Transcriptome analysis of carotenoid biosynthesis in Dunaliella salina under red and blue light

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.

Transcriptome analysis reveals effects of red and blue lightemitting diodes(LEDs)on the growth,chlorophyll fluorescence and endogenous plant hormones of potato(Solanum tuberosum L.)plantlets cultured in vitro

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.

Effects of Different Combinations of Red and Blue Light on Morphology and Photosynthetic Characteristic of Tomato Seedlings

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.

Supplemental blue and red light promote lycopene synthesis in tomato fruits

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.

Effect of Light Quality on Photosynthesis and Chlorophyll Fluorescence in Strawberry Leaves

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.

Effects of UV-B radiation on tetraspores of Chondrus ocellatus Holm(Rhodophyta),and effects of red and blue light on repair of UV-B-induced damage

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.

Study of Plant Cultivation Using a Light-Emitting Diode Illumination System to Control the Spectral Irradiance Distribution

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.

Blue-Red Tuning Emission of ZnO: Europium Quantum Dots with Different Excitation Wavelengths

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.

Red and Blue Lights Significantly Affect Photosynthetic Properties and Ultrastructure of Mesophyll Cells in Senescing Grape Leaves

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.

Effects of different light conditions on repair of UV-B-induced damage in carpospores of Chondrus ocellatus Holm

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.

光质对银杏苗木生长及黄酮类化合物积累的影响

【目的】探究红、蓝光质对银杏苗木生长及黄酮类化合物积累的影响。【方法】以1年生银杏苗为材料,设置红光、蓝光、红蓝混光3种光质,并以白光作为对照(CK),在处理的第3、6、9、12周分别测定银杏苗的黄酮含量及单株产量、黄酮合成相关酶活性和黄酮总还原力,并在第12周测定其生长指标。【结果】光质处理下,银杏苗木的总生物量均低于CK,苗高在蓝光处理下显著提高,地径受光质影响较小。黄酮合成相关酶中,苯丙氨酸解氨酶(PAL)和肉桂酸4-羟化酶(C4H)的活性在混光和蓝光处理下提高,而4-香豆酸辅酶A连接酶(4CL)活性仅在红光处理下提高。光质极显著影响黄酮类化合物(槲皮素、山柰酚、异鼠李素、总黄酮)含量、单株黄酮产量及黄酮提取液总还原力,各处理黄酮产量及总还原力均表现为蓝光和混光强于红光和CK,即蓝光和混光有利于黄酮类化合物的积累及抗氧化能力的提高。随着光质处理时间的延长,黄酮类化合物含量的变化趋势总体表现为前期(第3~6周)高于后期(第9~12周),普遍在第6周达到最大值。【结论】混光和蓝光处理可促进银杏苗木黄酮类化合物的积累及相关酶活性,红光则相反;叶用银杏光质处理时间以6周较为适宜。

不同波长LEDs光源对苦荞芽菜生长、生物活性物积累及抗氧化活性的影响

为探究不同波长LEDs光源对苦荞芽菜生长的影响,本研究以黑暗(D)作对照,采用单色红(R)、蓝(B)、绿(G)光源培养苦荞芽菜,收获后分别测定其形态指标、生物活性物积累量、类黄酮合成关键基因表达量及抗氧化活性指标,结果表明:B处理的苦荞芽菜下胚轴呈深红色,伸长生长受到强烈抑制,花青素、总黄酮及总酚积累量均最高,分别是D的7.18、2.96和2.49倍;R处理的下胚轴呈浅粉色,上述3种生物活性物积累量分别是对照的2.56、1.68和1.40倍;G处理的下胚轴伸长与R相似,外观呈透明白色,生物活性物积累量与对照无显著差异。B和R均强烈诱导类黄酮生物合成通路上关键结构基因表达,显著增加苦荞芽菜下胚轴抗氧化活性。此外,各单色光处理均未显著影响苦荞芽菜可食用部位的鲜重。由此可见,红、蓝LEDs光源可显著影响苦荞芽菜形态生长,并增加其生物活性物积累及抗氧化能力,以蓝光最佳。

红光、蓝光处理下马铃薯转录组特异表达基因密码子的偏好性分析

以红光、蓝光处理下的马铃薯转录组数据为基础,以白光为对照,各筛选出1206条、691条特异表达基因。通过CodonW、CUSP对筛选出的基因编码序列(CDS)进行密码子使用偏好性分析。结果表明,在红光、蓝光处理下,马铃薯对基因密码子的使用偏好性都较弱,都偏好使用A或T(U)结尾的密码子。在2种光质处理下,特异表达基因序列密码子的GC总量都与同义密码子在第3位的胞嘧啶和鸟嘌呤含量(GC3s)有极显著相关性。在2种光质处理下,高频密码子[相对同义密码子使用度(RSCU)>1.00]均为30个,且高频密码子类型完全一致。从ENc-plot、PR2-plot和中性绘图结果可以看出,2种光质处理下的特异表达基因主要受到自然选择的影响。本研究还分别从蓝光、红光处理的特异表达基因中筛选26个、28个最优密码子。从马铃薯在不同光质处理下特异表达基因与其他生物密码子使用频率的比值及聚类分析结果可以看出,番茄、烟草均可作为红光、蓝光处理下马铃薯特异表达基因的异源表达受体。

铈红与钴蓝对聚乙烯棚膜红/蓝光质调控及性能影响

红/蓝光质调控聚乙烯(PE)棚膜一直以来是农膜行业亟需解决的难题。在PE中引入铈红(CeS)和钴蓝(CoO·Al_(2)O_(3)),通过吹塑工艺制备PE红/蓝光棚膜。光电雾度仪测试结果发现CeS和CoO·Al_(2)O_(3)对PE棚膜的透光率影响较小,但雾度和散光度有所增加;光纤光谱仪和手持式光谱照度仪表征结果显示CeS和CoO·Al_(2)O_(3)明显提升450~520 nm的蓝光和605~700 nm的红光透过率,且CeS与CoO·Al_(2)O_(3)质量比为1∶2时,红光透过率为39.2%,蓝光透过率为38.1%,红/蓝光透过比例为1.03;万能拉伸试验机测试结果发现CeS与CoO·Al_(2)O_(3)可改善PE棚膜的力学性能,其中拉伸强度较空白样提升约5.5%,断裂伸长率提升约16.8%,直角撕裂强度提升约3%,穿刺强度提升约21.8%;差示扫描量热仪表征结果显示添加CeS与CoO·Al_(2)O_(3)可提升PE氧化诱导期(Oit)达45 min以上,PE具有良好的耐热老化性能。上述测试表征结果表明:CeS与CoO·Al_(2)O_(3)的引入可明显提升PE棚膜的散光性能、力学性能、耐热稳定性能、红/蓝光透过率及透过比例。此外,可通过调控CeS与CoO·Al_(2)O_(3)的质量比获得不同红/蓝光质调控的PE功能棚膜。

LED红蓝光配比对番茄生长和光合的影响

以番茄品种‘普罗旺斯’为材料,在双拱钢架日光温室内进行人工补光试验,设置T1(2R3B,即红光/蓝光珠数配比R:B=2:3)、T2(4R1B)、T3(6R1B)、T4(7R1B)四组红蓝光处理,以不进行人工补光为对照(CK),探究温室番茄生长和光合响应最优的红蓝光配比。结果表明,在T1处理下35d后,番茄的株高、SPAD、蒸腾速率(Tr)和光化学淬灭系数(qP)较对照组分别显著提高26.7%、19.6%、107.6%和34.3%。在T3处理下35d后,番茄的茎粗、花朵数、净光合速率(Pn)、胞间CO_(2)浓度(Ci)、气孔导度(Gs)、实际光化学效率(ΦPSⅡ)和电子传输速率(ETR)较对照组分别显著提高26.9%、38.6%、133.7%、5.9%、183.3%、31.3%和30.9%。在T4处理下35d后,最大光化学效率(Fv/Fm)较对照组分别显著提高4.0%。在对设施番茄进行不同配比红蓝光补光处理下,较对照组可显著促进番茄的生长及光合作用,在本试验设置的2R3B、4R1B、6R1B、7R1B四组红蓝组合光处理中,6R1B(红/蓝光珠数配比R:B=6:1)处理下各项指标表现的综合效果最佳,可为温室番茄栽培LED补光提供一定的理论指导。

红蓝光促进陆地棉愈伤组织诱导和增殖

【目的】陆地棉(Gossypium hirsutum)的遗传转化技术存在转化周期长、转化效率低等问题,其中,愈伤组织增殖速度慢是导致棉花转化周期长的关键因素。探究陆地棉愈伤组织增殖的最适光照条件,为缩短棉花转化周期提供技术基础。【方法】以陆地棉受体品种WC的下胚轴为外植体诱导愈伤组织,设置红光、蓝光、红蓝光(1﹕1)和白光(CK)4种不同光照处理,研究不同光质下愈伤组织的增殖速度、形态特征,以及相关基因表达水平和相关酶活性的差异,解析光照对愈伤组织增殖的影响并获得最优光照条件。【结果】不同光质对诱导棉花外植体出愈和愈伤组织生长具有明显影响。在4种不同光照处理下,红蓝光相较其他光质具有更显著地促进外植体出愈和愈伤组织增殖的效果,表现为愈伤组织分化时间更短,7—15 d,即与其他处理存在明显表型差异,7 d愈伤组织鲜重红蓝光(0.39 g)>蓝光(0.34 g)>白光(0.24 g)>红光(0.23 g),15 d时,红蓝光(1.15 g)>蓝光(0.98 g)>白光(0.69 g)>红光(0.51 g),红蓝光照射下的愈伤组织鲜重是白光对照的1.65倍,比单一蓝光或红光照射下的愈伤组织鲜重增加16.5%或125.5%;与此相一致的是,红蓝光处理下,第二周的愈伤增殖率也最高,达14.67%,比红光处理(7.17%)增加1倍多。4种光质下,愈伤增殖及体胚再生相关基因的表达量,红蓝光处理均显示最高。此外,红蓝光处理下愈伤组织的过氧化氢酶(CAT)活性显著提高,活性氧(ROS)含量低于白光对照。【结论】不同光质条件下,棉花外植体的愈伤组织增殖速度不同,红蓝光(1﹕1)促进外植体出愈和愈伤增殖表现最优,其次为蓝光,再次为白光,单独的红光不利于棉花出愈和愈伤增殖。红蓝光(1﹕1)处理诱导光受体及其互作因子、愈伤增殖等相关基因的表达,增强愈伤组织内过氧化氢酶的活性,降低活性氧含量,促进细胞分裂,进而促进愈伤增殖。

不同绿蓝光比例对罗勒生长及其能源利用效率的影响

【目的】在红光(R,660 nm)保持定量的条件下,探究不同绿蓝光比例(G/B)对罗勒(Ocimum basilicum Linn.)生长、气孔特征、光合能力以及能源利用效率的影响,为植物工厂罗勒高效节能生产提供技术支撑。【方法】在植物工厂环境下,以罗勒为试验材料,将生长19 d的罗勒幼苗分别置于RB(R﹕G﹕B=8﹕0﹕8,设为对照处理)、RG1B7(R﹕G﹕B=8﹕1﹕7)、RG1B3(R﹕G﹕B=8﹕2﹕6)、RG1B1(R﹕G﹕B=8﹕4﹕4)、RG3B1(R﹕G﹕B=8﹕6﹕2)、RG7B1(R﹕G﹕B=8﹕7﹕1)和RG(R﹕G﹕B=8﹕8﹕0)7种不同光质组合处理中,光照强度设置为160μmol·m^(-2)·s^(-1),其中红光占50%,光照时间为16 h/d,光/暗期温度为25℃/23℃,相对湿度设定为65%,光期CO_(2)浓度设定为1000μmol·mol^(-1)。试验处理13 d后测量罗勒的光合作用参数,处理19 d后测量其生长指标、气孔特征以及能源利用效率。【结果】除RG1B3处理外,添加绿光处理比对照显著提升了罗勒的株高、叶面积和干鲜重,不同绿蓝光比例(G/B)处理的地上部干、鲜重分别比对照提高了19%—51%和26%—64%;但除RG处理外,不同G/B处理间的叶面积和干、鲜重差异不显著。低G/B处理(RG1B7)仅降低罗勒下层叶片反面的气孔密度,随着G/B的增大,下层叶片正面及上层叶片的气孔密度均降低。总体上,叶片氮含量随着G/B的增加而降低,叶片氮含量和气孔密度的降低导致罗勒的CO_(2)同化能力、光利用能力下降,降低程度总体上随着G/B的增加而增大。由于绿光LED的发光效率比蓝光低,总耗电量随着G/B的增加而增加,本试验中仅RG1B7处理比对照显著提高了25%的电能利用效率;除RG1B3处理外,不同G/B处理比对照提升了30%—57%的光能利用效率,提升程度在除RG外的不同G/B处理间无显著差异;与对照相比,RG3B1和RG处理提高了罗勒上层和下层叶片水分利用效率,其中RG3B1分别提高了58%和74%,RG分别提高了67%和90%。【结论】结合罗勒生长和能量利用效率数据可知,RG1B7处理可被认为是植物工厂罗勒生产较为适宜的光质组合。研究结果可为明确不同绿蓝光比例对罗勒生长、光合特性及能源利用效率的影响规律提供参考,也为完善植物工厂环境下罗勒高效节能生产光配方提供技术支撑。

红蓝光治疗慢性伤口疗效的Meta分析

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。

不同比例红蓝光夜间补光对番茄生长生理的影响

本试验以番茄‘冠群6号’为供试品种,在其行间放置不同红光(R)蓝光(B)比例(6R∶4B、7R∶3B、8R∶2B和9R∶1B)补光灯每日夜间补光6 h,研究不同比例红蓝光补光对设施番茄生长、光合特性、叶绿素荧光及果实品质的影响。结果表明:与不补光对照(CK)相比,不同比例红蓝光夜间补光对番茄不同时期各生长指标均有一定程度的影响,其中7R∶3B处理生长前期促进植株生长、增大叶面积,生长后期显著增加茎粗。幼苗期和营养生长旺盛期以红蓝光比例6∶4进行补光,番茄叶片的净光合速率、最大光化学效率和光系统Ⅱ潜在活性均最高;开花结果期以红蓝光比例7∶3补光,番茄叶片的净光合速率、最大光化学效率和光系统Ⅱ潜在活性最高。不同比例红蓝光补光对番茄果实品质均有提升作用,其中对平均单果重、纵横径、果实硬度、果形指数促进最大的处理为9R∶1B,对果实可溶性固形物、可溶性蛋白、VC含量促进最大的处理是7R∶3B,对可溶性糖、总酚含量促进最大的处理是8R∶2B。基于番茄生长及果实品质指标的隶属函数综合评价,7R∶3B处理即红蓝光比例7∶3为本研究最佳处理,能够较好地促进设施番茄生长和提高果实品质。

Low temperature-mediated repression and far-red light-mediated induction determine morning FLOWERING LOCUS T expression levels

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.