甘露醇对小麦细胞IAA氧化酶、过氧化物酶及GST活性的影响

研究了16 g/L甘露醇处理对小麦细胞再分化、细胞IAA氧化酶、IAA过氧化物酶、 谷胱甘肽转移酶和过氧化物酶活性的影响。结果表明,甘露醇处理使小麦细胞再生能力明显降低,引起细胞蛋白质含量、IAA过氧化物酶和GST活性明显降低;但使细胞IAA氧化酶和POD活性明显增高。     

甘露醇和6—BA处理对水稻细胞过氧化物酶及IAA氧化酶活性的影响

研究了甘露醇和６０ＢＡ处理对水稻服浮细胞再分化、过氧化物酶及ＩＡＡ氧化酶的影响。结果表明,甘露醇处理能延迟水稻细胞衰老,提高细胞再分化能力,降低细胞过氧化物酶和ＩＡＡ氧化酶活性,６－ＢＡ（２ｍｇ／Ｌ）虽然明显降低细胞过氧化物酶活性,但对ＩＡＡ氧化酶及细胞衰老无明显影响,讨论了过氧化物酶及ＩＡＡ氧化酶在水稻胚性细胞形成上的可能作用。     

表油菜素内酯对黄瓜幼苗下胚轴过氧化物酶和IAA氧化酶活性的影响

黄瓜幼苗用0.1～1 ppm表油菜素内酯(epiBR)处理1～3d后,下胚轴中过氧化物酶活性明显低于对照;随着处理浓度的增加和处理时间的延长,与对照之间的差别愈趋增大。当浓度高于1ppm时,过氧化物酶的活性不再继续降低。表油菜素内醋对过氧化物酶活性的这种抑制作用需经约1O h的滞后期。IAA氧化酶的活性变化与过氧化物酶相似,epiBR处理时间愈长酶活性增加愈趋缓慢。 经IAA处理的下胚轴,过氧化物酶和IAA氧化酶的活性变化与对照无明显差异。这提示油菜素内酯与IAA促进生长可能是通过不同的作用方式。     

营养胁迫诱导的油菜子叶衰老过程中IAA氧化酶和细胞分裂素氧化酶活性的变化

以离体油菜子叶为材料,研究了营养胁迫诱导的子叶衰老过程中吲哚乙酸氧化酶(IAA氧化酶)和细胞分裂素氧化酶活性的变化。在光照条件下,离体子叶在不含任何无机元素的0．8％的琼脂中培养9d后,出现明显的衰老迹象(叶绿素含量下降,丙二醛含量上升),15d时完全死亡。在营养胁迫诱导的衰老过程中,IAA氧化酶和细胞分裂素氧化酶的活性表现出相似的变化趋势,在诱导处理1d时,两种酶的活性均比处理前有明显下降,之后又随着衰老进程逐渐上升。IAA氧化酶活性在诱导处理11d时达到高峰,超出处理前30％以上;比对照高出1倍以上;而细胞分裂素氧化酶活性在诱导处理13d时达到高峰,比对照高出3倍以上,也超过了处理前的水平。衰老过程中IAA氢化酶和细朐分裂素氧化酶活性的上升可能是导致内源激素含量下降的重要原因。     

低聚糖诱导小麦抗条锈性及相关酶活性变化的研究

用自行设计的方法从植物细胞壁中得到的低聚糖提取物5号对小麦浸种和苗期喷雾处理,均使接种条锈菌的小麦叶片产生了明显的过敏性坏死反应。对几种与抗病性密切相关的酶活性变化的分析表明,经低聚糖预先处理能显著提高小麦叶片的过氧化物酶(POD)、多酚氧化酶(PPO)和苯丙氨基酸解氨酶(PAL)的活性。     

苹果成熟过程中吲(口朶)乙酸氧化酶和过氧化物酶的研究

苹果成熟前后果柄的过氧化物酶(PRO)活性比果实中的高,两者的 PRO 活性皆在呼吸高峰(约在盛花后150天)前5天显著上升,当时果柄中的 PRO 活性比果实中的约高14倍。果实中的同工酶在盛花后145天,酶谱的位置有变动,酶带数目不变;果柄中的酶带数目从7条增加到9条。果实中的 PRO 活性比吲哚乙酸(IAA)氧化酶活性高,尤其是果柄中的 PRO活性比 IAA 氧化酶活性高得多。推测 IAA 或其它成熟抑制物质在进入果实以前,可能主要被果柄中的 PRO 氧化分解,而 IAA 氧化酶所起的作用较小。     

乙烯利对甘蔗分蘖期茎三种酶活性的影响及其与分蘖的关系

在分蘖前期喷施适宜浓度(100mg/L)乙烯利提高了蔗茎的过氧化物酶活性和IAA氧化酶的活性。用100mg/L乙烯利处理后,两个品种根部的过氧化物酶和IAA氧化酶活性明显高于上部的活性,并且比对照和400mg/L乙烯利处理的效果明显。乙烯利处理后新台糖16号上部节间的酸性转化酶活性始终高于下部节间的酶活性,其中100mg/L乙烯利处理下部节间的明显低于对照的;乙烯利处理后新台糖22号茎内的酸性转化酶活性也低于对照的,但与对照的差异相对比新台糖16号的小。     

茵根真菌感染墨兰与建兰根状茎对呼吸速率和几种氧化酶活性的影响

用从野生建兰根部分离的菌根真菌P15菌株感染墨兰Cymbidium sinense和建兰Cymbidiumensiolium的根状茎后,使寄主的呼吸速率、细胞色素C氧化酶、过氧化物酶活性明显增高,而感染前后IAA氧化酶活性变化不明显.两个品种相比较,建兰根状茎的呼吸速率、细胞色素C氧化酶和过氧化物酶活性均比墨兰的高,但墨兰的根状茎IAA氧化酶活性则高于建兰.     

菌根真菌感染墨兰与建兰根状茎对呼吸速率和几种氧化酶活性的影响

用从野生建兰部分离的菌根真菌P15菌株感染墨兰Cymbidium sinense和建兰Cymbidium ensifolium的根状茎后,使寄主的呼吸速率、细胞色素C氧化酶、过氧化物酶活性明显增高,而感染前后IAA氧化酶活性变化不明显。两个品种相比较,建兰根状茎的呼吸速率、细胞色素C氧化酶和过氧化物酶活性均比墨兰的高,但墨兰的根状茎IAA氧化酶活性则高于建兰。     

小麦原生质体分离过程中生理状态的变化

酶解处理使小麦叶肉原生质体膜流动性降低,膜脂过氧化产物丙二醛积累,说明脱壁过程对细胞有伤害作用,损伤位点可能发生在膜上,胚性愈伤组织的具有分裂能力的原生质体,不表现上述变化,酶解脱壁还使超氧化物歧化酶和过氧化氢酶活性上升,过氧化物酶在叶肉原同体中活性下降,过氧化物酶在叶肉原同体中活性下降,在胚性愈伤组织来源的原生质体中活性上升,以上结果表明,在原生质体分离过程中,细胞的生理特性发生了变化;膜损伤的     

Effect of some reducing agents on water stress-induced oxidative and deteriorative processes ofVigna seedlings

Decreasing substrate osmotic potential produced in seedlings ofVigna catjang Endl. (cv. Pusa Barsati) proportional decrease in relative water content and leaf water potential, increase in respiration rate, proline content, H₂O₂ content, and the activities of indole acetic acid oxidase, ascorbic acid oxidase, peroxidase and glycolate oxidase but decrease in catalase activity and glycolate content. Pretreatment with reducing agents like L-cysteine or reduced glutathione (10?3 M) caused lower decrease in the relative water content, leaf water potential and glycolate content and reduced the rise of respiration rate, proline content and H₂O₂ content and also the activities of aforementioned oxidative enzymes, except catalase activity which was increased. Such treatments also maintained the chlorophyll and protein levels and decreased the tissue permeability. It was concluded that the treatment ofVigna seedlings with reducing agents reduced the deteriorative changes and oxidative processes which are characteristic of water stressed tissue.     

Influence of indole acetic acid on antioxidant levels and enzyme activities of glucose metabolism in rat liver

Indole acetic acid (IAA) is an auxin and can be synthesized in animals. This compound is metabolized in vitro by peroxidase, producing reactive oxygen species. The toxic effect of indole acetic acid in leukocytes is associated with peroxidase activities and these processes have been implicated in activation of glucose and glutamine metabolism. However, studies in vitro have shown that IAA, in absence of peroxidase, is an antioxidant almost as high in potency as those of other indolic compounds. The purpose of this study was to investigate the possible involvement of a toxic effect of indole acetic acid in the liver, as evidenced by oxidative stress and enzyme activities of the glucose pathway. The animals received IAA by subcutaneous or gavage administration in a phosphate buffered saline (the control group received only the phosphate buffered saline). The other groups received IAA at concentrations of 1 mg, 18 mg and 40 mg per kg of body mass per day. Treatments with 18 mg and 40 mg IAA decreased the activity of catalase by both subcutaneous (30% and 26%) or gavage administration (19% and 28%), respectively. A similar effect was observed on the activity of glutathione peroxidase of animals exposed to 18 mg and 40 mg IAA: A decrease of 34% and 29%, respectively, for subcutaneous administration and a decrease of 29% and 25%, respectively, for gavage administration. However, in neither source of administration did the acid alter superoxide dismutase, glutathione reductase and myeloperoxidase activities. Another alteration was observed in respect of reduced glutathione content in this organ. The lipid peroxidation level showed a significant decrease with subcutaneous (30%, 29% and 24%) and gavage administration (25%, 26% and 24%) using 1 mg, 18 mg and 40 mg of IAA, respectively compared with the control. The reduced glutathione content and catalase activity in the plasma were not altered by either of the two methods of administration. In addition to these findings, after subcutaneous or gavage administration of IAA, the activities of hepatic enzymes of glucose metabolism were not affected (glucokinase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase and citrate synthase). Evidence is presented herein that IAA did not have a pro-oxidant effect in the liver as deduced from a reduction of catalase and glutathione peroxidase activities, a decrease of lipid peroxidation content and no alteration of the pool of reduced glutathione. The effects of IAA were independent of the way of administration.     

Inhibition of IAA oxidase activity of wheat anionic peroxidase by chitooligosaccharides

The study demonstrated that chitooligosaccharides with a molecular weight of 5–10 kDa and a degree of acetylation of 65% exhibited an auxin-like effect in wheat plants and also played an important role in regulating the activity of polysaccharide (chitin)–specific anion isoenzymes of peroxidase oxidizing indole acetic acid. Changes in the kinetic parameters of the interaction of the wheat anionic chitin-specific peroxidase with pI ～3.5 with chitin oligomers in the presence of indoleacetic acid were pH-depended and indicated that chitooligosaccharides significantly impair the ability of the enzyme for oxidation at pH levels of 4.2 and 6.0. It can be assumed that chitooligosaccharides not only induce protective plant systems but also increase the accumulation of auxin in plant tissues, thus adversely affecting a number of components of the plant protective system against pathogens.     

不同穗型小麦品种分蘖发育的代谢基础研究

比较研究了大穗型和多穗型小麦品种的分薛发育特征及其代谢基础。结果表明,与多穗型品种相比,单株分蘖较少的大穗型品种分蘖期具有较低的IAA氧化酶（IAAO）活性、较高的IAA含量和较强的碳代谢活性。在分蘖的两极分化期,大穗型品种在碳、氮代谢和同化物分配方面存在较强的主茎优势,因此,其分蘖较难继续发育成穗。     

Changes in peroxidase and IAA oxidase activities during cell elongation in Phaseolus hypocotyls

Cytoplasmic and salt-extracted peroxidase and IAA oxidase activities were studied in Phaseolus vulgaris hypocotyls treated with gibberellic acid (GA, 200 μM), naphthyl acetic acid (NAA, 100 μM) and distilled water control (DW). Peroxidase activity was assayed with four hydrogen donors during the initial phase of hypocotyl elongation. Though peroxidase activity showed a decreasing trend with time in all the hydrogen donors studied; considerable variation with different hydrogen donors was observed. NAA had maximum peroxidase activity as compared to DW or GA treatment. The activity showed a clear inverse correlation with hypocotyl growth. IAA oxidase activity showed a similar trend with growth as peroxidase activity. A highly significant correlation was observed between peroxidase and IAA oxidase activities and high molecular weight xyloglucan content (P<0.001). Finally, the possible role of peroxidase and IAA oxidase activities in hypocotyl elongation growth is discussed.     

Root Development Enhanced by Using Indole-3-butyric Acid and Naphthalene Acetic Acid and Associated Biochemical Changes of In Vitro Azalea Microshoots

Based on the importance of producing in vitro adventitious roots, this study was carried out to investigate the effects of indole-3-butyric acid (IBA) and naphthalene acetic acid (NAA) at a concentration of 2 mg L^?1 on the formation of adventitious roots of azalea and their impact on biochemical changes and endogenous hormones. The rooting percentage, root number, and root length were increased in the microshoots of both studied cultivars (‘Mingchao’ and ‘Zihudie’) when the growth medium was supplemented with IBA. Additionally, peroxidase, indole acetic acid oxidase, hydrogen peroxide, and soluble protein contents were improved in both cultivars by auxin treatments especially during the first 7 days of the rooting period. However, application of IBA and NAA increased catalase and polyphenol oxidase in both cultivars during the first 14 and 28 days of culture. The increase in endogenous indole acetic acid (IAA) levels was accompanied by low activity of IAAO during most periods of root induction of microshoots in all treatments. Endogenous gibberellic acid levels were increased after 7 days of culture and then increased again after 28 days of culture. In contrast, the levels of endogenous zeatin riboside and isopentenyl adenosine were decreased with auxin treatments in the first period of the rooting process and then increased after 21 and 28 days of culture. The present study demonstrated that IBA at a concentration of 2 mg L^?1 has a strong effect on azalea rooting. Moreover, the efficiency of IBA and NAA effects on biochemical changes during adventitious root induction was investigated, which may provide new horizons of in vitro rooting production and provide valuable information for the micropropagation of Rhododendron plants.     

磷石膏浸提液对豌豆种子生理及幼苗生长的影响

利用不同浓度的磷石膏浸提液处理豌豆种子,测定豌豆种子淀粉酶活性、可溶性糖、种子生命力、吲哚乙酸含量、吲哚乙酸氧化酶活性和发芽率、苗高、植株鲜重。结果表明:磷石膏浸提液处理后,豌豆种子可溶性糖含量和吲哚乙酸含量分别比对照增加6.7%～43.3%和9.4%～40.8%。豌豆幼芽中α-淀粉酶活性和吲哚乙酸氧化酶活性分别比对照高出8%～64%和15.2%～30.9%;发芽率、苗高和植株鲜重分别比对照提高10%以上。表明磷石膏能促进豌豆萌发和生长。     

Biochemical studies of the regeneration of the root cuttings ofClerodendrum viscosum Vent

The contents of reducing sugars, proteins and ascorbic acid and the activities of protease, peroxidase, catalase, indole acetic acid oxidase, ascorbic acid oxidase, succinic dehydrogenase and the rate of respiration were investigated in regenerating and non-regenerating parts ofClerodendrum viscosum Vent. root cuttings. All the above variables have registered higher in the regenerating parts, particularly at the distal end where roots appear, than in the non-regenerating parts of root cuttings. The contents of metabolites and the activities of enzymes in the presence of endogenous cytokinins at the proximal end and auxins at the distal end, were compared and discussed in relation to the initiation of shoots and roots at two ends of root cuttings. In general it was concluded that interacting hormonal and nutritional factors must be appropriate to initiate shoots or roots in the root cuttings.