60Co-γ射线辐照百合鳞茎诱变育种研究

以切花"西伯利亚"种球为试材,采用60Co-γ射线辐照处理进行辐射诱变育种试验,研究了不同的诱变剂量对百合种球成活及植株生长发育的影响。结果表明:用60Co-γ射线辐射剂量为5Gy诱变"西伯利亚"种球比较合适。经4、5、6Gy 60Co-γ处理对百合植株的生长和发育出现较明显的辐射损伤,随着辐照剂量的增加,植株成活率、株高、叶片数、花蕾数、开花株率、花径相应减少,而出苗时间则增加,成活率分别为80%、52%、20%。     

东方百合X射线急性辐照后代的生长及POD同工酶特性研究

运用X射线对东方百合"索邦"离体不定芽进行急性辐照,并对辐照后的百合不定芽继代材料的生长及过氧化物(POD)同工酶酶谱进行分析。结果表明:1.76 Gy剂量处理东方百合芽高增量较对照显著增大,不定芽增殖无显著性变化,其它剂量处理相关生长指标与对照无显著性差异。POD同工酶酶谱分析发现,1.76 Gy剂量处理与对照相似系数较小,POD同工酶与对照的差异最大。     

低剂量60Co-γ辐照刺激拟南芥植株生长的效应

以拟南芥为试材,以0、50、150Gy剂量~(60)Co-γ辐照拟南芥种子,研究其对拟南芥植株生长发育的影响。结果表明:与对照相比,50Gy辐照处理显著增加了拟南芥植株高度、莲座叶长度、角果长度、种子数量以及叶片光合色素含量;150Gy辐照拟南芥的各项生长和生理指标显著降低,表明高剂量辐照处理抑制了拟南芥植株的生长。说明低剂量的~(60)Co-γ辐照显著促进拟南芥植株的营养生长和生殖生长。     

春兰离体根状茎辐射及EMS诱变方法建立

以野生春兰茎尖培养所得根状茎为材料,用10、20、30、40 Gy 60Coγ-射线进行辐照,以不经辐照为对照.处理材料培养在1/2MS+NAA 5 mg/L上进行增殖,经30 d后统计重量及生长点数,同时转入1/2MS+NAA 0.2 mg/L+BA 3mg/L进行分化培养,经45 d后统计分化出的苗数.结果表明:随着辐照剂量增大,根状茎的增殖特别是新生长点的形成受抑制,苗分化均略有促进,但未达显著水平,高剂量(30 Gy)将严重抑制增殖与分化,20 Gy应为春兰根状茎辐照诱变的最适剂量.EMs处理分别以0.6%、0.8%浸泡6 h和8 h,以磷酸缓冲液浸泡为对照,结果表明,处理与对照差异显著,随着浓度的增大,根状茎的死亡率明显提高,0.8%浸泡6 h与8 h之间差异不显著.     

太空环境对仙客来诱变效应的研究

以仙客来干种子为试材,利用"神舟八号"飞船搭载进行太空诱变处理,以此探究太空环境对仙客来造成的诱变效应。结果表明:太空诱变产生的M1代仙客来植株在花色和花形上与对照株相比表现出明显的表观性状差异;对突变株进行的RAPD(Random amplified polymorphic DNA)试验分析中,28条随机引物中有27条引物扩增出现多态性,总共扩增出156条条带,其中91条呈现出多态性,多态性比率达到58.33%。所有突变株的DNA分子均发生了显著变化,变异率从23.08%到33.97%不等。综合分析显示,太空环境对当代植株造成了显著的诱变效应,经辐照后的植株在分子水平上均发生了明显的变异,而基因组的改变进一步导致了植株表观性状的变异。     

~(60)Co-γ射线和Fe~+对番茄生物学效应及抗晚疫病研究

为探讨不同剂量~(60)Co-γ射线和Fe~+对番茄生长发育及其抗晚疫病的影响,利用40 Gy、60 Gy、80 Gy、1 00 Gy剂量的~(60)Co-γ射线和4Mev9×10~(12)剂量的Fe~+对番茄品种‘青苹果'和‘大黄888'的种子进行辐照,对辐照种子的出苗率、植株生长特性、果实特性和抗晚疲病性进行测定。结果表明:不同剂量辐照对同一品种的影响差别较大,同一辐照剂量的处理对不同品种的影响不同。经过60 Gy剂量的~(60)Co-γ射线辐照的‘大黄888'出苗率最高;4Mev9×10~(12)剂量的Fe~+辐照的‘青苹果'和‘大黄888'出苗率均大于对照处理;60 Gy剂量的~(60)Co-γ射线辐照和80 Gy剂量的~(60)Co-γ射线辐照对‘青苹果'和‘大黄888'的株高值均大于对照处理;经过不同剂量的~(60)Co-γ射线辐照和4Mev9×10~(12)剂量的Fe~+辐照,‘青苹果'和‘大黄888'的叶形指数可能会不同程度地变小;辐照过的‘青苹果'的茎粗均小于对照处理,而经过辐照的‘大黄888'的茎粗均大于对照处理。辐照过的‘青苹果'坐果数增加,而经过辐照的‘大黄888'则坐果数降低;用1 00 Gy剂量的~(60)Co-γ射线辐照的‘青苹果'抗晚疲病性要比对照处理好,而除了Mev9×10~(12)剂量的Fe~+辐照‘大黄888'处理、40 Gy剂量的~(60)Co-γ射线辐照‘大黄888'处理和1 00 Gy剂量的~(60)Co-γ射线辐照‘大黄888'处理的抗晚疫病性与对照相似外,其他辐照处理的抗晚疫病性均有下降。     

~(60)Coγ辐射对不同品种草莓离体叶片再生及芽生长的影响

以丰香和章姬草莓的无根无菌苗为试材,用10～40Gy 60Coγ射线辐照处理,以未辐照为对照,研究了60Coγ射线辐射对草莓叶片再生及植株继代增殖的影响。结果表明,叶片对辐射敏感,且丰香叶片比章姬叶片敏感,叶片再生的半致死剂量为10～20Gy;辐照后不同时间取叶接种,丰香叶片的不定芽再生率在剂量10Gy呈上升趋势,而其他剂量则几乎未见有变化,章姬在剂量10～30Gy,叶片的不定芽再生率提高较大,40Gy仍表现轻微下降;适宜的辐射剂量对草莓试管苗增殖有促进作用。     

波士顿蕨~(60)Co-γ射线辐射育种研究

以波士顿蕨(Nephrolepis exaltata‘Bostoniensis Murano’)的绿色球状体(Green Globular Bodies,GGB)为辐照材料,采用不同剂量的~(60)Co-γ射线处理,结合组织培养技术进行育种研究。结果表明:绿色球状体辐照半致死剂量约为128 Gy。随着辐照剂量的增加,绿色球状体的增殖和分化受到抑制。绿色球状体辐射表型损伤表现为:颜色变深,变紧实,增殖和分化受抑制;细胞学损伤表现为:胚性细胞减少,出现微核。50~200 Gy剂量下,随着辐照剂量的增加,绿色球状体分化植株变矮,叶形变异率增加。在150 Gy剂量下筛选得到叶片变异性状显著的突变体Neg1。     

60Co-γ辐照对火龙果种子萌芽生长的影响

为探明60Co-γ射线辐照对不同品种火龙果种子的辐射效应,以"蜜红""蜜宝""翠蜜""金都一号""富贵红""大红""燕窝果"7个品种火龙果新鲜种子为材料,分别经0、25、50、100、200、300、400、500 Gy剂量60Co-γ射线辐照处理,比较不同处理对火龙果种子萌发、根长及出苗的影响。结果表明,不同剂量60Co-γ射线辐照对火龙果种子的萌发和生长均有不同程度的影响,辐照剂量为25~100 Gy时60Co-γ射线可以促进种子萌发和生长。随着剂量的增大,辐照对于种子的萌发率、出苗率和根长抑制明显,剂量与之呈负相关。100 Gy处理的种子萌发率和出苗率最高,200~500 Gy时种子萌芽生长受抑制;200 Gy处理的出苗率均极显著比对照低。     

碧玉兰试管植株辐射诱变初探

本文论及60Co-γ射线作为诱变剂对碧玉兰组培苗辐照诱变育种的反应。试验表明:碧玉兰组培苗的半致死剂量为28.88Gy;在0~70Gy的范围内,碧玉兰的死亡率随着剂量的增加而增加,增殖率与变异率呈负相关。     

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.     

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.     

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.     

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.     

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.     

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.     

瓜叶绿素降解关键酶基因PPH和PAO cDNA片段的克隆与表达初步分析

 以西双版纳黄瓜和‘华黄5号’黄瓜叶片为试验材料,研究了衰老过程中两种黄瓜叶片叶绿素含量变化及脱镁叶绿素脱镁叶绿酸水解酶基因PPH和脱镁叶绿酸a加氧酶基因PAO的表达。结果表明：随着叶片衰老,叶绿素a和叶绿素b含量显著降低,叶绿素a与叶绿素b的比值在0.5左右,推测叶绿素b的含量可能对黄瓜叶片保绿起到重要作用。荧光定量RT-PCR分析结果显示：PPH和PAO在西双版纳黄瓜叶片生长35 d时表达量最高,分别为5.50和1.86;PPH在‘华黄5号’叶片35 d时表达量最高,为7.14,而PAO在35和45 d表达量都很高,分别为3.90和3.91;PPH和PAO在西双版纳黄瓜叶片中的表达量低于在‘华黄5号’中。     

Effects of simvastatin on PDGF-BB and serum-induced proliferation of vascular smooth muscle cells and on the expression of tumor suppressor gene PTEN

AIM:To observe the effect of simvastatin on the proliferation of vascular smooth muscle cells(VSMCs) induced by serum and growth factor PDGF-BB and the effect of simvastatin on the expression of PTEN,a important regulator of G₁/S cell cycle transition. METHODS:The DNA synthesis was determined by [³H]-TdR incorporation, cell cycle was examined with flow cytometry, the protein level of PTEN was measured by Western blot method. RESULTS: (1)Simvastatin inhibited [³H]-TdR incorporation in a dose dependent manner. (2) Flow cytometric DNA analysis revealed that simvastatin induced significantly enhancement of G₀/G₁ phase and decrease in S phase VSMCs.(3)Simvastatin increased protein level of PTEN and mevalonate, a metabolite of HMG-COA, reversed the effect of simvastatin on PTEN protein expression. CONCLUSION:Simvastatin may inhibit proliferation of VSMCs and retarded cell cycle in G₀/G₁ phase by increasing PTEN expression through inhibiting synthesis of mevalonate.