Influence of selenium on oxidoreductive enzymes activity in soil and in plants

The aim of this greenhouse experiment was the assessment of the influence of H₂SeO₃ at soil concentrations of 0.05, 0.15 and 0.45 mmol kg⁻¹, on the activity of selected oxidoreductive enzymes in wheat (Triticum aestivum). The wheat plants were grown in 2 dm³ pots filled with dust-silt black soil of pH 7.7. Applied H₂SeO₃ caused activation of plant nitrate reductase at all concentrations, but activation of plant polyphenol oxidase at only two lower concentrations. The highest concentration caused inhibition of polyphenol oxidase and peroxidase. Plant catalase activity decreased under the influence of 0.15 and 0.45 mmol kg⁻¹ concentration. After the final analysis Se was quantified in plants and soil. The amounts in plants were: control (unamended soil) 1.95 mg kg⁻¹; I dose (0.05 mmol kg⁻¹) 18.27 mg kg⁻¹; II dose (0.15 mmol kg⁻¹) 33.20 mg kg⁻¹ and III dose (0.45 mmol kg⁻¹) 38.37 mg kg⁻¹, in soil: 0.265 mg kg⁻¹; 3.61 mg kg⁻¹; 10.53 mg kg⁻¹; 30.53 mg kg⁻¹; respectively. Simultaneously, a laboratory experiment was performed, where the activity of soil catalase and peroxidase were tested after 1, 3, 7, 14, 28, 56, and 112 days after Se treatment. Peroxidase activity in soil decreased with increasing Se content, over the whole experiment. The lowest dose of Se caused activation a significant 10% increase in catalase activity, but the influence of others doses was unclear.     

包膜复合肥料对盆栽大豆土壤酶活性的影响

采用盆栽试验的方法,研究包膜复合肥对大豆不同生育期土壤酶活性的影响。结果表明,在试验条件下,由于包膜复合肥对养分的显著控释效果,它的施用对土壤脲酶、中性磷酸酶、过氧化氢酶和蔗糖酶活性的影响要好于普通肥料处理。     

植物体内过氧化氢酶的研究进展

对植物体内CATs的研究进行了简要概括,重点讨论了其生理功能。     

多元醇对油菜衰老的生理调控及增产作用探讨

 研究了不同时期喷施多元醇对甘蓝型油菜的生理效应及增产效果。结果表明：初花期喷施多元醇能显著提高油菜叶片叶绿素含量和光合速率，减少脂质过氧化产物丙二醛积累和乙烯释放量，使叶片超氧物歧化酶与过氧化氢酶活性下降变慢；多元醇能增强油菜根系活力，使植株稳健生长；多元醇还能改善油菜的经济性状，增加有效分枝数和每株角果数，初花期和盛花期喷施多元醇分别增产10.4%和7.2%，对油菜籽的品质无不良影响，对油菜生育期影响不大。     

多抗霉素对植烟土壤酶活性的影响

采用室内模拟方法,研究了3种不同浓度多抗霉素对植烟土壤中多酚氧化酶、脲酶和过氧化氢酶活性的影响。结果表明,多抗霉素对植烟土壤中多酚氧化酶活性的影响表现为"抑制-激活"的作用;对土壤中脲酶活性的影响表现出"抑制-激活-抑制"的作用;对过氧化氢酶具有激活效应,且各浓度的多抗霉素对过氧化氢酶的影响基本相同,表现为"激活-抑制"的作用。     

溴氰菊酯及代谢产物对土壤过氧化氢酶活性的影响

研究了溴氰菊酯及其代谢产物对土壤过氧化氢酶活性的影响。结果表明,不同浓度的溴氰菊酯对土壤过氧化氢酶活性的影响不同。当溴氰菊酯浓度较低(1、10μg/g)时,对过氧化氢酶活性的影响为先抑制后激活再恢复;当溴氰菊酯浓度较高(40、80μg/g)时,对过氧化氢酶活性的抑制作用明显,几乎没有激活;溴氰菊酯浓度越低,其对过氧化氢酶的激活作用越强;溴氰菊酯的代谢产物(水解和光解产物)对过氧化氢酶活性的影响小于溴氰菊酯原药。     

蝴蝶和蝗虫肠道共生菌次生代谢产物的分离

采用分光光度计法测定低温处理后椰心叶甲啮小蜂（Tetrastichus brontispae）成虫体内3种保护酶活性的变化。结果表明,椰心叶甲啮小蜂成蜂受到低温胁迫后体内CAT、POD和SOD分别在10 ℃和-2 ℃出现两个高峰,酶活性总体水平高于对照。-2 ℃时,3个处理时间的CAT、POD和SOD活性最高,其中,CAT、SOD活性差异性显著。由于各种酶的特性不同,它们对低温应激处理时间的反应亦不同,SOD在处理12 h时酶活性最高,而CAT与POD在24 h时酶活性最高。     

Induction of the Expressions of Antioxidant Enzymes by Luteinizing Hormone in the Bovine Corpus Luteum

Luteoprotective mechanisms of luteinizing hormone (LH) involved in the maintenance of bovine corpus luteum (CL) function have not been completely clarified. Since antioxidant enzymes are well documented as antiapoptotic factors in the CL of many mammals, we hypothesized that the luteoprotective action of LH is mediated by stimulating the local production and action of antioxidant enzymes. To test the above hypothesis, in the present study, we examined the mechanisms involved in the luteoprotective actions of LH. Cultured bovine luteal cells obtained from the CL at the mid-luteal stage (days 8–12 of the estrous cycle) were treated with LH (10 ng/ml), onapristone (OP; a specific progesterone receptor antagonist, 100 μM) and diethyldithiocarbamate [DETC; an inhibitor of superoxide dismutase (SOD), 100 μM] for 24 h. LH in combination with or without OP significantly increased the mRNA and protein expressions of manganese SOD (Mn-SOD) and catalase (CATA) and SOD activity. While LH alone significantly increased the mRNA and protein expressions of SOD containing copper and zinc (Cu,Zn-SOD), OP in combination with or without LH significantly decreased the mRNA and protein expressions of Cu,Zn-SOD. In addition, Cu,Zn-SOD, Mn-SOD and CATA mRNA expressions were higher at the mid luteal phase than the other luteal phases. LH in combination with DETC significantly decreased LH-increased cell viability. The overall results suggest that LH increases cell viability by LH-increased antioxidant enzymes, resulting in maintenance of CL function during the luteal phase in cattle.     

过氧化氢酶高产菌株EIM-70的鉴定及产酶培养基的优化

[目的]对过氧化氢酶高产菌株EIM-70进行鉴定,并对其产酶培养基进行优化。[方法]对EIM-70菌株进行形态学分析及16SrDNA序列的系统发育进化分析,以鉴定其所属菌种;在采用单因素试验确定EIM-70产过氧化氢酶的最适碳、氮源基础上,采用Plackett-Burman试验设计筛选出对产酶影响显著的因子,再利用最陡爬坡试验和响应面分析法确定最适产酶培养基配方。[结果]试验将EIM-70菌株鉴定为枯草芽孢杆菌(Bacillus subitilis);EIM-70的最适产酶培养基为:葡萄糖19.25 g/L、NaNO39.25 g/L、FeSO4.7H2O2.46×10-3g/L、MgSO4.7H2O 0.50 g/L、Na2HPO4.12H2O 9.25 g/L、KH2PO40.60 g/L、2°麦芽汁,优化后Bacillus subitilis EIM-70的液体发酵产过氧化氢酶的活力可达6 927.45 U/ml,比优化前提高1.87倍。[结论]该研究为过氧化氢酶的工业化生产奠定了基础。     

除草剂草甘膦对土壤过氧化氢酶活性的影响

研究了草甘膦对土壤过氧化氢酶活性的影响。结果表明:草甘瞵对土壤中过氧化氢酶的活性有明显的影响,随着浓度的升高,对过氧化氢酶活性抑制作用有所增强,草甘瞵对离体过氧化氢酶有一定的抑制作用。高浓度时对大棚土壤过氧化氢酶活性的抑制作用明显高于对农田土壤的抑制作用。实验结果表明:草甘瞵在农业生产实际用量下属于低毒或无实际危害的农药。