HPLC). The results showed that LED and UV irradiation not only accelerated orange ripening but also caused significant changes in the soluble sugar, organic acid, and carotenoid content. Compared with fruit subjected to dark shade (DS) treatment, the total soluble sugar, fructose, and glucose contents increased significantly in UV-treated (UVA, UVB, and UVC) fruits, while the sucrose content increased remarkably in white light, UVB, and UVC-treated fruits (p < 0.05). UV treatment was associated with inducing the largest effect on the total soluble sugar content. Except for UVB, other types of light notably induced an accumulation of the total organic acid content, none but blue light and red light markedly induced citric acid accumulation (p < 0.05). Interestingly, only the red light and dark shade treatments had markedly positive effects in terms of inducing carotenoid accumulation, including the total carotenoid, isolutein, zeaxanthin, lutein, neoxanthin, all-trans-violaxanthin, phytofluene, cis-ζ-carotene, and β-carotene concentrations. Other light treatments had significantly negative effects on carotenoid accumulation (p < 0.05). Therefore, soluble sugar, organic acid, and carotenoid accumulation in sweet oranges vary depending on the levels of UV and LED irradiation. Appropriate light irradiation is a potentially effective way to maintain or improve postharvest fruit quality.

Comparison of carotenoid accumulation and biosynthetic gene expression between Valencia and Rohde Red Valencia sweet oranges

Plant Science ◽  
2014 ◽  
Vol 227 ◽  
pp. 28-36 ◽  
Author(s):  
Xu Wei ◽  
Chunxian Chen ◽  
Qibin Yu ◽  
Antoine Gady ◽  
Yuan Yu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Biosynthetic Gene ◽  
Carotenoid Accumulation ◽  
Biosynthetic Gene Expression

scholarly journals Understanding the luminescent nature of organic radicals for efficient doublet emitters and pure-red light-emitting diodes

2020 ◽  
Vol 19 (11) ◽  
pp. 1224-1229 ◽  
Author(s):  
Alim Abdurahman ◽  
Timothy J. H. Hele ◽  
Qinying Gu ◽  
Jiangbin Zhang ◽  
Qiming Peng ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Red Light ◽  
Organic Radicals ◽  
Light Emitting
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