NaCl胁迫对番茄叶片光合特性及蔗糖代谢的影响

为了从碳水化合物生产及代谢的角度分析盐胁迫影响番茄产量和果实品质的原因,以番茄品种‘辽园多丽’为试材,研究不同浓度的NaCl胁迫处理对番茄光合特性及叶片中糖代谢的影响。结果表明:盐胁迫导致番茄叶片的净光合速率下降,NaCl浓度越大降低得越多;盐胁迫降低了番茄叶片的气孔导度、胞间CO2浓度和蒸腾速率,降低了番茄叶片的叶绿素a、b和总叶绿素含量,这种降低与NaCl浓度正相关。NaCl胁迫导致番茄叶片中果糖和葡萄糖大量积累,NaCl浓度越高积累得越多;NaCl胁迫降低了番茄叶片中的蔗糖和淀粉含量;NaCl胁迫后,番茄叶片中的转化酶活性以及蔗糖合成酶活性均有所提高,而且随着盐浓度增加而增大。说明NaCl胁迫破坏了番茄叶片的光合机能,降低了光合作用效率,而且盐浓度越大降低得越多;NaCl改变了番茄叶片中的糖代谢方向,显著增加了淀粉和蔗糖的分解,提高了叶片中的果糖和葡萄糖含量,而且这种影响随着盐浓度增加而增大。     

Effects of baicalin on CA46 cell xenografts in nude mice

AIM: To study the effects of baicalin on CA46 cell xenografts in nude mice. METHODS: The nude mice with CA46 cell xenografts were treated with drugs via intraperitoneal injection daily, and were divided into 5 groups: negative control group, 15 mg/kg baicalin group, 30 mg/kg baicalin group, 60 mg/kg baicalin group and 4 mg/kg etoposide (VP-16) positive control group. After 12-day treatment, the weight of CA46 cell xenografts stripped from some nude mice in the 5 groups was used to evaluate the effect of baicalin on xenograft growth in the nude mice. The apoptosis, necrosis and pathological changes of the xenograft cells were examined under light microscope and transmission electronic microscope respectively. The expression levels of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway-related proteins extracted from xenografts were determined by Western blotting. The other nude mice with CA46 cell xenografts in the 5 groups continued to be treated with the drugs until death in order to evaluate the effect of balcalin on survival time of the nude mice with CA46 cell xenografts. RESULTS: Baicalin remarkably inhibited the growth of CA46 cell xenografts, induced apoptosis and necrosis of xenograft cells, and reduced the protein expression of phospho-Akt (p-Akt), nuclear factor-kappa B (NF-κB), mammalian target of rapamycin (mTOR) and phospho-mTOR (p-mTOR) in the xenografts after 12-day treatment. Furthermore, baicalin prolonged the survival time of the nude mice with CA46 cell xenografts in a dose-dependent manner. CONCLUSION: Baicalin inhibits the growth and induces apoptosis of CA46 cell xenografts in the nude mice, and prolongs the survival time of the nude mice with CA46 cell xenografts through the mechanism of down-regulating PI3K/Akt/NF-κB and PI3K/Akt/ mTOR signaling pathways.     

BBTV两个株系DNA组分1的克隆及序列分析

 对在生物学特性特别是寄主范围上存在明显差异的NSP株系和NS株系的代表分离物(广州天河分离物和高州分离物)的DNA组分1进行了克隆和序列分析,结果表明:2个代表分离物的DNA组分1全序列、ORF及其编码的氨基酸序列的变异率分别为3.2%、3.1%和2.8%,从而进一步确证了可以用寄主范围来作上述2个株系的鉴定。此外,这2个株系的DNA组分1、ORF及其编码的氨基酸序列分别与肖火根等报道的中国(广东)分离物、以及亚洲组和南太平洋组各分离物进行比较,结果表明:NS株系与肖火根等报道的中国(广东)分离物的亲缘关系很密切;这2个株系与亚洲组各分离物的差异均较小,而与南太平洋组各分离物的差异均较大,它们应属亚洲组。     

苹果树腐烂病的发生与防治

<正>苹果树腐烂病在陕西省吴堡县山地果园发生普遍,危害严重。据对30hm22000株20年生苹果树调查,发病株率达62.5%,其中整株死亡的达24.2%。对此,经过多年的发病观察和防治试验,取得了经济、有     

腾冲过路黄的生长动态观察研究

对腾冲过路黄的物候期进行观察,并绘制出物候图谱。测定其各器官生长动态,结果显示：腾冲过路黄的根系集中分布层深度为10～26 cm,其茎含水量平均为82.02％,叶含水量平均为79.87％,根含水量平均为85.68％。采用相关分析及建立生物量一元线性回归方程,茎、叶、根的生物量（干重Y）可分别用Y=0.0213X4.3369、Y=0.0565X3.9657、Y=0.0382X3.517来推测。     

紫花苜蓿叶片对硒胁迫的生理响应研究

以紫花苜蓿"大叶苜蓿""维多利亚""阿尔冈金"为试材,采用土培法,研究了硒胁迫对3种紫花苜蓿叶片酶促防御系统的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)和抗坏血酸过氧化物酶(APX)活性及丙二醛(MDA)、可溶性蛋白质含量的影响。结果表明:在100μmol·L-1Se时,硒胁迫显著提高了3种紫花苜蓿叶片SOD、APX、POD、CAT活性和可溶性蛋白质含量。Se为900μmol·L-1时,SOD、APX活性和可溶性蛋白质、MDA含量显著增加,而CAT、POD活性显著降低。不同品种间抗氧化酶活性相比,"大叶苜蓿"抗氧化酶SOD、APX、POD、CAT活性显著高于其它2个苜蓿品种,且差异显著。综合评价表明,"大叶苜蓿"的抗氧化能力最强,其次为"阿尔冈金","维多利亚"苜蓿的抗氧化能力最差。     

红托鹅膏生态环境研究

以武定狮山为样点,对红托鹅膏的生境进行了初步研究。结果表明,红托鹅膏主要生长于滇青冈、滇石栎等阔叶林或针（云南松）阔混交林中,其生长的土表层疏松、透气、潮湿,具有厚4 cm~9 cm的腐叶层,有稀薄的阳光透入,土层有机质含量高,矿物质养分丰富,土壤容重较小,偏微酸性（pH5.4~5.7）。子实体分化发育较适宜的温度为19℃~21℃,空气湿度为75%~86%,土壤含水量为38%~50%,并每天保证1 300 lx~2 000 lx的光照2 h~5 h,200 lx~900 lx的弱光6 h~9 h。     

苜蓿冰结构蛋白抗冻活性及功能性研究

以"肇东"紫花苜蓿干草为原料,采用磷酸盐缓冲溶液法提取苜蓿冰结构蛋白,研究了温度、pH值、NaCl及蔗糖浓度不同提取因素对苜蓿冰结构蛋白功能的影响。结果表明:苜蓿冰结构蛋白溶液的冰晶体积小、数量多、形状不规则,具有很好的抗冻活性;对苜蓿冰洁构蛋白的功能性进行测定,随着溶液pH值的增加,其溶解指数、持水性、乳化性和乳化稳定性、起泡性与泡沫稳定性都呈现出逐渐增大的趋势;随着NaCl浓度的增加,其起泡性和泡沫稳定性先增加后降低、乳化性和乳化稳定性呈现下降趋势;随着蔗糖浓度的增加,其蛋白起泡性和泡沫稳定性逐渐增加,而乳化性和乳化稳定性影响不大。     

Relationship between Th1/Th2 balance and CD28/CTLA-4 expression on peripheral blood T cells in patients with systemic lupus erythematosus

AIM: To investigate the pattern of Th1/Th2 balance in systemic lupus erythematosus(SLE) patients and the relationship between CD28/CTLA-4(cytotoxic T-lymphocyte antigen-4) molecule expression and Th1/Th2 balance.METHODS: Eighteen SLE patients met the ARA 1997 updated SLE criteria were selected in the study. According to Bombardier's SLEDAI criteria, all patients were classified into two groups: active group(12 cases) and static group(6 cases). Fourteen normal individuals, matched for age and sex of the patients, served as controls. The peripheral blood mononuclear cells(PBMCs) were isolated by density gradient centrifugation and cultured in RPMI-1640 culture medium. After treated with PMA(5 μg/L) and ionomycin(500 μg/L) for 72 h, the PBMCs were collected, the contents of IFN-γ and IL-10 in the supernatant of cultured PBMCs were detected using enzyme linked immunosorbent assay(ELISA). The expression of CD28 and CTLA-4 molecules on T cells were detected by flow cytometric technique with double staining by FITC or PE labeled monoclonal antibodies. RESULTS: The level of IL-10 was higher in the PBMCs of active and static SLE patients(351.29 ng/L±153.31 ng/L and 319.37 ng/L±153.39 ng/L) than that in controls(254.48 ng/L±120.69 ng/L), but the difference did not reach statistical significance(P>0.05). The level of IFN-γ was significantly lower in the PBMCs of active SLE patients(25.76 ng/L±16.09 ng/L) than that in controls(50.71 ng/L±27.92 ng/L, P＜0.05). The ratio of IL-10/IFN-γ was significantly higher in active SLE patients(18.74±13.77) than that in controls(6.66±4.95, P<0.05). Either before or after culture, the expression of CD28 molecule on CD3⁺and CD8⁺ T cells from all SLE patients was not remarkably different from that in the cells of controls. Before culture, the expression of CTLA-4 molecule on CD3⁺T cells of active SLE patients(0.79%+0.37%) was significantly lower than that in the cells of controls(1.31%+0.61%, P<0.05). After culture, the expression of CTLA-4 molecule on CD3⁺ T cells of SLE patients was still lower than that in the cells of normal controls without statistical significance(P＞0.05).The expression level of CD28 molecule on CD3⁺ or CD8⁺ T cells in active SLE patients and controls was not correlated with the levels of IFN-γ and IL-10 in the supernatants(P＞0.05). The level of CTLA-4 molecule expression on CD3⁺ T cells of active SLE patients was positively correlated with IFN-γ level(r=0.681, P<0.05), while was negatively correlated with IL-10 levels(r=-0.624,P＜0.05) and the ratio of IL-10/IFN-γ(r=-0.738, P<0.01). The level of CTLA-4 molecule expression on CD3⁺ or CD8⁺ T cells of controls showed no correlation with IFN-γ levels, while showed negative correlations with IL-10 level(r=-0.587, P<0.05; r=-0.563, P<0.05, respectively).CONCLUSION: There is a bias in the differentiation of Th0 cells towards Th2 in SLE patients. CTLA-4 probably plays an important role in this mechanism through suppressing the signal transmitted by CD28.     

新疆野生樱桃李SSR体系的建立及应用

为建立适宜新疆野生樱桃李的SSR分子标记技术体系,通过对PCR反应程序、反应体系(DNA模板量、引物浓度、Mg2+浓度、dNTP浓度、Taq酶用量)以及退火温度进行了探索,建立了适宜野生樱桃李的SSR-PCR反应体系。结果表明:在25μL反应体系中,Mg2+1.0 mmol/L、引物0.5μmol/L、dNTPs 0.20 mmol/L、TaqDNA聚合酶1.0 U、模板DNA 30 ng、退火温度为60℃。SSR扩增程序:94℃预变性5 min,35个循环(94℃30 s,60℃1 min,72℃1 min),72℃延伸10 min,可筛选出稳定性好、多态性高的SSR引物。