The quality of light is an important abiotic factor that affects the growth and development of photosynthetic organisms.In this study,we exposed the unicellular green alga Dunaliella salina to red(660 nm)and blue(450 ...The quality of light is an important abiotic factor that affects the growth and development of photosynthetic organisms.In this study,we exposed the unicellular green alga Dunaliella salina to red(660 nm)and blue(450 nm)light and analyzed the cell growth,total carotenoid content,and transcriptomes.The growth of D.salina was enhanced by illumination with red light,whereas blue light was not able to promote the algal growth.In contrast,the total carotenoid content increased under both red and blue light.The RNA of D.salina was sequenced and the transcriptomic response of algal cells to red and blue light was investigated.Six transcripts encoding for the blue light receptor cryptochrome were identified,and transcripts involved in the carotenoid metabolism were up-regulated under both red and blue light.Transcripts encoding for photoprotective enzymes related to the scavenging of reactive oxygen species were up-regulated under blue light.The present transcriptomic study provides a more comprehensive understanding of carotenoid biosynthesis in D.salina under different wavelengths of light.展开更多
Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato ...Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato production.However,few studies have documented the effects of red and blue light on the growth of potato plantlets revealed at the transcriptome level.The objective of this study was to determine the growth and physiological responses of potato plantlets cultured in vitro under monochromatic red(RR),monochromatic blue(BB)as well as combined red and blue(RB)LEDs using the RNA-Seq technique.In total,3150 and 814 differentially expressed genes(DEGs)were detected in potato plantlets under RR and BB,respectively,compared to RB(used as control).Compared to the control,the DEGs enriched in"photosynthesis"and"photosynthesis-antenna proteins"metabolic pathways were up-regulated and down-regulated by BB and RR,respectively,which might be responsible for the increases and decreases of maximum quantum yield(F_(v)/F_(m)),photochemical quantum yield(φ_(PSII)),photochemical quenching(q_(P))and electron transfer rate(ETR)in BB and RR,respectively.Potato plantlets exhibited dwarfed stems and extended leaves under BB,whereas elongated stems and small leaves were induced under RR.These dramatically altered plantlet phenotypes were associated with variable levels of endogenous plant hormones gibberellin(GAs),indoleacetic acid(IAA)and cytokinins(CKs),as assessed in stems and leaves of potato plantlets.In addition,monochromatic red and blue LEDs trigged the opposite expression profiles of DEGs identified in the"plant hormone signal transduction"metabolic pathway,which were closely related to the endogenous plant hormone levels in potato plantlets.Our results provide insights into the responses of potato plantlets cultured in vitro to red and blue LEDs at the transcriptomic level and may contribute to improvements in the micro-propagation of potato plantlets cultured in vitro from the light spectrum aspect.展开更多
Blue and red light are spectral wavelengths more effective for plants. The effects of different ratios of red and blue light (R/B=2, R/B=4, R/B=8, R/B=12) provided by LEDs on morphology and photosynthetic characteri...Blue and red light are spectral wavelengths more effective for plants. The effects of different ratios of red and blue light (R/B=2, R/B=4, R/B=8, R/B=12) provided by LEDs on morphology and photosynthetic characteristics of tomato seedlings were studied. The results showed that plant height, stem diameter, fresh weight, dry weight, seedling index and G value increased with the increase of R/B ratio until 8. On the contrary, SPDA value decreased with the increase of R/B ratio. Photosynthetic characteristics were measured by CO 2 assimilation ( Pn ), stomatal conductance ( gs ) and intracellular CO 2 concentration ( Ci) . Pn and gs decreased with the increase of R/B ratio. Furthermore, similar trend was investigated in photochemical quenching (qP) and electron transport rate (ETR). Results of this study suggest that compared with white LED, appropriate combination of red and blue light can enhance plant growth and photosynthetic characteristics, and the optimal blue/red ratio for tomato growth was R/B=8.展开更多
Lycopene, one of the strongest natural antioxidants known and the main carotene in ripe tomato, is very important for human health. Light is well known to be one of the most important environmental stimuli influencing...Lycopene, one of the strongest natural antioxidants known and the main carotene in ripe tomato, is very important for human health. Light is well known to be one of the most important environmental stimuli influencing lycopene biosynthesis; specifically, red light induces higher lycopene content in tomato. However, whether blue light promotes lycopene synthesis remains elusive and exactly how light stimulation promotes lycopene synthesis remains unclear. We applied supplemental blue and red lighting on tomato plants at anthesis to monitor the effect of supplemental blue and red lighting on lycopene synthesis. Our results showed that supplemental blue/red lighting induced higher lycopene content in tomato fruits; furthermore, we found that the expression of key genes in the lycopene synthesis pathway was induced by supplemented blue/red light. The expression of light signaling components, such as red-light receptor phytochromes(PHYs), blue-light receptor cryptochromes(CRYs) and light interaction factors, phytochrome-interacting factors(PIFs) and ELONGATED HYPOCOTYL 5(HY5) were up-or down-regulated by blue/red lighting. Thus, blue and red light increased lycopene content in tomatoes by inducing light receptors that modulate HY5 and PIFs activation to mediate phytoene synthase 1(PSY1) gene expression. These results provide a sound theoretical basis for further elucidation of the light regulating mechanism of lycopene synthesis in tomatoes, and for instituting a new generation of technological innovations for the enhancement of lycopene accumulation in crop production.展开更多
The photosynthetic characteristics of strawberry (Fragariaananassa Duch. cv. Toyonoka)leaves under illumination of identical light intensity(55-57% natural light) withdifferent light quality were studied. It was showe...The photosynthetic characteristics of strawberry (Fragariaananassa Duch. cv. Toyonoka)leaves under illumination of identical light intensity(55-57% natural light) withdifferent light quality were studied. It was showed that the chlorophyll content,maximal photochemical efficiency of PSⅡ(Fv/Fm), Fm/Fo, amount of inactive PSⅡreactioncenters (Fi-Fo) and rate of QA reduction were positively correlated with the red-light/blue-light ratios, but the chlorophyll (a/b) ratios were negatively correlated withthem. Carotenoid content of the leaves was maximum under the blue film, than under greenfilm, red film, white film and yellow film, and negatively correlated with the red/far-red ratios. The apparent quantum yield (AQY), photorespiratory rate (Pr) and carboxylationefficiency (CE) were also strongly affected by light quality. The photosynthetic rate(Pn) in strawberry leaves under green film was significantly lower than under all otherfilm. Our results suggested that light quality is an essential factor regulating thedevelopment of PSⅡ, and phytochrome and an independent blue light photoreceptor,possibly a cryptochrome, can regulate photosynthetic performance.展开更多
We evaluated the effects of red and blue light on the repair of UV-B radiation-induced damage in tetraspores of Chondrus ocellatus Holm. Tetraspores of C. ocellatus were treated with different UV-B radiation levels(0,...We evaluated the effects of red and blue light on the repair of UV-B radiation-induced damage in tetraspores of Chondrus ocellatus Holm. Tetraspores of C. ocellatus were treated with different UV-B radiation levels(0,36,72,108,144 and 180 J/m2),and thereafter subjected to PAR,darkness,or red or blue light during a 2-h repair stage,each day for 48 days. The diameters and cellular contents of cyclobutane pyrimidine dimmers(CPDs),chlorophyll a(Chl a),phycoerythrin,and UV-B-absorbing mycosporinelike amino acids(MAAs) contents of the tetraspores were determined. Our results show that low doses of UV-B radiation(36 and 72 J/m 2) promoted the growth of C. ocellatus; however,increased UV-B radiation gradually reduced the C. ocellatus growth(greater than 72 J/m2). The MAAs(palythine and asterina-330) in C. ocellatus were detected and analyzed by LC/MS. Our results suggest that moderate red light could induce the growth of this alga in aquaculture. In addition,photorepair was inhibited by red light,so there may be some other DNA repair mechanism activated by red light. Blue light promoted the activity of DNA photolyase,greatly improving remediation efficiency. Red and blue lights were found to reduce the capacity of C. ocellatus to form MAAs. Therefore,PAR,red light,and blue light play different roles during the repair processes for damage induced by UV-B radiation.展开更多
In plant cultivation, the number of photons is more important than the light energy from the chemical reactions that occur during photosynthesis. In addition, the blue and red photon flux (B/R) ratio is an important p...In plant cultivation, the number of photons is more important than the light energy from the chemical reactions that occur during photosynthesis. In addition, the blue and red photon flux (B/R) ratio is an important parameter for plant cultivation. Here we discuss the effect of the spectral irradiance distribution and the B/R ratio on plant cultivation. We cultivated lettuce seedlings, Lactuca sativa L. Cv. Okayama, using a light-emitting diode illumination system that can precisely control the spectral irradiance distribution and B/R ratio. The B/R ratio varied from 0.36 to 2.06 according to the intensity of the blue light when the photosynthetic photon flux density values were sufficient to ensure the 150 - 200?μmol⋅m−2⋅s−1.?High photon flux densities of blue light result in reduced plant length, plant height, and leaf area, thereby suggesting its role in the suppression of leaf growth. Therefore, we conclude that a lower photon flux of blue light (B/R Ratio) is optimal for lettuce cultivation.展开更多
Optoelectronic applications require the development of new fluorescent and efficient luminescent materials, free of toxicity, low in cost, and easy to produce. In this way the synthesis of zinc-oxide (ZnO) quantum dot...Optoelectronic applications require the development of new fluorescent and efficient luminescent materials, free of toxicity, low in cost, and easy to produce. In this way the synthesis of zinc-oxide (ZnO) quantum dots (QDs) has recently received special attention due to their good optical, electrical and chemical properties with low production costs and blue light emission. In this work ZnO QDs were successfully doped with europium in order to obtain a tunable emission luminescence from blue emission of ZnO to red emission of europium as a function of wavelength excitation. Results show an efficient blue to red tuning when the excitation wavelength was changed from 317 nm to 395 nm, respectively. This opens the possibility of having new optical devices to produce different color emission using the same material.展开更多
Light quality significantly affects photosynthetic efficiency in plants. The mechanisms for how light quality affects photosynthesis in grape is poorly understood. Therefore, to investigate the effects of different li...Light quality significantly affects photosynthetic efficiency in plants. The mechanisms for how light quality affects photosynthesis in grape is poorly understood. Therefore, to investigate the effects of different light qualities on chloroplast ultrastructure and photosynthesis efficiency, two grape cultivars ‘Italia'(slower speed of leaf senescence) and ‘Centennial Seedless'(faster speed of leaf senescence) grown under protected and delayed conditions were used. The three treatments, replicated three times, were control(no supplemental lighting), red light and blue light. Chlorophyll content, net photosynthetic rate, and the ratio of F_v/F_m significantly increased in red light relative to the control. The opposite trend was observed in blue light in the early phase of leaf senescence. At later stages, physiological indexes were gradually higher than that of control, resulting in a delay in leaf senescence. Compared to the control, red and blue light both significantly increased the chlorophyll a/b ratio. Electron microscopy showed that blue light caused severe damage to the fine structure of chloroplasts at early stages of leaf senescence, but effects at later stages of leaf senescence became less severe compared to the control. The degradation of chloroplast ultrastructure was apparently delayed in red light throughout the experimental timeframe compared to other treatments. In this experiment, ‘Italia' showed higher chlorophyll content, net photosynthetic rate, ratios of F_v/F_m, chlorophyll a/b and better preserved chloroplast ultrastructure relative to ‘Centennial Seedless', resulting in a slower rate of leaf senescence.展开更多
We evaluated the effects of ultraviolet-B (UV-B) radiation and different light conditions on the repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm (Rhodophyta) in laboratory experiments. Carp...We evaluated the effects of ultraviolet-B (UV-B) radiation and different light conditions on the repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm (Rhodophyta) in laboratory experiments. Carpospores were treated daily with different doses of UV-B radiation for 48 days, when vertical branches had formed in all treatments; after each daily treatment, the carpospores were subjected to photosynthetically active radiation (PAR), darkness, red light, or blue light during a 2-h repair stage. Carpospore diameters were measured every 4 days. We measured the growth and cellular contents of cyclobutane pyrimidine dimers (CPDs), chlorophyll a, phycoerythrin, and UV-B-absorbing mycosporine-like amino acids (MAAs) in carpospores on Day 48. Low doses of UV-B radiation (36 and 72 J/m2) accelerated the growth of C. ocellatus. However, as the amount of UV-B radiation increased, the growth rate decreased and morphological changes occurred. UV-B radiation significant damaged DNA and photosynthetic pigments and induced three kind of MAAs, palythine, asterina-330, and shinorine. PAR conditions were best for repairing UV-B-induced damage. Darkness promoted the activity of the DNA dark- repair mechanism. Red light enhanced phycoerythrin synthesis but inhibited light repair of DNA. Although blue light, increased the activity of DNA photolyase, greatly improving remediation efficiency, the growth and development of C. ocellatus earpospores were slower than in other light treatments.展开更多
目的评价红蓝光联合治疗慢性伤口的效果。方法检索PubMed、Embase、Web of Science、Cochrane Library、中国知网、万方、维普、中国生物医学文献数据库(CBM)中关于红蓝光联合辅助慢性伤口治疗的文献,检索时限为2012年1月至2022年7月。...目的评价红蓝光联合治疗慢性伤口的效果。方法检索PubMed、Embase、Web of Science、Cochrane Library、中国知网、万方、维普、中国生物医学文献数据库(CBM)中关于红蓝光联合辅助慢性伤口治疗的文献,检索时限为2012年1月至2022年7月。由2名研究者独立进行文献筛选、资料提取和质量评价,采用RevMan 5.4软件进行统计分析。结果共纳入10篇文献,累计样本量为710例,Meta分析结果显示:观察组伤口痊愈率高于对照组[OR=2.03,95%CI(1.33~3.11),P=0.001],肉芽组织分级高于对照组[MD=0.95,95%CI(0.18,1.73),P=0.02],创面面积缩小率高于对照组[MD=14.43,95%CI(10.98~17.87),P<0.001],伤口愈合时间低于对照组[MD=-7.16,95%CI(-8.56~-5.74),P<0.001],换药次数低于对照组[MD=-5.44,95%CI(-5.94~-4.95),P<0.001],观察组与对照组伤口附近皮肤评分差异无统计学意义[MD=0.10,95%CI(-0.93~1.12),P=0.85]。结论红蓝光联合使用治疗慢性伤口能有效提高伤口痊愈率、肉芽组织分级及创面面积缩小率,同时能缩短伤口愈合时间,减少换药次,且对伤口附近皮肤无影响。展开更多
In order to flower in the appropriate season,plants monitor light and temperature changes and alter downstream pathways that regulate florigen genes such as Arabidopsis(Arabidopsis thaliana)FLOWERING LOCUS T(FT).In Ar...In order to flower in the appropriate season,plants monitor light and temperature changes and alter downstream pathways that regulate florigen genes such as Arabidopsis(Arabidopsis thaliana)FLOWERING LOCUS T(FT).In Arabidopsis,FT messenger RNA levels peak in the morning and evening under natural long-day conditions(LDs).However,the regulatory mechanisms governing morning FT induction remain poorly understood.The morning FT peak is absent in typical laboratory LDs characterized by high red:far-red light(R:FR)ratios and constant temperatures.Here,we demonstrate that ZEITLUPE(ZTL)interacts with the FT repressors TARGET OF EATs(TOEs),thereby repressing morning FT expression in natural environments.Under LDs with simulated sunlight(R:FR=1.0)and daily temperature cycles,which are natural LD-mimicking environmental conditions,FT transcript levels in the ztl mutant were high specifically in the morning,a pattern that was mirrored in the toe1 toe2 double mutant.Low night-to-morning temperatures increased the inhibitory effect of ZTL on morning FT expression by increasing ZTL protein levels early in the morning.Far-red light counteracted ZTL activity by decreasing its abundance(possibly via phytochrome A(phyA))while increasing GIGANTEA(GI)levels and negatively affecting the formation of the ZTL-GI complex in the morning.Therefore,the phyA-mediated high-irradiance response and GI play pivotal roles in morning FT induction.Our findings suggest that the delicate balance between low temperature-mediated ZTL activity and the far-red light-mediated functions of phyA and GI offers plants flexibility in fine-tuning their flowering time by controlling FT expression in the morning.展开更多
基金Supported by the National Natural Science Foundation of China(No.41506188)the China Nantong Municipal Applied Basic Research Program(No.MS12017025-2)the Tianjin Demonstration Project for Innovative Development of Marine Economy(No.BHSF2017-21)
文摘The quality of light is an important abiotic factor that affects the growth and development of photosynthetic organisms.In this study,we exposed the unicellular green alga Dunaliella salina to red(660 nm)and blue(450 nm)light and analyzed the cell growth,total carotenoid content,and transcriptomes.The growth of D.salina was enhanced by illumination with red light,whereas blue light was not able to promote the algal growth.In contrast,the total carotenoid content increased under both red and blue light.The RNA of D.salina was sequenced and the transcriptomic response of algal cells to red and blue light was investigated.Six transcripts encoding for the blue light receptor cryptochrome were identified,and transcripts involved in the carotenoid metabolism were up-regulated under both red and blue light.Transcripts encoding for photoprotective enzymes related to the scavenging of reactive oxygen species were up-regulated under blue light.The present transcriptomic study provides a more comprehensive understanding of carotenoid biosynthesis in D.salina under different wavelengths of light.
基金funded by the Scientific Research Fund of College of Science&Technology,Ningbo University for the Introduction of High-level Talents,China(RC190006)。
文摘Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato production.However,few studies have documented the effects of red and blue light on the growth of potato plantlets revealed at the transcriptome level.The objective of this study was to determine the growth and physiological responses of potato plantlets cultured in vitro under monochromatic red(RR),monochromatic blue(BB)as well as combined red and blue(RB)LEDs using the RNA-Seq technique.In total,3150 and 814 differentially expressed genes(DEGs)were detected in potato plantlets under RR and BB,respectively,compared to RB(used as control).Compared to the control,the DEGs enriched in"photosynthesis"and"photosynthesis-antenna proteins"metabolic pathways were up-regulated and down-regulated by BB and RR,respectively,which might be responsible for the increases and decreases of maximum quantum yield(F_(v)/F_(m)),photochemical quantum yield(φ_(PSII)),photochemical quenching(q_(P))and electron transfer rate(ETR)in BB and RR,respectively.Potato plantlets exhibited dwarfed stems and extended leaves under BB,whereas elongated stems and small leaves were induced under RR.These dramatically altered plantlet phenotypes were associated with variable levels of endogenous plant hormones gibberellin(GAs),indoleacetic acid(IAA)and cytokinins(CKs),as assessed in stems and leaves of potato plantlets.In addition,monochromatic red and blue LEDs trigged the opposite expression profiles of DEGs identified in the"plant hormone signal transduction"metabolic pathway,which were closely related to the endogenous plant hormone levels in potato plantlets.Our results provide insights into the responses of potato plantlets cultured in vitro to red and blue LEDs at the transcriptomic level and may contribute to improvements in the micro-propagation of potato plantlets cultured in vitro from the light spectrum aspect.
基金Supported by Shanghai Science and Technology Commission Project,China(14DZ1206303)National Key Technology R&D Program(2014BAD05B05-05)Shanghai Agriculture Applied Technology Development Program,China(Grant No.20170201)
文摘Blue and red light are spectral wavelengths more effective for plants. The effects of different ratios of red and blue light (R/B=2, R/B=4, R/B=8, R/B=12) provided by LEDs on morphology and photosynthetic characteristics of tomato seedlings were studied. The results showed that plant height, stem diameter, fresh weight, dry weight, seedling index and G value increased with the increase of R/B ratio until 8. On the contrary, SPDA value decreased with the increase of R/B ratio. Photosynthetic characteristics were measured by CO 2 assimilation ( Pn ), stomatal conductance ( gs ) and intracellular CO 2 concentration ( Ci) . Pn and gs decreased with the increase of R/B ratio. Furthermore, similar trend was investigated in photochemical quenching (qP) and electron transport rate (ETR). Results of this study suggest that compared with white LED, appropriate combination of red and blue light can enhance plant growth and photosynthetic characteristics, and the optimal blue/red ratio for tomato growth was R/B=8.
基金supported by the National Key Research and Development Program of China (2017YFD0701500)the Teamwork Projects Funded by Guangdong Natural Science Foundation, China (S2013030012842)the Guangzhou Science & Technology Project, China (201704020058)
文摘Lycopene, one of the strongest natural antioxidants known and the main carotene in ripe tomato, is very important for human health. Light is well known to be one of the most important environmental stimuli influencing lycopene biosynthesis; specifically, red light induces higher lycopene content in tomato. However, whether blue light promotes lycopene synthesis remains elusive and exactly how light stimulation promotes lycopene synthesis remains unclear. We applied supplemental blue and red lighting on tomato plants at anthesis to monitor the effect of supplemental blue and red lighting on lycopene synthesis. Our results showed that supplemental blue/red lighting induced higher lycopene content in tomato fruits; furthermore, we found that the expression of key genes in the lycopene synthesis pathway was induced by supplemented blue/red light. The expression of light signaling components, such as red-light receptor phytochromes(PHYs), blue-light receptor cryptochromes(CRYs) and light interaction factors, phytochrome-interacting factors(PIFs) and ELONGATED HYPOCOTYL 5(HY5) were up-or down-regulated by blue/red lighting. Thus, blue and red light increased lycopene content in tomatoes by inducing light receptors that modulate HY5 and PIFs activation to mediate phytoene synthase 1(PSY1) gene expression. These results provide a sound theoretical basis for further elucidation of the light regulating mechanism of lycopene synthesis in tomatoes, and for instituting a new generation of technological innovations for the enhancement of lycopene accumulation in crop production.
基金supported by the National Natura1 Science Foundation of China(39730340)
文摘The photosynthetic characteristics of strawberry (Fragariaananassa Duch. cv. Toyonoka)leaves under illumination of identical light intensity(55-57% natural light) withdifferent light quality were studied. It was showed that the chlorophyll content,maximal photochemical efficiency of PSⅡ(Fv/Fm), Fm/Fo, amount of inactive PSⅡreactioncenters (Fi-Fo) and rate of QA reduction were positively correlated with the red-light/blue-light ratios, but the chlorophyll (a/b) ratios were negatively correlated withthem. Carotenoid content of the leaves was maximum under the blue film, than under greenfilm, red film, white film and yellow film, and negatively correlated with the red/far-red ratios. The apparent quantum yield (AQY), photorespiratory rate (Pr) and carboxylationefficiency (CE) were also strongly affected by light quality. The photosynthetic rate(Pn) in strawberry leaves under green film was significantly lower than under all otherfilm. Our results suggested that light quality is an essential factor regulating thedevelopment of PSⅡ, and phytochrome and an independent blue light photoreceptor,possibly a cryptochrome, can regulate photosynthetic performance.
基金Supported by the Program for New Century Excellent Talents in University(No.NCET-05-0597)the National Natural Science Foundation of China(No.30270258)
文摘We evaluated the effects of red and blue light on the repair of UV-B radiation-induced damage in tetraspores of Chondrus ocellatus Holm. Tetraspores of C. ocellatus were treated with different UV-B radiation levels(0,36,72,108,144 and 180 J/m2),and thereafter subjected to PAR,darkness,or red or blue light during a 2-h repair stage,each day for 48 days. The diameters and cellular contents of cyclobutane pyrimidine dimmers(CPDs),chlorophyll a(Chl a),phycoerythrin,and UV-B-absorbing mycosporinelike amino acids(MAAs) contents of the tetraspores were determined. Our results show that low doses of UV-B radiation(36 and 72 J/m 2) promoted the growth of C. ocellatus; however,increased UV-B radiation gradually reduced the C. ocellatus growth(greater than 72 J/m2). The MAAs(palythine and asterina-330) in C. ocellatus were detected and analyzed by LC/MS. Our results suggest that moderate red light could induce the growth of this alga in aquaculture. In addition,photorepair was inhibited by red light,so there may be some other DNA repair mechanism activated by red light. Blue light promoted the activity of DNA photolyase,greatly improving remediation efficiency. Red and blue lights were found to reduce the capacity of C. ocellatus to form MAAs. Therefore,PAR,red light,and blue light play different roles during the repair processes for damage induced by UV-B radiation.
文摘In plant cultivation, the number of photons is more important than the light energy from the chemical reactions that occur during photosynthesis. In addition, the blue and red photon flux (B/R) ratio is an important parameter for plant cultivation. Here we discuss the effect of the spectral irradiance distribution and the B/R ratio on plant cultivation. We cultivated lettuce seedlings, Lactuca sativa L. Cv. Okayama, using a light-emitting diode illumination system that can precisely control the spectral irradiance distribution and B/R ratio. The B/R ratio varied from 0.36 to 2.06 according to the intensity of the blue light when the photosynthetic photon flux density values were sufficient to ensure the 150 - 200?μmol⋅m−2⋅s−1.?High photon flux densities of blue light result in reduced plant length, plant height, and leaf area, thereby suggesting its role in the suppression of leaf growth. Therefore, we conclude that a lower photon flux of blue light (B/R Ratio) is optimal for lettuce cultivation.
文摘Optoelectronic applications require the development of new fluorescent and efficient luminescent materials, free of toxicity, low in cost, and easy to produce. In this way the synthesis of zinc-oxide (ZnO) quantum dots (QDs) has recently received special attention due to their good optical, electrical and chemical properties with low production costs and blue light emission. In this work ZnO QDs were successfully doped with europium in order to obtain a tunable emission luminescence from blue emission of ZnO to red emission of europium as a function of wavelength excitation. Results show an efficient blue to red tuning when the excitation wavelength was changed from 317 nm to 395 nm, respectively. This opens the possibility of having new optical devices to produce different color emission using the same material.
基金supported by the grants from National Natural Science Foundation of China(No.41101573)China Agriculture Research System(nycytx-30-zp)CAAS-ASTIP-2015-RIP-04
文摘Light quality significantly affects photosynthetic efficiency in plants. The mechanisms for how light quality affects photosynthesis in grape is poorly understood. Therefore, to investigate the effects of different light qualities on chloroplast ultrastructure and photosynthesis efficiency, two grape cultivars ‘Italia'(slower speed of leaf senescence) and ‘Centennial Seedless'(faster speed of leaf senescence) grown under protected and delayed conditions were used. The three treatments, replicated three times, were control(no supplemental lighting), red light and blue light. Chlorophyll content, net photosynthetic rate, and the ratio of F_v/F_m significantly increased in red light relative to the control. The opposite trend was observed in blue light in the early phase of leaf senescence. At later stages, physiological indexes were gradually higher than that of control, resulting in a delay in leaf senescence. Compared to the control, red and blue light both significantly increased the chlorophyll a/b ratio. Electron microscopy showed that blue light caused severe damage to the fine structure of chloroplasts at early stages of leaf senescence, but effects at later stages of leaf senescence became less severe compared to the control. The degradation of chloroplast ultrastructure was apparently delayed in red light throughout the experimental timeframe compared to other treatments. In this experiment, ‘Italia' showed higher chlorophyll content, net photosynthetic rate, ratios of F_v/F_m, chlorophyll a/b and better preserved chloroplast ultrastructure relative to ‘Centennial Seedless', resulting in a slower rate of leaf senescence.
基金Supported by the Program for New Century Excellent Talents in University(No.NCET-05-0597)the National Natural Science Foundation of China(No.30270258)
文摘We evaluated the effects of ultraviolet-B (UV-B) radiation and different light conditions on the repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm (Rhodophyta) in laboratory experiments. Carpospores were treated daily with different doses of UV-B radiation for 48 days, when vertical branches had formed in all treatments; after each daily treatment, the carpospores were subjected to photosynthetically active radiation (PAR), darkness, red light, or blue light during a 2-h repair stage. Carpospore diameters were measured every 4 days. We measured the growth and cellular contents of cyclobutane pyrimidine dimers (CPDs), chlorophyll a, phycoerythrin, and UV-B-absorbing mycosporine-like amino acids (MAAs) in carpospores on Day 48. Low doses of UV-B radiation (36 and 72 J/m2) accelerated the growth of C. ocellatus. However, as the amount of UV-B radiation increased, the growth rate decreased and morphological changes occurred. UV-B radiation significant damaged DNA and photosynthetic pigments and induced three kind of MAAs, palythine, asterina-330, and shinorine. PAR conditions were best for repairing UV-B-induced damage. Darkness promoted the activity of the DNA dark- repair mechanism. Red light enhanced phycoerythrin synthesis but inhibited light repair of DNA. Although blue light, increased the activity of DNA photolyase, greatly improving remediation efficiency, the growth and development of C. ocellatus earpospores were slower than in other light treatments.
文摘目的评价红蓝光联合治疗慢性伤口的效果。方法检索PubMed、Embase、Web of Science、Cochrane Library、中国知网、万方、维普、中国生物医学文献数据库(CBM)中关于红蓝光联合辅助慢性伤口治疗的文献,检索时限为2012年1月至2022年7月。由2名研究者独立进行文献筛选、资料提取和质量评价,采用RevMan 5.4软件进行统计分析。结果共纳入10篇文献,累计样本量为710例,Meta分析结果显示:观察组伤口痊愈率高于对照组[OR=2.03,95%CI(1.33~3.11),P=0.001],肉芽组织分级高于对照组[MD=0.95,95%CI(0.18,1.73),P=0.02],创面面积缩小率高于对照组[MD=14.43,95%CI(10.98~17.87),P<0.001],伤口愈合时间低于对照组[MD=-7.16,95%CI(-8.56~-5.74),P<0.001],换药次数低于对照组[MD=-5.44,95%CI(-5.94~-4.95),P<0.001],观察组与对照组伤口附近皮肤评分差异无统计学意义[MD=0.10,95%CI(-0.93~1.12),P=0.85]。结论红蓝光联合使用治疗慢性伤口能有效提高伤口痊愈率、肉芽组织分级及创面面积缩小率,同时能缩短伤口愈合时间,减少换药次,且对伤口附近皮肤无影响。
基金supported by the Japan Society for the Promotion of Science(JSPS)KAKENHI grant(No.19K16170 and No.23K05817 to A.K.)National Institutes of Health(NIH)(No.R01GM079712 to T.I.)the National Research Foundation(NRF)of Korea grant funded by the Korean Government(MSIT)(No.NRF-2020R1A2C1014655 andNo.NRF-2021R1A4A1032888 to Y.H.S.).
文摘In order to flower in the appropriate season,plants monitor light and temperature changes and alter downstream pathways that regulate florigen genes such as Arabidopsis(Arabidopsis thaliana)FLOWERING LOCUS T(FT).In Arabidopsis,FT messenger RNA levels peak in the morning and evening under natural long-day conditions(LDs).However,the regulatory mechanisms governing morning FT induction remain poorly understood.The morning FT peak is absent in typical laboratory LDs characterized by high red:far-red light(R:FR)ratios and constant temperatures.Here,we demonstrate that ZEITLUPE(ZTL)interacts with the FT repressors TARGET OF EATs(TOEs),thereby repressing morning FT expression in natural environments.Under LDs with simulated sunlight(R:FR=1.0)and daily temperature cycles,which are natural LD-mimicking environmental conditions,FT transcript levels in the ztl mutant were high specifically in the morning,a pattern that was mirrored in the toe1 toe2 double mutant.Low night-to-morning temperatures increased the inhibitory effect of ZTL on morning FT expression by increasing ZTL protein levels early in the morning.Far-red light counteracted ZTL activity by decreasing its abundance(possibly via phytochrome A(phyA))while increasing GIGANTEA(GI)levels and negatively affecting the formation of the ZTL-GI complex in the morning.Therefore,the phyA-mediated high-irradiance response and GI play pivotal roles in morning FT induction.Our findings suggest that the delicate balance between low temperature-mediated ZTL activity and the far-red light-mediated functions of phyA and GI offers plants flexibility in fine-tuning their flowering time by controlling FT expression in the morning.