低温弱光下辣椒叶片光合色素的变化及与品种耐性的关系

以12个耐低温弱光性不同的辣椒品种为试材,模拟日光温室低温弱光逆境,研究了12个辣椒品种叶片光合色素含量的变化规律及与品种耐低温弱光性之间的关系。结果表明,温度15 ℃/5 ℃(昼/夜)、光照强度100 μmol?m-2?s-1处理使辣椒叶片的Chla、Chlb、ChlT含量降低,但降低值与辣椒品种耐低温弱光性强弱之间无显著相关性;低温弱光处理5 d的Chla/b相对于处理前的相对增加值与辣椒品种耐低温弱光性之间呈显著正相关;低温弱光下辣椒叶片的Car含量降低,Car/ChlT显著减小,Car含量越低、Car/ChlT越小或其相对于处理前的降低值越大,则品种的耐低温弱光性越强。     

PEG浸种对低温弱光下辣椒幼苗叶片部分生理指标的影响

以湘研1号辣椒为试验材料,用25%聚乙二醇（PEG）溶液处理种子,研究了在低温弱光胁迫下PEG处理对辣椒幼苗与抗冷性有关的部分生理指标的影响。结果表明：在15℃/5℃（昼/夜）低温,100μmol·m^-2·s^-1弱光下,辣椒幼苗地上部干质量、地下部干质量、株高、茎粗均降低;辣椒幼苗叶片细胞膜透性、丙二醛(MDA)和脯氨酸(Pro)含量升高,并随低温弱光处理时间的延长而增加;超氧化物歧化酶（SOD）和过氧化物酶(POD)活性呈现先升高后降低的趋势;可溶性蛋白含量呈逐渐下降趋势。PEG浸种处理可使辣椒幼苗地上部干质量、地下部干质量、株高、茎粗和叶片的SOD、POD活性、可溶性蛋白含量的下降幅度均较低温弱光对照显著减小,细胞膜透性、MDA与Pro含量的增加幅度均较对照显著降低,表明PEG浸种处理能够提高辣椒幼苗对低温弱光的适应能力。     

不同品种辣椒幼苗光合特性及弱光耐受性的差异

 在不同弱光处理条件下, 利用L I26400型便携式光合仪研究了弱光对4个辣椒品种幼苗光响应曲线、CO₂ 响应曲线等光合特性的影响, 结果表明弱光下辣椒的光补偿点(LCP) 、光饱和点(LSP) 、光饱和光合速率、CO₂ 补偿点(CCP) 、CO₂ 饱和点(CSP) 、暗呼吸速率(Rd ) 、羧化效率(CE) 、RuBP羧化酶活性、RuBP最大再生速率均下降, 表观量子效率(AQY) 上升, 并且弱光下辣椒净光合速率( Pn)的下降是RuBP羧化限制和再生限制的共同结果。另外随光照的减弱, 辣椒叶片叶绿素(Chl. ) 含量上升,叶绿素a /b比值(Chl. a /b) 和比叶重( SLM) 下降。弱光下LCP和Rd 相对较低、AQY和CE较高的辣椒品种可能具有耐弱光的优势。     

弱光胁迫对七个辣椒组合的生长发育及产量的影响

以驻马店市农业科学院园艺所近年来培育的7个辣椒组合(品种)为试材,利用遮阳网模拟弱光胁迫,调查了在弱光胁迫下辣椒植物学性状及产量性状,以株高、茎粗作为参考指标,以叶面积、比叶干质量作为重要指标,以产量、叶绿素a/b值作为主要指标,对其弱光耐受性进行了综合评价。结果表明:弱光逆境胁迫导致辣椒植株增高、茎秆变细、叶面积增大、比叶干质量降低、产量及叶绿素a/b值均降低;且叶绿素a/b值与产量的变化幅度基本一致,该方法可用来鉴定辣椒不同组合的耐弱光性能。     

高湿和弱光对葡萄叶片某些光合特性的影响

 高湿和弱光导致葡萄叶片RubisCO含量、净光合速率、气孔导度、胞间co2浓度、叶绿素a和叶绿素b含量、叶绿素a／b下降。叶片净光合速率与气孔导度、胞问co2浓度、RubisCO含量之间存在着显著的正相关。较低湿度和光照胁迫后，于正常生长条件下能较快地恢复，严重高湿和弱光胁迫后很难恢复到对照水平。     

弱光条件下辣椒幼苗叶片的气体交换和叶绿素荧光特性

在人工气候室内, 研究了人工模拟弱光处理(75～100μmol·m^-2 ·s^-1 , 对照光强450～500μmol·m^-2 ·s^-1 ) 对不同基因型辣椒(Capsicum annuum L. ) 叶片光合作用气体交换、叶绿素荧光参数以及叶绿素含量的影响。结果表明, 弱光逆境下生长的辣椒幼苗净光合速率( Pn) 、暗呼吸速率(Rd) 、夜间呼吸速率(Rn) 不同程度下降, PSⅡ实际光化学效率( ФPSⅡ) 、光合电子传递速率( ETR) 和光化学猝灭系数( qP) 降低, 激发能向光化学反应分配的比例减少, 热耗散增加, 而弱光对PSⅡ的最大光化学效率( Fv/Fm) 无显著影响。辣椒叶片ФPSⅡ及ETR对光强( PPFD) 的响应曲线表明, ФPSⅡ随PPFD的升高而下降, 弱光下生长的叶片下降幅度较对照正常光照下的叶片大; 弱光下生长叶片的的电子传递速率的光饱和点低于正常光照下的叶片, 相应的饱和电子传递速率也较低。弱光处理使辣椒功能叶片SPAD值降低, 叶绿素合成受到抑制。弱光耐受性较好的材料, 如‘伏地尖’和‘上海圆椒’在弱光下Pn下降较少,并且有着相对较高的Fv/Fm以及ETR值。     

低温寡照胁迫对设施番茄花期叶片衰老特性的影响

为了研究低温寡照复合灾害对设施番茄叶片衰老特性的影响,以‘金粉5号’番茄为试材,于2015年2—5月在南京信息工程大学利用人工气候室设置了低温(昼/夜温度分别为18/8℃、16/6℃、14/4℃、12/2℃)和寡照(PAR分别为400、200μmol·m-2·s-1)双因素交互试验,系统测定低温寡照处理下设施番茄叶片细胞色素、电导率以及抗氧化酶活性,并利用主成分分析计算各处理的综合得分。结果表明:短时间内不同低温寡照组合下低温寡照处理叶绿素含量有所波动,随着低温寡照胁迫时间的延长,番茄叶片叶绿素a、叶绿素b含量均有下降,叶绿素a/b也有不同程度的下降,其中昼夜温度为12/2℃,光合有效辐射为200μmol·m-2·s-1处理10d的叶绿素a、叶绿素b含量最小,分别比CK减少36.31%、36.11%;低温寡照处理下,叶片组织的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性、丙二醛(MDA)含量以及相对电导率均有不同程度升高,昼夜温度为12/2℃,光合有效辐射为200μmol·m-2·s-1的处理的各指标始终处于较高水平,处理10d时较CK分别升高了2.09、3.82、3.70、2.49、1.75倍。通过各低温寡照处理的叶绿素总量、保护酶活性以及相对电导率指标计算出各处理的综合得分得出各处理对番茄影响的严重程度排名,在同一寡照水平上,温度越低,番茄植株受的伤害越大;同一低温水平上,光合有效辐射越低,番茄植株受的伤害程度越大;低温对番茄的胁迫要大于寡照对番茄的胁迫。该研究可为番茄抵御低温寡照复合灾害提供科学的理论依据。     

外源海藻糖对低温胁迫下哈密瓜幼苗光合作用的影响

以“西州密25号”幼苗为试材,采用0、5、10、20 mmol·L^-1外源海藻糖预处理3 d,在昼/夜温度分别为15℃/10℃、10℃/5℃、5℃/1℃低温胁迫1 d和3 d时测定幼苗叶片的光合色素含量、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO₂浓度(Ci),研究了在低温条件下外源海藻糖对哈密瓜(Cucumis melon var.saccharins)幼苗光合作用的影响,明确其耐寒调控机理,以期为缓解倒春寒气候对哈密瓜幼苗造成的伤害提供参考依据。结果表明：在未喷施外源海藻糖情况下,低温胁迫显著抑制了叶片的光合能力,且叶绿素b(Chl b)含量显著增加,随着温度的降低,其它光合色素含量与Pn、Gs、Ci和Tr均显著下降;与未喷施外源海藻糖相比,外源海藻糖可对低温胁迫下哈密瓜幼苗的一系列光合指标产生影响,适宜浓度的海藻糖可明显提高光合色素含量,增强哈密瓜叶片Pn、Gs和Tr。通过隶属函数综合评价可知,低温胁迫下5、10 mmol·L^-1外源海藻糖明显促进了叶绿素a(Chl a)、Chl b、类胡萝卜...     

‘巨峰’葡萄盛花后弱光胁迫对叶片光合生理及光合酶基因表达的影响

为了探明弱光胁迫对葡萄叶片光合生理的影响,以4年生‘巨峰’葡萄为材料,在盛花后进行20 d 70%遮光作为弱光处理,然后恢复至未遮光植株(对照)水平,测定果实品质和叶片的光合参数、叶绿素荧光、叶绿素含量、叶片糖含量及组分、光合酶基因及蔗糖磷酸合成酶基因表达等。结果发现,弱光处理导致成熟期葡萄果实可溶性固形物含量降低,可滴定酸含量升高,果皮花色苷含量减少,果实纵径降低。随着弱光时间延长,叶片叶绿素b含量增加,叶绿素a/b值下降,光合速率和光化学效率降低,叶片中可溶性糖含量降低,Rubisco大、小亚基,PRKase,SPS1-2,SPS3等基因表达受到抑制;光照恢复至对照水平10 d后,光合速率、光化学效率及可溶性糖含量略有上升,光合酶基因表达得到部分恢复;恢复光照50 d后,叶绿素a/b、叶片可溶性糖含量、部分光合酶基因和SPS表达等基本与对照水平一致,仅Rubisco大亚基1(RbcL1)表达仍低于对照。说明长时间弱光处理对葡萄叶片光合中心的损伤短期内不可逆,部分光合酶和蔗糖代谢关键酶基因表达受到抑制,叶片光合能力下降,光合产物合成与积累减少,进而导致了葡萄果实变小,品质降低。     

铝胁迫对辣椒叶绿素及叶绿素荧光的影响

在不同浓度铝胁迫下,以‘红辣椒王ⅡF1’、‘卡其特长条辣906’、‘汴椒1号’和‘苏长红’4个品种为材料,研究辣椒叶片叶绿体含量、叶绿素荧光参数的动态变化,以期为研究辣椒铝胁迫提供理论依据。结果表明,铝处理抑制辣椒叶片叶绿素的合成,从而降低辣椒叶片叶绿素的含量。辣椒叶片叶绿体色素(叶绿素a、叶绿素b、叶绿素a+b、叶绿素a/b)含量在低铝浓度(50μmol/L)下呈升高趋势,高铝浓度(200μmol/L)下则均下降。荧光参数的研究表明,随着铝胁迫的增加,初始荧光(F_0)随之增大,最大荧光(F_m)、原初光能转化效率(F_v/F_m)下降,植株抵抗逆境的能力下降,光合电子传递随之减小,最终导致光合速率下降。     

Effects of radiation from 188Re on smooth muscle cell proliferation

AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β^-particles emission from ¹⁸⁸Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by ¹⁸⁸Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [³H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of ¹⁸⁸Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from ¹⁸⁸ Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G₀/G₁ arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation.     

Effect of L-Arg on plasma content of endothelin and expression of c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy

AIM:To study the effect of L-Arg on plasma content of endothelin (ET) and the expression of proto-oncogene c-fos mRNA in the left ventricle of rats with renovascular hypertensive hypertrophy. METHODS: The level of c-fos mRNA were measured by in situ hybridization. The ET in plasma were measured by radioimmunoassay. RESULTS:After eight weeks of treatment with L-Arg, the expression of c-fos decreased markedly (P＜0.01). The ET content in plasma also decreased significantly by L-Arg(P＜0.01).CONCLUSION: Plasma ET content and the expression of c-fos in the left ventricle of rats with renovascular hypertensive hypertrophy could be decreased by L-Arg administration.     

多效唑对猕猴桃离体试管苗生长及内源激素的影响

多效唑（ＰＰ３３３）处理猕猴桃试管苗，降低了其生长强度；植株体内的ＧＡ３、ＩＡＡ和ＺＴ含量下降，ＡＢＡ的含量上升，乙烯释放率增加；并且能降低外源的ＧＡ３和ＩＡＡ促进生长的作用，而外源的ＧＡ３和ＩＡＡ又能不同程度地逆转多效唑的抑制作用，使植株恢复生长。     

Proteomic analysis between pathological scars and normal skin

AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars.     

Compositional and Functional Properties of Saskatoon Berry and Blueberry

Abstract

Saskatoon berry (Amelanchier alnifolia Nutt., Rosaceae) and blueberry (Vaccinium corymbosum L., Ericaceae) are substantially equivalent in all characteristics that are important to the consumer, including fruit color, shape, size, nutrition, texture, and uses. In addition, both fruits are native to North America and they have practically identical historical uses and known health benefits. Their composition, processing, nutritional value and metabolism, intended uses, and levels of undesirable substances are compared.     

Cryopreservation of shoot apices of hawthorn in vitro cultures originating from East Asia

The objective of this study was to establish a cryopreservation protocol for hawthorn shoot apices (Crataegus pinnatifida Bge.). Cryopreservation was carried out via encapsulation–dehydration, vitrification, and encapsulation–vitrification on shoot apices excised from in vitro cultures. We began by showing that cold-acclimation enhanced the regrowth of cryopreserved apices from 10.0 to 65.5% in encapsulation–dehydration. We then decided that the encapsulation–dehydration method was an optimal cryopreservation method for hawthorn shoot apices in terms of its high recovery after cryopreservation as well as its ease of use compared with vitrification and encapsulation–vitrification. In encapsulation–dehydration, the protocol leading to optimal regrowth was as follows: after cold-acclimation at 5 °C in the dark for 2 weeks, excised shoot tips were pretreated for 24 h at 25 °C on hormone-free Murashige and Skoog [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tobacco tissue culture. Physiol. Plant. 15, 473–497] (MS) basal medium with 0.4 mol/L sucrose, then encapsulated and precultured in liquid MS medium with 0.8 mol/L sucrose for 16 h at 25 °C. Precultured beads were dehydrated for 6 h at 25 °C in the dessicator containing 50 g silica gel to a moisture content of 15.3% (fresh-weight basis) before cryostorage for 1 h. In addition, we examined the effect of adding glycerol to both the alginate beads and loading solution to enhance regrowth after cryopreservation in encapsulation–dehydration. In the present study, it was shown that adding 0.5 mol/L glycerol resulted in high regrowth percentages (82.5–90.0%) in four Crataegus species.     

Coupling past management practice and historic landscape change on John F. Kennedy Space Center,Florida

Historic landcover dynamics in a scrubby flatwoods (Tel-4) and scrub landscape (Happy Creek) on John F. Kennedy Space Center were measured using aerial images from 1943, 1951, 1958, 1969, 1979, and 1989. Landcover categories were mapped, digitized, geometrically registered, and overlaid in ARC/INFO. Both study sites have been influenced by various land use histories, including periods of range management, fire suppression, and fire management. Several analyses were performed to help understand the effects of past land management on the amount and spatial distribution of landcover within the study sites. A chi-squared analysis showed a significant difference between the frequency of landcover occurrence and management period. Markov chain models were used to project observed changes over a 100-year period; these showed current management practices being effective at Tel-4 (restoring historic landscape structure) and much less effective at Happy Creek. Documenting impacts of past management regimes on landcover has provided important insight into current landscape composition and will provide the basis for improving land management on Kennedy Space Center and elsewhere.     

Metallothionein inhibits homocysteine-induced proliferation of rat vascular smooth muscle cells

AIM:To investigate the effect of metallothionein(MT) on proliferation of rat vascular smooth muscle cells (VSMCs) stimulated by homocysteine and its mechanism. METHODS:VSMCs proliferation was measured by [³-H]-TdR incorporation, mitogen-activated protein kinase(MAPK)activity were determined by immunoprecipitation method, the intracellular contents of MT and malondialdehyde (MDA)were assayed by -hemoglobin saturation method and TBA reaction, respectively, and lactate dehydrogenase (LDH) leakage was measured by NADH oxidation. RESULTS:Hcy(10^-6-10^-4 mmol/L) stimulated [³-H]-TdR incorporation by the VSMCs in a concentration-dependent manner. Compared with control, [³-H]-TdR incorporation in VSMCs treated with 0.1 mmol/L Hcy was increased by 4.2 fold (P＜0.01). Meanwhile, Hcy enhanced MAPK activity, MDA formation and LDH release (P＜0.01)in a concentration-dependent manner. Treatment of VSMCs with MT alone did not change above parameters, compared with control. However, MT (10^-6-10^-4 mol/L)attenuated significantly Hcy-stimulated proliferation of VSMCs (P＜0.01)in a concentration-dependent manner. And MT inhibited obviously Hcy-induced activation of MAPK activity, MDA formation and LDH release. Preincubation of VSMCs with 0.5 mmol/L ZnCl₂ for 6 h induced an increase cellular MT content by 5.7-fold (P＜0.01). The MT-overexpressed VSMCs resisted Hcy-stimulating action on MAPK activity, MDA formation and LDH leakage (P＜0.01). CONCLUSION:These results show that MT has an inhibitory effect on Hcy-induced VSMCs proliferation, and that MT could inhibit Hcy-stimulated MAPK activity and lipid peroxidation.     

XBP-01 accelerated apoptosis induced by oxidized low density lipoprotein in vascular smooth muscle cells

AIM: Previous studies performed with XBP-01 in vitro indicated that XBP-01 could inhibit vascular smooth muscle cells from being transformed into foam cell and could eliminate the atherosclerotic plaque in C57BL/6J mouse. This experiment is to investigate its mechanism of eliminating plaques in vitro. METHODS: The cultured porcine artery smooth muscle cells incubated with XBP-01 of 0.1 mg/L for 24 h after preincubated with oxidized low density lipoprotein of 15 mg/L for 72 h in vitro. The samples were analyzed by fluorescence microscope, confocal microscope system and flow cytometry. RESULTS: Apoptosis was triggered by being incubated with oxidized low density lipoprotein and this process was accelerated additionally by being incubated with XBP-01. CONCLUSION: XBP-01 can be effective in eliminating atherosclerotic plaque by accelerating the process in which oxidized low density lipoprotein induced smooth muscle cell apoptosis.     

The effect of exposure on landscape scale soil surface temperatures and species distribution models

Species distribution models (SDMs) often use elevation as a surrogate for temperature or utilise elevation sensitive interpolations from weather stations. These methods may be unsuitable at the landscape scale, especially where there are sparse weather stations, dramatic variations in exposure or low elevational ranges. The goal of this study was to determine whether radiation, moisture or a novel estimate of exposure could improve temperature estimates and SDMs for vegetation on the Illawarra Escarpment, near Sydney, Australia. Forty temperature sensors were placed on the soil surface of an approximately 12,000 ha study site between November 2004 and August 2006. Linear regression was used to determine the relationship with environmental factors. Elevation was correlated more with moderate temperatures (winter maximums, summer minimums, spring and autumn averages) than extreme temperatures (summer maximums, winter minimums). The correlation (r ²) between temperature and environmental factors was improved by up to 0.38 by incorporating exposure, moisture and radiation in the regressions. Summer maximums and winter minimums were predominately determined by exposure to the NW and coastal influences respectively, while exposure to the NE and SW was important during other seasons. These directions correspond with the winds that are most influential in the study area. The improved temperature estimates were used in Generalised Additive Models for 37 plant species. The deviance explained by most models was increased relative to elevation, especially for moist rainforest species. It was concluded that improving the accuracy of seasonal temperature estimates could improve our ability to explain the patchy distribution of many species. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.