采后黄冠梨果实糖代谢及相关酶活性变化规律

以黄冠梨为试材,研究采后梨果实糖代谢及相关酶活性的变化规律。果实采后即贮于温度0℃、相对湿度85%～95% 的冷库中,分别测定贮藏过程(0～240d)中果实中葡萄糖、蔗糖、总可溶性固形物(TSS)和可滴定酸(TA)的含量以及酸性转化酶(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。结果表明：在采后贮藏期间,黄冠梨果实中葡萄糖含量与AI、NI 活性均呈先升后降的趋势,且AI 活性出现明显高峰,而蔗糖含量与SS、SPS 活性均逐渐降低。TA 和TSS 含量是果实风味的重要指标,随着贮藏期的延长,TA 含量逐渐下降,而TSS 含量呈升- 降- 升的趋势。果实中蔗糖代谢参与酶的净合成活性与果实中蔗糖的积累密切相关,在采后贮藏期间其活性逐渐降低。     

饼肥对烤烟碳水化合物代谢及酶活性的影响

通过饼肥配施用量盆栽试验,研究了K326中部叶在不同发育时期蔗糖代谢的相关酶即转化酶(Inv)、蔗糖合成酶(SS)、蔗糖磷酸合成酶(SPS)的活性变化和中上部叶碳水化合物含量的变化。结果表明:转化酶和蔗糖合成酶对烟草叶片生长发育的作用时期不同,即转化酶在烟草叶片发育中期,蔗糖合成酶在叶片发育后期。在云南玉溪烟区砂红壤中以配施30g饼肥的处理更有利于烟叶中碳水化合物的积累。随着饼肥用量的增加,中、上部叶碳水化合物含量明显小于纯化肥的处理。     

不同贮藏温度条件下菜用大豆蔗糖代谢与相关酶活性变化

以‘新大粒1号’菜用大豆为试材,研究不同贮藏温度（1、5、10、20 ℃）条件下菜用大豆蔗糖代谢及相关酶活性的变化情况。结果表明,贮藏期间菜用大豆蔗糖、果糖及葡萄糖含量均呈整体下降趋势,1 ℃有效控制了蔗糖降解;酸性转化酶（AI）活性在第1天达到峰值后逐渐下降,不受贮藏温度影响;20 ℃条件下中性转化酶（NI）活性持续增加,至第4天达到最大值,其他温度组变化差异不显著（P＞0.05）;蔗糖合成酶（SS）活性略有降低后快速升高,至第4天达到峰值后逐渐下降;蔗糖磷酸合成酶（SPS）活性呈整体下降趋势,与蔗糖含量呈极显著正相关（P＜0.01）,与果糖含量呈显著正相关（P＜0.05）,其他酶活性与糖含量之间均无显著相关性（P＞0.05）。这表明SPS可能与‘新大粒1号’菜用大豆中蔗糖降解密切相关。     

甜菜氮营养对蔗糖积累转化及有关酶活性的调节

试验表明，甜菜块根中蔗糖含成酶（ＳＳ）活性和蔗糖磷酸合成酶（ＳＰＳ）活性高于叶片，随植株氮营养增加，可溶性蛋白含量增加，ＳＳ活性较ＳＰＳ活性提高得更快些，叶片中转化酶活性与氮素供应量呈显著正相关，导致块根，叶片蔗糖和己糖含量下降，叶片转化酶活性是ＳＳ活性的１７０倍左右，转化酶在蔗糖降解中起关键作用，表明氮营养通过影响蔗糖的合成与降解过程，调节蔗糖的实际积累量。放线菌素Ｄ对可溶性蛋白质含量，ＳＳ活性     

套袋对清见橘橙果实蔗糖代谢的影响

研究6 种果袋对清见橘橙果实可溶性糖含量及蔗糖代谢关键酶活性的影响。结果表明：不同果袋对清见橘橙果实可溶性糖含量的影响不同,单层果袋显著提高了果实的可溶性糖含量。果实成熟时,套白色单层无纺布袋的果实蔗糖含量最高,套黄色单层袋和白色单层袋的果实果糖含量均最高,套白色单层袋的果实葡萄糖含量最高。单层果袋提高了果实中性转化酶（NI）、蔗糖合酶（SS）和蔗糖磷酸合酶（SPS）的活性,以无纺布袋最为明显,而双层果袋对NI、SS、SPS活性的影响在多数测定点差异不显著。酸性转化酶（AI）活性随着果实的成熟而降低,套袋对AI活性的影响不显著。综上可知,单层果袋通过提高NI、SS、SPS的活性来提高糖含量,因此清见橘橙宜选择具有一定透光率且色泽浅的单层果袋。     

1-MCP联合乙烯吸附剂处理对黄桃果实冷害与糖代谢的影响

冷害是黄桃果实低温贮藏产生的一种生理性病害,本文选用1-甲基环丙烯(1-MCP)与乙烯吸附剂(EA)联合处理黄桃,研究1-MCP-EA和1-MCP对其果实冷害(CI)与糖代谢的影响。将黄桃在4 ℃下贮藏28 d,与对照和1-MCP相比,1-MCP-EA处理能够更好地维持果实硬度和可溶性固形物(soluble solid content,SSC)含量,减轻冷害褐变。黄桃果实糖含量与蔗糖代谢相关酶活研究表明,1-MCP单独处理和1-MCP-EA联合处理均能减少蔗糖含量的下降以及果糖与葡萄糖含量的上升,抑制酸性转化酶(AI)与中性转化酶(NI)活性的升高。1-MCP-EA处理可有效抑制黄桃果实的蔗糖合成酶(SS)活性上升和蔗糖单磷酸合成酶(SPS)活性下降。结论:1-MCP-EA处理抑制黄桃冷害效果最好,营养品质保持程度最佳。     

1-MCP处理对不同期采收的阿克苏富士苹果在采后贮藏期糖代谢的影响

以阿克苏富士苹果为试材,通过测定在贮藏过程中(0~150d),果实蔗糖、葡萄糖、果糖和山梨醇含量,以及蔗糖磷酸合成酶(SPS)、蔗糖合成酶(SS-S、SS-C)、酸性转化酶(AI)、中性转化酶(NI)和山梨醇脱氢酶(SDH)的活性,研究采后苹果果实糖代谢及相关酶活性的变化规律并分析了1-MCP处理对它们的影响。结果表明:在采后贮藏期间1-MCP处理在一定程度上抑制了贮藏过程中富士苹果果实蔗糖、葡萄糖、果糖和山梨醇含量的增加,且对不同采收期果实酶活性的影响效果不同,果实中蔗糖、山梨醇含量以及SDH活性呈下降趋势,果糖含量、葡萄糖含量、与SPS、SS-S活性呈先下降后上升趋势,AI与NI在贮藏过程中出现明显峰值,且1-MCP处理可以显著提高这一峰值。     

甘薯块根碳水化合物合成与积累动态特性研究

以不同干物质类型的甘薯品种绵粉1号、南薯88和商丘52-7为材料,研究了甘薯块根形成与膨大期间碳水化合物积累与淀粉合成相关酶活性的动态变化及其相互关系。结果表明,作为品种的固有特征,干物质含量或淀粉含量的差异主要决定于品种的遗传特性。对于中高干率品种而言,淀粉在生育中后期积累较快。磷酸蔗糖合成酶(SPS)活性与品种间淀粉积累量一致,中等干物质品种(南薯88)中后期的蔗糖合成酶(SS)活性较高,淀粉积累量也最多,SPS和SS对淀粉合成与积累具有促进作用,ADPG焦磷酸化酶有随气温降低而活性下降的趋势。此外不同品种均表现出甘薯块根干物质含量与可溶性糖含量、淀粉产量与可溶性糖含量呈极显著的负相关关系。     

甜菜糖代谢中氮营养对酶活性的影响

甜菜种于控制环境室,用7.5、15和30mN硝酸盐溶液作灌水,测定五个甜菜遗传型叶子的中性转化酶(NI)和酸性转化酶(AI)及蔗糖合成酶(SS)的转化活性。结果指出,酸性转化酶高于中性和蔗糖合成酶。从光合作用的扒制看,对蔗糖合成酶的转化活性ADP好像是较好的酶作用基质。就硝酸盐浓度看,中等氮量得到最大的酸性酶转化活性和中性转化酶活性,但无统计分析上的差异。相反,在比较的品种之间,酶的活性差异明显。     

不同形态氮素对甜菜蔗糖合成酶分解活性的影响

在不同施肥水平下，利用桶栽试验研究了硝态氮和铵态氮对甜菜体内蔗糖合成酶分解活性的影响，并分析了不同处理甜菜块根产量与含糖率的变化，初步探讨了氮素营养与甜菜蔗糖合成酶活性以及与产量、含糖的关系。结果表明，不同形态氮素及其不同施肥水平对甜菜体内的蔗酶合成酶活性影响不同，在同一施氮水平上，铵态氮处理的甜菜蔗糖合成酶的活性高于硝态氮处理的甜菜蔗糖合酶的活性，而施用同一形态氮素时，蔗糖合成成酶活性随硝态氮施量的增加而增加，根产量也表现相似变化，但在铵态氮条件下，蔗糖合成酶的分解活性及其甜菜含糖率的变化不尽相同。     

The Effects of Harvest Maturity on Storage Quality and Sucrose-Metabolizing Enzymes During Banana Ripening

Mature green “Baxi” banana (Musa spp. AAA Group, Cavendish) fruits were harvested at 60% and 80% maturity stages. In order to evaluate the effects of harvesting at different maturity stages on storage quality and changes in sucrose-metabolizing enzymes, fruit firmness, disease index, contents of starch, and total soluble sugars were determined, and enzyme activities associated with sucrose metabolism was investigated under natural and accelerated (treated with ethylene) ripening conditions. In fruit treated with ethylene, changes in flesh firmness, total sugar content, starch content, disease index, and activity of sucrose phosphate synthase (SPS), sucrose synthase (SS), acid invertase (AI), and neutral invertase (NI) were accelerated dramatically compared with untreated fruit with both 60% and 80% maturity. When fruit ripened under natural conditions, the changes in firmness, disease index, starch content, total sugar content, SPS activity, SS, AI, and NI activity in fruit with 80% maturity were significantly faster than those in fruit with 60% maturity. On the contrary, when fruit ripened under accelerated conditions, no significant differences in firmness, sugar, starch, disease index, SPS, SS, AI, and NI were observed between fruit harvested at 60% or 80% maturity. It is suggested that storage quality and sucrose-metabolizing enzymes of banana fruit stored under natural conditions are related to harvest maturity stage; storage quality of fruit with lower harvest maturity is better than fruit with higher maturity. However, when fruit ripening is accelerated by ethylene, the harvest maturity stage has no influence on storage quality and changes in sucrose-metabolizing enzymes.     

Effect of exogenous spermine on quality and sucrose metabolism of vegetable soya bean (Glycine max L.) during cold storage

Vegetable soya bean deteriorates quickly after harvest at ambient temperature due to loss of green colour and consequent yellowing of grains. To seek an effective method to control the postharvest quality, the effect of exogenous spermine on visual quality, sugar loss and sucrose‐metabolising enzyme activities of vegetable soya bean (Glycine max L.) during cold storage was investigated. The results showed that exogenous spermine (1.0 mmol L^?1) noticeably prolonged shelf life, inhibited the increase of weight loss and decay index and retained the colour. It also significantly minimised sucrose loss by regulating the activities of sucrose‐metabolising enzymes. Sucrose content negatively correlated with acid invertase (AI) activity at P < 0.05, while positively with sucrose phosphate synthase (SPS) activity at P < 0.01. There was no significant correlation with the activities of neutral invertase and sucrose synthase. These results indicated that the AI and SPS activities might play an important role in the control of sucrose metabolism resulting in reduction of sucrose loss.     

外源乙烯的处理时机对甘薯抑芽及碳水化合物代谢的影响

以未用外源乙烯处理的甘薯开始出现发芽迹象的时间为节点,采用1 g/L外源乙烯分别在节点前、节点后及储运全程进行处理,研究外源乙烯处理的不同时机对甘薯常温储运期间发芽的调控及碳水化合物代谢的影响。结果表明,所有时机乙烯处理均会促进甘薯呼吸,加速块根淀粉、还原糖含量下降,诱导α-淀粉酶、β-淀粉酶活性增大。节点后和全程1 g/L乙烯处理能更好抑制甘薯发芽,且能明显增强甘薯的磷酸蔗糖合成酶、中性转化酶活性,降低酸性转化酶活性,维持较高的可溶性总糖含量、蔗糖含量,甘薯甜度更高。     

Sugar metabolism and involvement of enzymes in sugarcane (Saccharum officinarum L.) stems during storage

Sugarcane (Saccharum officinarum L. cv. Badila) was harvested at the mature stage and stored at 2, 10, and 20 °C for 30, 90, and 120 days, respectively. Metabolic changes in the contents of sucrose and reducing sugar in relation to the activities of soluble acid invertase (SAI), neutral invertase (NI) and sucrose-phosphate synthase (SPS), in sugarcane juice, were studied. Extractable juice, sucrose and vitamin C declined significantly with increasing storage temperatures, while respiration rate increased. There was a rapid increase in titratable acidity during storage, with a more rapid rate at higher temperatures. A sharp increase in reducing sugar was observed within 20 days at 20 °C and 70 days at 10 °C, followed by a rapid decrease. Both SAI and NI activities showed a sharp increase within 15 days at 20 °C, followed by a rapid decrease, while a moderate increase occurred within 40–60 days at 10 °C. Slight increases were observed in SPS activity within 20 days at 20 °C and 50 days at 10 °C. Enzyme activities remained steady or underwent a small change in canes stored at 2 °C. Enzyme activities were significantly correlated with reducing sugar content.     

贮藏温度对采后龙眼果实糖代谢及其相关酶活性的影响

研究采后不同贮藏温度(25、15、4℃)对'石硖'龙眼果实糖组分及相关酶活性的影响.测定龙眼果肉可溶性固形物含量(SSC)、3种主要糖含量和糖代谢相关酶活性的变化,对不同贮藏温度各个时期样品进行主成分分析和载荷因子分析,并对各指标进行相关性分析.结果表明:25℃贮藏的龙眼SSC下降最快,贮藏8 d即从23.5％降至22...