高温胁迫下铁炮百合幼苗形态及生理反应的初步研究

 对离体扩繁的铁炮百合‘Snow Queen’幼苗进行不同时间、不同高温( 35℃/30℃、37℃/32℃、39℃/34℃) 处理, 测定了不同处理对幼苗外观形态和叶片中游离脯氨酸(pro) 、丙二醛(MDA) 、可溶性蛋白质含量和相对电导率。结果表明, 铁炮百合幼苗在37℃/32℃高温处理下, pro含量、MDA含量和相对电导率明显上升, 且3种指标之间具有显著相关性, 可以作为耐热性鉴定指标。37℃/32℃处理下,幼苗外观形态与生理指标变化基本一致, 能反应出幼苗耐热性。35℃/30℃、39℃/34℃处理下各指标间不具显著相关性。     

Effects of light quantum and hematoporphyrin therapy on the growth of tumor in rats

AIM:To study the effect of photodynamic therapy on the growth of tumor in rats.METHODS:W256 tumor cells were implanted in 40 rats by subcutaneous vaccination at groin.Then,the rats were treated by photodynamic therapy (PDT).Total saperoxides dismutase (T-SOD) and malondialdehyde (MDA) in plasma,tumor tissue and liver were detected.RESULTS:(1) The growth of tumor was significantly slow after the rats were transfused blood with ultraviolet radiation,with hematoporphyrin or with both ultraviolet radiation and hematoporphyrin (P<0.05,P＜0.01).(2) The activity of SOD was obviously increased and the contents of MDA were decreased in plasma while the growth of tumor was significantly slow in the ultraviolet radiation group (P<0.05,P＜0.01).However,the activity of T-SOD was weakened and the contents of MDA were increased in hematoporphyrin group (P<0.01) and ultraviolet radiation combined with hematoporphyrin group (P<0.01).CONCLUSIONS:The results indicate that the growth of tumor is inhibited by means of transfusion blood with ultraviolet radiation of hematoporphyrin.The most remarkable inhibitory effect is in ultraviolet radiation and hematoporphyrin group.The generation of singlet oxygen by PDT may be one of the mechanisms of killing tumor cells.     

Influence of subacute and subchronic treatment of abcisic acid and gibberellic acid on serum marker enzymes and erythrocyte and tissue antioxidant defense systems and lipid peroxidation in rats

This study describes the subacute and subchronic effects of two plant growth regulators (PGRs) [abcisic acid (ABA) and gibberellic acid (GA₃)] on serum marker enzymes [aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine phosphokinase (CPK) and lactate dehydrogenase (LDH), γ-glutamil transpeptidase (GGT)], antioxidant defense systems [reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione-S-transferase (GST) and catalase (CAT)] and lipid peroxidation level (Malondialdehyde = MDA) in various tissues of rats. Rats (Sprague-Dawley albino) were exposed to 75 ppm (parts per million) of ABA and GA₃. Seventy-five parts per million of PGRs as drinking water was administered orally ad libitum for 25 and 50 days continuously. The PGRs treatments caused different effect on the serum marker enzymes, antioxidant defense systems and the content of MDA in comparison to those of control rats. Results show that ABA caused a significant decrease in serum LDH and CPK activity with both periods. Also, GA₃ significantly decreased serum AST, CPK, and LDH activity with subacute and decreased serum ALT, CPK, LDH, and GGT treated with subchronic periods. The lipid peroxidation end product MDA significantly increased in the erythrocyte, liver, brain, and muscle of rats treated with both the period of GA₃ without significantly change in the erythrocyte and muscle of rats treated with the subacute period of ABA. The GSH levels were significantly depleted in the erythrocyte and brain of rats treated with both the period of GA₃ without any change in the erythrocyte, liver, brain, and muscle of rats treated with both the period of ABA. Also GSH levels in the muscle significantly depleted with the subchronic period of GA₃. Antioxidant enzyme activities such as SOD significantly decreased in the erythrocyte, liver and brain tissues but increased in the muscle tissue of rats treated with both the periods of GA₃. Meanwhile, SOD significantly decreased in liver and brain, and increased in muscle of rats treated with both the period of ABA. While CAT significantly decreased in the all tissues of rats treated with both the period of GA₃, decreased in the liver and muscle of rats treated with both the periods of ABA too. On the other hand, the ancillary enzyme GPx and GR activity in the erythrocytes, liver, brain and muscle were either significantly depleted or not changed with two periods of PGRs. The drug metabolizing enzyme GST activity significantly decreased in the brain of rats treated with subacute period of PGRs but increased in the erythrocytes of rats treated with subacute period of GA₃. As a conclusion, ABA and GA₃ had significantly increased the activity of hepatic damage enzymes. Also the rats resisted to oxidative stress via antioxidant mechanism. However, the antioxidant mechanism could not prevent the increases in lipid peroxidation in rat’s tissues. These data, along with changes, suggest that PGRs produced substantial systemic organ toxicity in the erythrocyte, liver, brain, and muscle during the period of a 25-day subacute and 50-day subchronic exposure.     

Study of lung morphologic features and oxygen free radicals in experimental diabetic rats

AIM:To evaluate the changes of lung morphologic features and oxidative stress in experimental diabetic rats. METHODS: The pulmonary structure of alloxan-induced diabetic rats were quantitatively studied with stereological methods. Changes of ultrastructure, activities of superoxide dismutase (SOD) and contents of malondialdehyde(MDA) of diabetic lung and serum were observed. RESULTS: The volume proportion of alveolar air and mean linear intercept of diabetic rats decreased remarkably in comparison with controls while the volume proportion of alveolar wall, the surface density of alveolar, the numerical density of alveolic area, the numerical density of alveolar and specific surface of alveolar increased significantly. The major change of the type II pneumocyte of diabetic rats was dilation of the rough endoplasmic reticulum (RER). The other findings in diabetic rats had included the presence of thickened alveolar epithelial, pulmonary capillary basal laminae and blood- air barrier, the volume density, the surface density, the mean profile area and the mean perimeter of RER in type Ⅱ pneumocyte of diabetic rats increased remarkably. And the specific surface of RER was significantly lower as compared with controls. SOD activity decreased and MDA content increased significantly in serum of diabetic rats as compared with the control group. SOD activity in the diabetic lung was not different from that of the control lung. However, the content of MDA obviously increased in diabetic lung. CONCLUSION: The morphologic features and oxidative stress in early diabetic rats are abnormal thus the lung should be considered as one of the "target organ"in diabetes mellitus.     

棉花苗期叶片关键生理指标对涝渍胁迫的响应

利用盆栽棉花幼苗进行不同时长(3、6、9、12d)的淹水试验,观测棉花叶片的叶绿素组分(Chl)、叶色度(Rc)、叶绿素荧光动力学参数(F0、Fm)、丙二醛(MDA)、可溶性糖(DS)、脯氨酸(Pro)、超氧化物歧化酶(SOD)、过氧化物酶(POD)等关键生理指标,并与对照进行比较,分析其对涝渍灾害的响应.结果表明,淹水后的前3d棉苗叶片叶绿素水解速度最快,叶绿素荧光活性下降的峰值则出现在淹水后第6～9天.说明在田间管理上,应抓住时机在棉田淹水后的3d内尽快排涝降渍,避免植株光合能力受强烈抑制.涝渍胁迫发生后,叶片细胞内代谢平衡被打破,产生了如MDA含量增加和SOD活性下降等负面变化,不利于植株的恢复,同时也产生了如DS、Pro含量增加和POD活性提高等一系列正面变化,这对活性组织有保护作用.在淹水12d内,这些生理指标的变化速率呈现快-慢-快的规律,可用三次曲线来模拟其变化特点.     

不同铜源对存储期间大豆油脂氧化酸败的影响

本试验旨在模拟实际生产中8％ 仔猪预混料中油脂与微量元素的添加量,分析不同形式的铜对大豆油油脂氧化指标的影响.将五水硫酸铜、碱式氯化铜和甘氨酸铜3种微量元素原料与大豆油的比例均设定在8.74:1000,与大豆油混合后在高温条件下储放0、10、20、30、40、50、60 d,检测各处理组的酸价、碘价、过氧化值和丙二醛含...     

渗透胁迫下玉米幼苗离体叶片膜透性变化机理的研究

在４０％（Ｗ／Ｖ）ＰＥＧ的渗透胁迫下，玉米幼苗离体叶片膜透性在丙二醛（ＭＤＡ）含量未发生变化之前显著增大。而在２０％ＰＥＧ胁迫下ＭＤＡ含量先于膜透性增大。激动素不能降低４０％ＰＥＧ处理的膜透性，但可延迟２０％ＰＥＧ处理的ＭＤＡ含量的增加和膜透性的增大。说明不同强度水分胁迫下膜透性变化的机理不同，在高强度水分胁迫下可能是膜物理结构改变的结果，而在低强度的缓慢水分胁迫下则可能是自由基积累引起膜脂过氧化作用所致。     

南雄烟区主栽烤烟品种成熟期丙二醛含量变化规律研究

通过对南雄烟区不同烤烟品种成熟过程中活体、离体烟叶丙二醛含量及其变化规律分析,揭示不同烤烟品种烟叶的成熟度与丙二醛含量及其变化的规律相关性差异。结果表明:(1)大田状态下,上部烟叶,‘K326’丙二醛含量随时间呈"S"型变化,‘粤烟97’、‘粤烟98’丙二醛含量随时间呈类指数型变化,采收时MDA含量分别为21.35、18.75、20.59μmol/g;中部叶,3个烤烟品种均呈类指数型变化,采收时烟叶MDA含量为19.74、12.55、12.98μmol/g。(2)离体状态下,上部烟叶,‘K326’丙二醛含量随时间呈类指数型变化,‘粤烟97’和‘粤烟98’呈"S"型变化;中部烟叶,3个烤烟品种均呈"S"型变化。(3)离体烟叶MDA含量在短时间内达到大田状态下成熟采收时的含量水平,而离体后上、中部烟叶MDA含量均呈现"S"型变化趋势,当达到采收值时正好处于离体烟叶"S"型变化趋势的拐点,即离体烟叶MDA含量变化到达拐点之前与大田状态下MDA含量的变化趋势一致。研究表明不同烤烟品种在烤烟成熟过程中丙二醛含量及其变化规律可以指示其成熟度。     

Temporal modulation of oxidant and antioxidative responses in Brassica carinata during β-aminobutyric acid-induced resistance against Alternaria brassicae

A preinoculative foliar application of 5 mM BABA significantly inhibited the colonization of Alternaria brassicae on leaves of Brassica carinata susceptible cultivar car6. BABA treatment led to transient but significant increase in H₂O₂ level during early stages of pathogen colonization. A significant increase in superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol dependent peroxidase (GDP) contributed to inhibition of the oxidative stress in BABA treated plants in response to pathogen infection. In conclusion BABA treatment led to proper balance of oxidant & antioxidants suitable for expression of resistance resulting in curtail of pathogen ingress during early stages of colonization.     

三唑酮对提高植物抗逆性的作用

三唑酮即是在农业生产中广泛使用的杀菌剂,又是一种植物生长调节剂。当植物受到逆境胁迫时,一定浓度范围的三唑酮能延缓叶绿素含量和相对含水量的下降、抑制丙二醛(MDA)含量和膜相对透性的增加、提高逆某些抗氧化剂含量和有关抗氧化酶活性,从而提高植物的抗胁迫能力。根据有关资料综述了三唑酮对提高植物抗逆性方面的作用。