石榴叶的功能活性及其开发利用

从石榴叶的活性成分、功能活性以及开发利用三方面对石榴叶进行了综述，同时对目前石榴叶研究存在的问题进行了总结与展望，以期为石榴叶的进一步研究与开发提供参考。     

GnRH并列体二聚体主动免疫对公兔性腺的影响

用GnRH并列体二聚体主动免疫公兔，观察了免疫对公兔性腺及体重的影响。结果表明，免疫不影响公兔体重的工，而使公兔睾丸重量降低，就纵长缩短，表明性腺有萎缩的趋势。     

干旱-低温交叉逆境下小麦活性氧清除系统的变化与交叉适应的关系

采用人工气候箱砂培的方法研究了干旱、低温交叉逆境下2个小麦品种活性氧清除系统的变化与交叉适应的关系.结果表明,经单一逆境(干旱或低温)处理后超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性和还原型谷胱甘肽(GSH)含量降低,过氧化物酶(POD)活性和抗坏血酸(AsA)含量有所升高,但总体表现出活性氧清除系统功能降低,质膜相对透性增大(膜系统受损).经2种逆境交叉处理后,保护酶活性及抗氧化剂含量均明显增高,质膜相对透性降低至接近正常水平.表明小麦幼苗对干旱和低温逆境存在着明显的交叉适应现象,经一种逆境处理后可提高对另一逆境的抗性.外施脱落酸(ABA)处理同样也能明显提高逆境下小麦活性氧清除系统的功能,增强对干旱和低温逆境的抗性.这些现象表明植物对不同逆境的适应存在着某些共同的生理基础,而这些生理基础与ABA有关.     

旁路氧化作用对嘧菌酯抑制辣椒炭疽菌孢子萌发和菌丝生长的影响

 研究表明,旁路氧化作用能够降低辣椒炭疽菌对嘧菌酯的敏感性。离体培养条件下,旁路氧化在辣椒炭疽菌野生菌株的孢子萌发中提供大于95倍生理功能的补偿作用;在菌丝生长中提供20~35倍的补偿作用。但在接种前用嘧菌酯处理辣椒,旁路氧化作用并不明显,嘧菌酯对辣椒炭疽病有良好的保护、治疗、铲除和抗产孢作用。用嘧菌酯处理过的病斑产生的分生孢子萌发活力和致病力下降。炭疽菌离体下的菌丝耗氧率测定表明,10μg/mL嘧菌酯处理1 h对菌丝呼吸耗氧有良好的抑制作用,其抑制效果随药剂浓度提高而略有增加。随处理时间延长,药剂对菌丝耗氧的抑制作用下降,但仍然抑制菌丝生长。研究证明:延长处理时间,呼吸作用对药剂的敏感性下降的机理不是因为旁路氧化途径增强,也不是因为基质中药剂效力的下降,而是存在其它机制。     

The effect of reflective foil and hail nets on the lighting,color and anthocyanins of ‘Fuji’ apple

We studied the influence of covering the orchard floor with reflective foil on photosynthetic active radiation (PAR) both under and outside hail nets, and the possibility that the reflective foil under the hail net compensates for light reduction in last month before harvest time. On the lower side of fruit in the canopy, the reflective foil increased PAR. The chromaticity value a^* showed a difference in the intensity of red coloration in the reflective foil and hail net treatments. Amounts of individual cyanidins were detected by using HPLC–MS. The accumulation of five individual anthocyanins (cyanidin-galactoside, three cyanidin-pentoses and cyanidin) was investigated during last month before harvest time. Concentrations of the main, cyanidin-galactoside in ‘Fuji’ apple increased before harvest time, and at harvest time the reflective foil caused an increase in all identified anthocyanins.     

Role of reactive oxygen species in 23-hydroxybetulinic acid-induced apoptosis in LoVo cells

AIM: To investigate the changes of reactive oxygen species (ROS) in apoptosis of LoVo cells induced by 23-hydroxybetulinic acid.METHODS: LoVo cells were treated with 23-hydroxybetulinic acid. The apoptotic morphological change was observed under the light microscope. Intracellular ROS production and the rate of apoptosis were detected by flow cytometry.RESULTS: LoVo cells improved apoptotic morphological changes treated with 23-hydroxybetulinic acid for 48 h. At concentrations of 25, 50, 100, 200 μmol/L of 23-hydroxybetulinic acid, the apoptotic rates of LoVo cells were (7.17±2.31)%, (15.60±4.02)%, (32.47±5.25)% and (52.71±5.93)%, respectively. The results indicated a certain concentration-dependent relationship. 23-hydroxybetulinic acid caused an increase in the ROS production, and the ROS levels were 2.83±0.80, 5.97±1.72, 12.53±2.57 and 16.73±4.58. Compared with the control group (2.13±0.32), the increase in ROS production in LoVo cells at the concentration of 100, 200 μmol/L of 23-hydroxybetulinic acid treatment was significant (P<0.05). CONCLUSION: 23-hydroxybetulinic acid induces LoVo cell apoptosis. The production of ROS may play a crucial role in the process of the LoVo cell apoptosis.     

Subsystems,flowpaths, and the spatial variability of nitrogen in a fluvial ecosystem

Nutrient dynamics in rivers affect biogeochemical fluxes from land to oceans and the atmosphere. Fluvial ecosystems are thus important environments for understanding spatial variability in nutrient concentrations. At the San Pedro River in semi-arid Arizona, USA, we investigated how variability in dissolved inorganic nitrogen (DIN) was regulated by subsystem type and hydrological flowpaths. The three subsystems we compared were the riparian zone, parafluvial (gravel bar) zone, and surface stream. DIN concentration was greater in the riparian zone than in the surface stream, suggesting that the riparian zone retains DIN and is a source of N for the surface stream. Parafluvial zones were too variable to generalize how they regulate DIN. Our hypothesis that subsystem type regulates DIN oxidation was too simple. The riparian and parafluvial zones host a mosaic of oxidizing and reducing conditions, as they exhibited highly variable ammonium to nitrate (NH₄⁺:NO₃⁻) ratios. Surface stream DIN was dominated by NO₃⁻. Along a subsurface flowpath in the riparian zone, we did not observe spatial covariation among the N forms and transformations involved in mineralization. We also compared spatial variability in solute concentrations between flowpaths and non-flowpath reference areas. Our mixed results suggest that spatial variability is regulated in part by flowpaths, but also by solute-specific processing length along a flowpath. To understand the distribution of N in fluvial ecosystems, subsystem type and flowpaths are readily discernable guides, but they should be coupled with other mechanistic factors such as biota and soil type.     

牦牛铜锌超氧化物歧化酶基因cDNA克隆测序及其分子进化研究

对牦牛Cu/Zn-SOD cDNA进行克隆测序。所扩增片段长度为842bp,编码区长度为459bp。扩增片段与奶牛Cu/Zn-SOD cDNA序列比较发现有16个碱基存在差异。通过与已知Cu/Zn-SOD cDNA序列的7个物种:人、猪、鼠、大鼠、奶牛以及马的cDNA序列的比较构建了分子进化系统树。对所得序列的ORF分析发现,牦牛Cu/Zn-SOD由152个氨基酸组成,并对氨基酸序列进行了比对分析。     

温度和辐射对一品红发育及主要品质指标的影响

 以辐热积(每日温度相对热效应×光合有效辐射, Photothermal p roduct, PTP) 为光温指标,通过不同扦插期的试验研究了温度和辐射与‘千禧’一品红发育和品质指标的定量关系, 明确了从短日至单苞期、单蕾期、多蕾期、开花期所需要的PTP。结果表明标准化株高净增量(株高净增量/扦插苗初始叶面积) 与PTP呈幂函数关系; 主干叶片净增数、侧枝叶片数、苞片数与PTP均呈线性关系; 冠高比与PTP呈负指数关系。     

红肉脐橙发育过程中抗氧化系统与活性氧的变化

 以红肉脐橙果肉为材料, 比较了不同时期谷胱甘肽(GSH) 、抗坏血酸(AsA) 含量及相关酶活性和活性氧(AOS) 产生速率的变化。结果表明: 果肉在整个发育过程中, 脱氢抗坏血酸还原酶(DHAR) 活性在很大程度上可以促进AsA积累, 两者呈显著的正相关( r = 0.870, P <0.05) , 并且与抗坏血酸过氧化物酶(AsA-POD) 活性在动态上彼此消长; 谷胱甘肽还原酶(GR) 的变化趋势与GSH相同,呈单峰型的变化, 两者的相关系数为r = 0.978 ( P < 0.01) ; AsA /DHAsA和GSH /GSSG比率在整个发育过程中呈下降的趋势, 而活性氧(H₂O₂ , O₂^·) 水平一直呈上升变化。