稗草(Echinochloa crusgalli)根型ppc基因对水稻的遗传转化及其对光合速率的调节效应

稗草(Echinochloa crusgalli)是稻田中的C4光合型杂草,为了探索稗草ppc基因(Eppc)对水稻遗传转化的可行性及其对光合速率的调节效应,首次将含有稗草根型磷酸烯醇式丙酮酸羧化酶(phosphoenolpyruvate carboxylase,PEPC)基因ppc c DNA的2个植物表达载体p Ubi-Eppc、p Rbc S-Eppc通过农杆菌介导法对水稻进行了遗传转化。对分化植株进行的PCR、RT-PCR、克隆测序和Western杂交等结果均表明稗草ppc基因已经整合到了水稻基因组中,并且在转录和翻译水平都得到了表达。转基因水稻PEPC活性和气体交换参数测定结果表明T0代多数植株的PEPC活性高于对照,最高达到了对照的5.85倍;T0代大多数转基因植株叶片的净光合速率(Pn)比对照提高了20.00%,最大地提高了47.16%,同时叶片水分利用效率(WUE)也得到增强;T6代大部分转化植株的PEPC活性及Pn仍保持高于对照,本研究表明C3根型ppc基因过量表达也可以提高水稻的Pn,且证明稗草PEPC对光合作用具有较强的调节作用。     

Genetic Variability of Rubisco in Tetraploid Wheats (Triticum turgidum)

Nineteen tetraploid wheats (Triticum turgidum), differing in their agronomical behaviour and geographic origins were grown in two experiments and analysed for the following physiological traits: soluble leaf protein content, rubisco content, initial and potential carboxylase activities of this enzyme as well as its relative content in percentage of protein, the specific activity of the enzyme and its activation state. The results show a high genetic variability for all studied traits and more particularly for the initial carboxylase activity. High phenotypic correlation was observed between the rubisco content and its potential activities, in the first experiment. Correlation between souble leaf protein and rubisco content was significant in 9 genotypes of the second experiment.     

田间条件下转玉米C4型PEPC基因小麦的光合生理特性

为了检验转PEPC基因小麦是否具有C₄光合生理特性,以转PEPC基因小麦和对照周麦19为试验材料,分别于抽穗期、开花期、花后第7天和花后第15天测定其单株旗叶的气体交换参数日变化,对净光合速率日变化进行单位日光合总量分析, 并且对净光合速率日变化与单株气孔导度、胞间CO₂浓度、蒸腾速率日变化的相关性进行了分析;在花后第15天测定其单株叶绿素荧光参数,并在成熟期调查了单株产量性状。与对照相比,转基因株系在4个测定时期的旗叶净光合速率明显提高,尤其在花后第15天,单位日光合总量较对照提高29.1%和23.3%,气孔导度和蒸腾速率均明显增加,胞间CO₂浓度降低;花后第15天12:00与8:00相比,转PEPC基因小麦的F_v/F_m、q_p、NPQ、Φ_PSII的变幅均小于对照;单茎重、千粒重、单穗重和收获指数较对照显著增加。以上结果表明,转PEPC基因小麦材料在田间条件下光合特性明显优于对照,且具有提高小麦产量水平的潜力。     

植物乙酰辅酶A羧化酶β亚基acc D在因研究进展

综述了乙酰辅酶A羧化酶及其催化域羧基转移酶(Carboxyltransferase,CT)的β亚基(β-CT)的分布和生理功能、β-CT编码基因accD的分子生物学特征及乙酰辅酶A羧化酶在脂肪酸代谢工程中的应用研究进展。     

芳氧苯氧基丙酸酯类除草剂的应用进展

芳氧苯氧基丙酸酯（简称APP）类除草剂是近二十年发展起来的活性很好的新型除草剂,用于防除一年或多年生禾本科杂草。本文主要综述了APP的发展历史、作用机理、主要品种以及应用研究进展。     

茶树叶片内核酮糖二磷酸羧化酶酶蛋白水平的研究

茶树叶片内核酮糖二磷酸羧化酶蛋白水平,随着新梢叶片的逐渐成熟而增加,当叶龄在33～48天,叶片完全成熟时,蛋白水平达最高值并持续稳定,以后随叶龄的进一步增大而呈下降趋势;叶位试验也表现出相同的变化规律,以芽下第4～6叶位叶中的蛋白水平为稳定最高;在年生育过程中,不同品种春梢叶在春、夏、秋三季中的蛋白水平均以夏季最低,但福鼎大白茶表现为春>秋,而龙井43与龙井长叶表现为秋>春;不同品种春、夏、秋三季新梢叶中的核酮糖二磷酸羧化酶蛋白水平差异,福鼎大白茶与政和大白茶表现为春>秋>夏的规律,龙井43、龙井长叶、迎霜、水古四品种则以秋季最高,春、夏差异不大.     

脐橙果实发育过程中有机酸合成代谢酶活性的变化

 以红桔砧10 年生罗伯逊脐橙为试材, 研究了果实发育过程中有机酸代谢相关酶活性的变化及其与有机酸积累的关系。结果表明: 在整个果实发育过程中, 柠檬酸合成酶(CS) 和磷酸烯醇式丙酮酸羧化酶(PEPC) 活性与有机酸含量呈极显著正相关。这不仅证明脐橙果实中存在通过CO₂ 固定合成有机酸的途径, 还说明CS、PEPC 是有机酸合成的关键酶, 抑制CS 的活性能降低果实中有机酸的生成量。     

Astragalus polysaccharide attenuates free fatty acid-induced toxicity by activating AMPK in C2C12 myoblasts

AIM: To examine the effects of Astragalus polysaccharide (APS) on the toxicity of free fatty acids (FFAs) in C2C12 myoblasts. METHODS: C2C12 cells were randomly divided into 5 groups: control group, APS group, 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR)group,FFAs group and FFAs+APS group. MTT assay was used to observe the viability of C2C12 cells. C2C12 cells pretreated with FFAs at concentration of 0.25 mmol/L for 24 h were exposed to APS at dose of 200 mg/L for 24 h. The expression of total AMP-activated protein kinase (AMPK), phosphorylated AMPK (p-AMPK) and phosphorylated acetyl-CoA carboxylase (p-ACC) was examined by Western blotting. The content of AMP and ATP was determined by HPLC. The structural changes of the mitochondria were examined by transmission electron microscopy. RESULTS: The results of MTT assay indicated that APS improved the viability of C2C12 cells pretreated with FFAs. In FFAs+APS group, the ratio of AMP/ATP was increased after treatment with APS. No difference of total AMPK expression in C2C12 cells between APS group and FFAs group was observed. However, the expression of p-AMPK and p-ACC increased in APS group as compared with FFAs group. The results of transmission electron microscopy indicated that APS improved the vacuolar degeneration of mitochondria resulted from treatment with FFAs in C2C12 cells. CONCLUSION: In C2C12 cells, APS attenuates FFA-induced lipotoxity via a mitochondria-and AMPK-dependent mechanism.     

抗精噁唑禾草灵耿氏硬草乙酰辅酶A羧化酶基因研究

为明确耿氏硬草抗性种群SD-23对乙酰辅酶A羧化酶(ACCase)抑制剂类除草剂的抗性水平及靶标抗性分子机理,采用整株水平测定法测定了SD-23种群对6种ACCase抑制剂类除草剂的抗性,扩增和比对了抗性和敏感种群间的ACCase基因序列,并测定了耿氏硬草种群SD-23对其他4种除草剂的敏感性。结果表明,SD-23种群对精噁唑禾草灵产生了高水平抗性,抗性倍数为12.7,对炔草酯和精吡氟禾草灵产生了低水平抗性,抗性倍数分别为5.2和4.5,对烯禾啶、烯草酮和唑啉草酯较敏感。与敏感种群SD-1相比,SD-23种群ACCase的CT区域第2096位甘氨酸突变为丙氨酸(Gly-2096-Ala);甲基二磺隆、啶磺草胺和异丙隆对抗性和敏感种群均有较好防效,其防效达86.7%以上,干重防效达77.4%以上。ACCase的Gly-2096-Ala突变第一次在耿氏硬草中被报道,该突变可能是导致SD-23种群对精噁唑禾草灵产生抗性的重要原因之一。