粤西1号芒果成熟阶段的蔗糖代谢

以粤西1号为试材研究了芒果果实成熟阶段淀粉、葡萄糖、果糖和蔗糖的含量以及蔗糖代谢相关酶-酸性转化酶(AI)、中性转化酶(NI)、蔗糖合成酶(SS)和蔗糖磷酸合成酶(SPS)的活性变化.结果表明:采收前淀粉含量逐渐减少,采收后快速减少;葡萄糖含量采收后呈先增后减的趋势,果糖含量采收前缓慢增加,采收后开始迅速增加,蔗糖变化与果糖变化趋势一致,完熟时含量最多的糖为蔗糖(62.55 mg,g),果糖次之(44.45 mg/g),葡萄糖最少(2.87mg/g).AI、NI、SS、SPS在采收前活性差别不大,在后熟阶段,AI、SS、SPS活性显著增加,且SPS活性达到最高值.粤西1号糖代谢以积累蔗糖为主,2种酶SPS和SS起关键作用.     

光照强度昼变化对烟叶蔗糖转化酶和蛋白酶活性的影响

为探索光照强度昼变化对植物叶片水解酶活性的影响,以烟草叶片为材料,对蔗糖转化酶和可溶性糖含量,蛋白酶活性和蛋白质、游离氨基酸含量与光照强度昼变化之间的关系进行研究.结果表明,光照强度的昼变化对蔗糖转化酶和蛋白酶活性有较大影响,随光照强度增强,蔗糖转化酶活性在11:00达到最高点3.933 mg/(g.h),之后开始逐步下降;蛋白酶活性在午后大幅度上升,17:00达到最大值125.33 mg/(g.h),之后迅速下降.对烟叶蔗糖转化酶和蛋白酶活性进行分析时,前者应在11:00左右取样测定;后者应在15:00之后取样测定.     

甘薯细胞壁蔗糖转化酶基因IbCWIN家族成员鉴定及表达分析

甘薯是重要的粮食、饲料、工业原料作物和新型的生物能源作物,细胞壁蔗糖转化酶是植物源、库组织蔗糖代谢的关键酶,但关于甘薯细胞壁蔗糖转化酶基因IbCWIN家族成员的研究尚未见报道。本研究测定供试品种不同组织部位的蔗糖淀粉含量,利用生物信息学方法对IbCWIN基因家族的理化性质、保守结构域、系统进化关系、启动子作用元件、组织特异性表达模式进行分析。结果表明,甘薯茎中蔗糖含量最高,须根和叶次之,块根最低;块根淀粉含量最高,极显著高于其他部位。甘薯中含有10个IbCWIN基因,编码氨基酸442～1115个,蛋白质分子量范围49.56～124.44kD,等电点为5.0～9.1。分布在8条染色体上,都含有Glyco₃2保守结构域及相同或相似的保守基序motif,属于糖基水解酶基因家族GH32。IbCWIN与木薯MeCWINV同源性高, IbCWIN基因家族启动子区域含有多种类型的顺式作用元件。qRT-PCR结果表明,IbCWIN基因家族在甘薯不同组织中均有表达且有多种表达模式,其中IbCWIN2和IbCWIN9在块根中表达量显著高于其他组织部位。本研究为下一步探索甘薯IbCWI...     

单嘧磺隆对土壤呼吸脱氢酶和转化酶活性的影响

通过室内培养研究了不同浓度单嘧磺隆对土壤呼吸强度和土壤脱氢酶活性、转化酶活性的影响。结果表明,单嘧磺隆的影响随单嘧磺隆浓度和作用时间的不同而异,田间推荐剂量下单嘧磺隆对土壤呼吸强度、土壤脱氢酶活性和转化酶活性没有显著持续不良影响。低浓度单嘧磺隆(<0.8μg·g-1)在试验初期轻微刺激土壤微生物的活性,随培养时间延长刺激作用消失;高浓度单嘧磺隆(>4.0μg·g-1)在试验初期显著抑制土壤微生物活性,对土壤呼吸强度的抑制率最高为26.55%,培养12d以后抑制作用消失,土壤呼吸强度恢复到对照水平。极高浓度单嘧磺隆(25μg·g-1)显著抑制土壤转化酶和脱氢酶活性,在25d试验周期内抑制率分别为5.53%～51.72%和16.06%～21.76%。田间推荐剂量单嘧磺隆(0.025μg·g-1)对土壤转化酶有短暂的抑制作用,最高抑制率为20.23%,对脱氢酶没有明显影响。0.25和2.5μg·g-1单嘧磺隆在试验不同时期对土壤酶活性有轻微刺激作用或抑制作用。第8d时,单嘧磺隆显著抑制土壤转化酶活性,且抑制作用和单嘧磺隆浓度表现出正相关(r=0.95),试验结束时单嘧磺隆的影响减弱。     

外源生长素对番茄果实蔗糖代谢关键酶活性及基因表达的影响

以普通栽培型番茄辽园多丽为试验材料,研究了花期施用PCPA对发育过程中的番茄果实糖含量变化、蔗糖代谢关键酶活性及可溶性酸性转化酶基因表达的影响.结果表明,随着番茄果实的发育,可溶性酸性转化酶的活性和酶基因的表达均增强,果糖和葡萄糖的含量也呈递增的趋势,成熟时含量最高.PCPA处理在果实发育的成熟期提高了酸性转化酶的活性,促进了可溶性酸性转化酶基因的表达,增加了果糖和葡萄糖的含量.     

Antioxidative Enzymes and Sucrose Synthase Contribute to Cold Stress Tolerance in Chickpea

Chickpea is sensitive to low temperature (<10°C) during its reproductive stage. Low temperature adversely affects the development of pods and seeds. This study was undertaken to investigate the role of sucrose metabolizing enzymes in seed development and potential of antioxidative enzymes in protecting seeds and podwalls from the deleterious effects of cold stress in advanced cold tolerant chickpea breeding lines. Healthy pod set was observed in these tolerant lines in the end of December where as low temperature susceptible PBG-1 did not flower. Two lines ICCV 96029 and ICCV 96030 showed susceptible characters such as reduced flowering, blackened and shrivelled seeds and yellowish pods in comparison to other cold stress tolerant lines due to sudden dip of temperature (<1 °C) during the first week of January. These two lines were, therefore, treated as susceptible checks in comparison to other tolerant lines. A significantly higher activity and specific activity of sucrose synthase was observed in seeds of most of the cold tolerant lines in comparison with ICCV 96029 and ICCV 96030, thereby providing sugars as well as sugar nucleotides for their growth and starch synthesis during unfavourable low temperature. The developing seeds and podwalls of tolerant genotypes had higher activities of antioxidant enzymes, i.e. catalase, ascorbate peroxidase and glutahione reductase in comparison with ICCV 96029 and ICCV 96030. It appears that the higher activities of antioxidant enzymes in podwall protect the developing seeds from cold stress.     

The use of photometric test kits for investigations of soil enzyme activities

The objective was to test the applicability of different photometric test kits for the determination of potential and actual nitrification and the activities of urease, invertase, and cellobiase in soil. Three water affected grassland sites, influenced by the maritime climate were investigated. The results obtained by the test kits and by standard methods were similar. Soil organic matter content was found as most important factor determining the enzyme activities on these three grassland sites with similar pH‐values. At the site with the largest soil organic matter content the highest activities for urease, invertase, and cellobiase were found. However, this was not true for the nitrification rates.     

不同处理对生物有机无机复合肥活菌数和酶活性的影响

采用室内培养分析测试方法,研究了不同处理对生物有机无机复合肥的有效活菌总数和酶活性变化的影响。结果表明,(1)添加低量(3%纯氮)尿素对肥料有效活菌总数未产生显著不良影响,达到1.54×109个·g-1,是不加尿素处理的72.30%。180d时有效活菌总数只下降了25.35%,不影响肥料质量。添加高量(6%和9%纯氮)尿素,有效活菌总数明显偏低,仅为5.25×105个·g-1和4.83×105个·g-1。(2)生物有机无机复合肥中蔗糖酶活性较高,脲酶活性处于中等水平,磷酸酶活性较低。添加低量尿素对蔗糖酶、磷酸酶活性有轻微抑制作用,但可提高脲酶活性。     

牡丹开花和衰老期间花瓣糖代谢的研究

 以牡丹( Paeonia suffruticosa) 品种‘洛阳红’和‘胡红’为材料, 研究了花开放和衰老过程中花瓣可溶性糖及其代谢相关酶活性的变化。结果表明: 伴随花瓣的迅速生长展开, 总可溶性糖呈现迅速增加的趋势, 特别是己糖(葡萄糖和果糖) 含量显著增加, 盛开后己糖水平达到最高, 而蔗糖含量呈现逐渐下降的变化。己糖和蔗糖降解指数(SDI) 与花枝质量呈现极显著的正相关; 花瓣酸性转化酶活性维持较高水平, 开花过程中活性逐渐升高, 开放后逐渐下降。经主成分回归分析, 可溶性糖的代谢依赖于酸性转化酶、中性转化酶、蔗糖合成酶和蔗糖磷酸合成酶的共同作用。结果提示, 牡丹花瓣中己糖的积累在花开放和衰老过程中起着重要作用。     

磁场处理对土壤蔗糖酶和淀粉酶活性的影响

本文较为系统地研究了不同磁处理对黑土、白浆土及棕壤的蔗糖酶和淀粉酶活性的影响。研究结果表明磁处理可提高这两种酶的活性，但适宜的磁场强度随土壤类型、土壤湿度（风干土及２０％含水量的湿土）及处理时间的不同而差别较大。磁处理对土壤蔗糖酶活性的影响大于淀粉酶，但对淀粉酶活性的影响有较好的规律性。蔗糖酶磁处理效果是风干土样＞２０％湿度土样，淀粉酶磁处理效果则是２０％湿度土样＞风干土。