半根交替干旱对‘大久保’桃叶片中几种有机渗透调节物质的影响

 和良好水分条件的对照相比较, 半根交替干旱处理(ARS) 对‘大久保’桃叶片日出前水势无显著影响, 但显著高于全根干旱(WRS) 处理。WRS导致叶片中游离氨基酸、脯氨酸和可溶性糖含量显著增加和淀粉含量显著降低, 而ARS和对照之间叶片中游离氨基酸、脯氨酸、可溶性糖和淀粉含量均不存在显著性差别。此外, 叶片中游离氨基酸、脯氨酸和可溶性糖含量与日出前叶片水势呈显著或极显著负相关, 而淀粉含量与日出前叶片水势呈极显著正相关。上述结果表明, ARS条件下植株具有良好的水分供应能力, 并不存在积累上述有机物质进行渗透调节的现象。     

种植转基因番茄对温室土壤理化性质及养分的影响

以甘肃陇中地区长期种植的转基因和非转基因番茄的日光温室土壤为对象,在番茄生长的幼苗期、始花坐果期和结果期分别采集温室土壤(0~20cm),比较土壤理化性状和养分。结果表明:在土壤理化性状中,非转基因番茄在整个生育期会导致土壤pH值持续下降,而转基因番茄在幼苗期会导致土壤pH值明显下降,以后会逐渐升高,最终使土壤pH值与对照值接近,结果期转基因番茄土壤pH值的相对变化量极显著低于非转基因番茄;2种番茄都导致土壤水溶性盐总量先增加、后降低,转基因番茄土壤水溶盐的变化量在幼苗期、始花坐果期和结果期均极显著低于非转基因番茄;2种番茄都导致土壤有机质含量持续降低,且两者各生长阶段相对变化值差异不显著。在土壤养分中,2种番茄都导致土壤全磷、速效磷、全氮、水解氮、速效钾的含量持续降低,除了转基因番茄在始花坐果期、结果期土壤全磷含量相对变化量分别显著、极显著小于非转基因番茄外,其它养分在个生长阶段的相对变化量差异均不显著。因此,该地区温室在适当调节土壤盐分含量、科学合理施肥的情况下,可适当年限地连续种植转基因番茄。     

重水分胁迫下苹果树茎、叶水势的变化

对田间生长的3年生苹果树(红富士/M26/八棱海棠)在土壤干旱和湿润条件下的茎及叶片水势、气孔导度和净光合的日变化进行了测定。茎水势的测定采用外围新梢的直接取样测定法,以便同剪口处叶片的水势进行比较。测定结果表明,干旱土壤条件下的叶片水势稍低于土壤湿润的树,一般仅相差0.3MPa。而二个处理之间午间茎水势的差别则高达1～1.2MPa,表现出该指标对土壤干旱十分敏感。干旱条件下叶片气孔导度和净光合与土壤湿润的树也有明显差异。研究还发现,在水分严重亏缺条件下存在茎水势低于叶水势及一定压力下枝条木质部漏气现象。对这些现象的发生条件和可能原因进行了讨论。     

番茄砧木耐热性评价及热胁迫生理响应研究

南方地区番茄在春延后栽培和秋提前栽培中易受异常高温的影响,采用耐热砧木进行嫁接栽培可以提高番茄的耐热性。为筛选耐热性强的番茄砧木种质资源,本试验对20份番茄砧木种质的种子和幼苗进行热胁迫处理,根据热害表型和幼苗生长生理指标评价砧木种质的耐热性。结果表明,热胁迫抑制番茄砧木种子萌发,随着温度升高,种子发芽率明显降低。34 ℃时,除N3外的砧木种质种子发芽率降至50%以下;37 ℃时种子发芽率均降至24%以下,40 ℃时种子发芽率均为0。亚高温(34 ℃/28 ℃)和高温(37 ℃/28 ℃)胁迫下,G3、N3、Q2均表现强耐高温(HR),A1、Q3、Q4、Q5、Y4表现中耐高温(MR)或耐高温(R)。幼苗热害指数与株高、叶片丙二醛(MDA)含量呈极显著正相关,与叶片SPAD值、茎粗、全株鲜质量、全株干质量、叶片游离脯氨酸含量呈显著或极显著负相关。利用以上7项生长生理指标,采用隶属函数值法对供试种质的耐热性进行综合评价,种质G3、N3、Q2的耐热性居前3位,与亚高温胁迫的幼苗热害指数排序一致。综上,种质 G3、N3、Q2强耐高温,可作为选育耐热番茄砧木的骨干材料。     

锌胁迫下水培枳幼苗锌分布及矿质营养元素含量变化

为了解锌胁迫(缺乏或过量)下枳体内锌分布及其他矿质元素含量变化,以30d枳实生幼苗为试材,分别进行锌缺乏(0μmol·L-1)、对照(0.7μmol·L-1)和锌过量(70μmol·L-1)水培处理,70d后测定和分析。结果表明,枳幼苗根、茎和叶中锌含量随处理浓度升高而显著升高,不同器官锌含量为根茎叶,锌胁迫下植株地上部分含锌量比例增加。与对照相比,缺锌处理枳幼苗叶片K、Mn和Cu含量显著降低,叶片Fe含量显著升高,根系Mn含量显著上升,根系Cu含量显著下降。与对照相比,锌过量处理枳幼苗叶片P、Ca、Mg和Cu含量,茎P和K含量,根系Fe和Cu含量均显著升高;叶片K、Fe和Mn含量,茎Ca和Fe含量,根系K和Mn含量均显著降低。各器官不同处理间S含量差异无显著性。相关性分析显示,Zn和Cu含量在枳幼苗根、茎、叶中呈显著或极显著正相关;Zn和Fe含量在叶片和茎中呈极显著负相关,在根中呈极显著正相关。     

基于主成分分析立地条件对核桃幼苗生长影响的研究

为探明不同立地条件对核桃幼苗生长的影响，以“辽宁1号”核桃种子为试验材料，应用主成分分析的方法，研究了不同立地条件土壤相关指标与核桃叶片营养元素的关系。结果表明，山坡(未改造)核桃叶片内的含磷量最高，山顶核桃幼苗叶片中铁元素含量较高；在核桃幼苗生长状况方面，山坡(客土)的核桃幼苗株高最高，山谷的核桃幼苗干径显著高于其他3种立地条件上的核桃幼苗。结合相关性分析得出，土壤中的钙、铜含量与核桃幼苗的发芽率呈显著正相关关系，铁含量与核桃幼苗的株高呈显著负相关关系，土壤中钙、铁、铜含量与核桃幼苗的干径呈显著正相关关系；土壤的pH与叶片中钾、钙的含量呈正相关关系，但与叶片中铁、锰、铜含量呈显著负相关关系，叶片中磷、钾、钙与土壤中磷含量呈显著正相关关系(P<0.05)。最后经过主成分分析得出，山谷的含水量、有机质及氮等矿质元素含量适中适宜核桃幼苗的生长，其次是山坡(未改造),然后是山坡(客土),最后是山顶。     

“黄冠”梨树茎直径微变化规律研究

以"黄冠"梨树为试验材料,分别设定2个处理:充分供水处理(Well-irrigation,WI)和逐步干旱处理(Gradual-drought,GD),通过连续监测"黄冠"梨树茎直径、土壤水势(SWP)和日平均温度(T)等环境因子,研究梨树的茎直径微变化规律,为进一步利用梨树茎直径微变化来指导梨树节水灌溉提供参考依据。结果表明:WI处理和GD处理的日变化趋势有明显差异,GD处理的茎直径日最大收缩量(MDS)明显小于WI处理。GD处理的茎直径日最大值(MXSD)随着时间的延长,呈先升后降的抛物线趋势;随着土壤水势的下降,GD处理的茎直径日最大收缩量、日增长量(DI)和日复原时间(RT)与土壤水势之间分别呈很好的开口抛物线、斜率为正和斜率为负的线性关系趋势;GD处理的茎直径日最大收缩量与日平均温度、空气相对湿度(RH)和光照强度(L)呈显著的正相关,而WI处理的茎直径日最大收缩量与日平均温度、空气相对湿度和光照强度呈显著的负相关;WI处理的DI,不受空气相对湿度、光照强度和风速的影响,但受日平均温度的影响显著,呈负相关;GD处理的DI,不受空气相对湿度和风速的影响,但显著受日平均温度和光照强度的影响,为负相关。综上所述,在GD处理中,土壤水势与DI之间的线性关系更具实际意义,可以用DI作为指导梨树灌溉的指标。     

叶、果水势和叶片光合指标对黄金梨黄顶病发病的影响

为探讨叶、果水势和叶片光合指标对黄金梨果实黄顶病发生的影响机理,对历年来发病较重植株(B)和较轻植株(A)的叶、果水势差和叶片的部分光合指标进行了测定比较研究。结果表明:在黄金梨果实的发育过程中,无论发病轻、重的黄金梨树,其果实的水势始终高于叶片,但发病重的叶片水势较低,叶、果水势差较大;处理A叶片和果实的水势差值始终极显著小于处理B;处理A的叶片净光合速率、水分利用效率和羧化效率始终高于处理B。相关性分析结果显示,发病轻处理的叶、果水势差异与果实发病率呈极显著相关(r=0.9153)。而发病重处理的叶、果水势差异与果实发病率呈显著相关(r=0.641)。叶片和果实水势差的大小与果实发病率呈显著正相关(r=0.6339);2个处理的净光合速率、水分利用效率和羧化效率与果实发病率均呈极显著负相关,相关系数分别为r=-0.9579、r=-0.9644和r=-0.9243。     

生物菌肥和土壤调理剂对番茄幼苗生长、叶片Cd和Cu含量的影响

探讨EM生物菌肥、土壤调理剂及其配施处理对番茄幼苗生长、叶片Cd和Cu含量的影响,为应用生物菌肥和土壤调理剂处理缓解土壤中重金属影响提供参考。结果表明:在Cd和Cu胁迫下,生物菌肥和土壤调理剂及其配施处理对促进番茄幼苗生长无显著作用,但"生物菌肥+土壤调理剂"配施处理能明显提高番茄幼苗叶片叶绿素含量,有利于促进光合作用;同时也能明显降低番茄幼苗叶片中的Cd和Cu含量,减缓其在叶片器官中的累积。综上,生物菌肥和土壤调理剂配施处理能提高番茄幼苗叶片叶绿素含量,对番茄幼苗叶片中Cd和Cu有减低作用。     

水分胁迫对番茄生长及光合系统结构性能的影响

以普通番茄和樱桃番茄为试材，分别在正常供水和水分胁迫条件下，研究不同生态型番茄生长指标及光合系统结构的变化。水分胁迫显著抑制了番茄的生长，叶片水势及叶片相对含水量显著下降，     

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.     

Relationship between renal hypertension and cardiac α1-adrenoceptor autoantibodies in rats

AIM: To examine the autoantibody against α₁-adrenoceptor and its biologic activities during the development of renal hypertension. METHODS: Renal hypertension of rat was achieved by clipped renal artery, the titre of autoantibody to α₁-adrenoceptor was detected using ELISA immunoassay. Furthermore, the biological offects of these autoantibodies on cultured cardiomyocytes were also examined. RESULTS: After two weeks of clipping renal arteries, both the frequency of occurrence and the titre of autoantibodies to cardiac α₁-adrenergic receptor were significantly increased as compared with the control of pre-treatment. The increased autoantibodies lasted for several weeks and then automatically decreased gradually to the pre-clipping level at 12 weeks. The biological effects of these autoantibodies displayed an "agonistic-like" activities on the beating frequency of cultured neonatal cardiomyocytes. CONCLUSION: Autoantibodies against α₁-adrenoceptor may play a role in the elevation of peripheral vascular resistance and in the development of cardiac hypertrophy in rats with renal hypertension.     

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.     

Influence of Mineral Nutrients on Strawberry Fruit Quality and Their Accumulation in Plant Organs

Abstract

This review is based partly on complete articles and partly on abstracts. Three of the 60 articles deal with the total uptake of elements in strawberry plant organs in two different strawberry production systems, both considered as optimal concerning amount and balance of elements. The effect on fruit quality may be dramatic if the level of a particular element is outside this range, but there may also be effects initiated by differences within the optimal range of elements. Most articles refer to product oriented quality, but some focus on consumer oriented quality, as discussed by Shewfelt (1999). The discussion here is on a general basis, so one should keep in mind that there are cultivar differences and that specification of nutrition ideally should mirror the needs of a single cultivar, or a group of cultivars with similar requirements. Also, to get a complete understanding of the subject future reviews should embrace a broader access of information including the effect on plant development of individual elements, such as the role of calcium in fruit firmness and its importance in cell wall structure. However, the intention here is to narrow the information to results that suggest a direct connection between nutrient uptake and fruit quality.     

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.     

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.     

Mixed-severity fire regime in a high-elevation forest of Grand Canyon,Arizona, USA

Fire regime characteristics of high-elevation forests on the North Rim of the Grand Canyon, Arizona, were reconstructed from fire scar analysis, remote sensing, tree age, and forest structure measurements, a first attempt at detailed reconstruction of the transition from surface to stand-replacing fire patterns in the Southwest. Tree densities and fire-/non-fire-initiated groups were highly mixed over the landscape, so distinct fire-created stands could not be delineated from satellite imagery or the oldest available aerial photos. Surface fires were common from 1700 to 1879 in the 4,400 ha site, especially on S and W aspects. Fire dates frequently coincided with fire dates measured at study sites at lower elevation, suggesting that pre-1880 fire sizes may have been very large. Large fires, those scarring 25% or more of the sample trees, were relatively infrequent, averaging 31 years between burns. Four of the five major regional fire years occurred in the 1700s, followed by a 94-year gap until 1879. Fires typically occurred in significantly dry years (Palmer Drought Stress Index), with severe drought in major regional fire years. Currently the forest is predominantly spruce-fir, mixed conifer, and aspen. In contrast, dendroecological reconstruction of past forest structure showed that the forest in 1880 was very open, corresponding closely with historical (1910) accounts of severe fires leaving partially denuded landscapes. Age structure and species composition were used to classify sampling points into fire-initiated and non-fire-initiated groups. Tree groups on nearly 60% of the plots were fire-initiated; the oldest such groups appeared to have originated after severe fires in 1782 or 1785. In 1880, all fire-initiated groups were less than 100 years old and nearly 25% of the groups were less than 20 years old. Non-fire-initiated groups were significantly older (oldest 262 years in 1880), dominated by ponderosa pine, Douglas-fir, or white fir, and occurred preferentially on S and W slopes. The mixed-severity fire regime, transitioning from lower-elevation surface fires to mixed surface and stand-replacing fire at higher elevations, appeared not to have been stable over the temporal and spatial scales of this study. Information about historical fire regime and forest structure is valuable for managers but the information is probably less specific and stable for high-elevation forests than for low-elevation ponderosa pine forests.This revised version was published online in May 2005 with corrections to the Cover Date.     

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.