月季切花衰老过程中多胺与乙烯的关系

月季切花瓶插过程中,内源腐胺在前2天略有增加,内源亚精胺、精胺、多胺总量则呈下降趋势,乙烯释放速率在第3天达到最高峰;多胺抑制剂甲基乙醛-双咪腙处理抑制了亚精胺、精胺的合成,增加了乙烯的释放速率;乙烯抑制剂氨氧乙酸处理推迟腐胺高峰的到来,降低了乙烯的释放速率,而且在瓶插期的前2天内源亚精胺、精胺含量较高。结果表明,具乙烯跃变型特征的月季切花衰老过程中,多胺与乙烯在其生物合成过程中相互竞争S-腺苷甲硫氨酸作为其合成的前体。     

月季切花衰老过程中多胺与乙烯的关系

月季切花瓶插过程中,内源腐胺在前２天略有增加,内源亚精胺,精胺、多胺总量则呈下降趋势,乙烯释放速率在第３天达到最高峰;多胺抑制剂甲基乙醛－双咪腙处理抑制了亚精胺,精胺的合成,增加了乙烯的释放速率;乙烯抑制剂氨氧乙酸处理推迟腐胺高峰的到来,降低了乙烯的释放速率,而且在瓶插期的前２天内业精胺、精胺含量较高,结果表明,具乙烯跃变型特征的月季切花衰老过程中,多与乙烯在其生物合成过程中相互竞争Ｓ－腺苷甲硫氨     

多胺对月季切花衰老过程中生理生化和瓶插寿命的影响

精胺处理可保持月季切花瓶插前期花瓣还原糖和蛋白质的较高水平、减缓花瓣和叶片细胞膜稼性的增加,减少共 积累以及降低乙烯释放速率,这与精胺处理后月季切花瓶插寿命提高相一致;但亚精胺处理对季切花瓶插寿命和改善观赏品质无明显影响。     

植酸对月季切花瓶插寿命的影响

用0.13％和0.013％植酸对月季切花进行处理,探讨了植酸对月季切花瓶插寿命及衰老过程中一些生理生化指标的影响.结果表明,013％和0.013％植酸处理的切花,瓶插寿命分别延长了2.3 d和1.4d.植酸处理抑制了O-2含量的增加和POD活性的提高,从而减轻了O-2对植物细胞的伤害即抑制丙二醛含量增加,同时抑制了可溶...     

多效唑对月季切花衰老的影响

本文研究了用多效唑处理的月季切花在瓶插期间的形态、生理变化,结果表明,多效唑能明显地缓解月季切花水分胁迫,改善体内水份平衡,促进切花开放,增加花朵鲜重和花径,抑制花瓣溶质外渗,延缓切花呼吸速率的下降和蛋白质降解的速率,从而延缓切花衰老。     

采后荔枝果实冷害过程中多胺含量的变化

以桂味荔枝果实为材料,研究冷害及外源亚精胺(Spd)处理对果实膜透性和内源多胺含量变化的影响。结果表明,在0℃下贮藏时果实发生冷害过程中,荔枝果皮中腐胺(Put)、Spd、精胺(Spm)含量在14d后明显增加,膜透性快速增大,21d时果皮出现明显的冷害褐变,Put进一步积累,而Spm含量下降,Spd保持较高水平。非冷害温度(3℃)下贮藏时,果皮多胺含量变化相对较小。0℃下果肉的多胺含量和变化幅度低于3℃果实,并延迟7d衰老。外源Spd处理明显提高果实内源多胺含量的同时,延缓了果皮相对膜透性增加,减轻了冷害。这表明果皮中Put的积累可能是荔枝果实冷害的结果,冷藏初期Spm含量的上升可能是果实对冷害的防卫反应。     

青霉素和比久对月季切花保鲜效应的研究

切花保鲜的关键技术是降低水分的散失和防止营养亏缺。以月季为材料,采用室内瓶插的方法研究 了青霉素和比久对切花保鲜的效应。结果表明:含不同浓度青霉素和比久B9的保鲜剂均能延长月季切花的 瓶插寿命,增加切花鲜重,增大花径,提高花瓣过氧化物酶(POD)的活性,改善切花体内水分状况,维持花瓣膜 结构的相对稳定。青霉素处理对提高月季切花保鲜品质的效果好于B9。     

表油菜素内酯对月季切花保鲜作用的研究

本文初步探讨了表油菜素内酯（epiBR）对瓶插月季切花的保鲜作用。与对照（蒸馏水）和基本液（2％蔗糖＋500mgL-1柠檬酸＋250mgL-8-羟基喹啉＋25mgAgNO3）相比,经epiBR处理（基本液＋0．1mgL-1epiBR）的月季切花花枝坚挺,蓝变延迟,瓶插寿命延长1-1.5倍。测定有关生理指标表明,epiBR处理对月季切花瓶插花枝前期鲜重的增加及后期的保持有明显作用。并显著延缓花瓣和叶片质膜相对透性的增加,还能使瓶插前期花瓣还原糖含量增加。epiBR处理对花瓣蛋白质和叶片叶绿素含量变化无明显影响,而对花瓣花青素水平下降有轻微的促进作用。     

不同保鲜剂对月季切花的保鲜效应

本试验研究不同保鲜剂对月季切花瓶插寿命、观赏品质的影响。正交试验表明,在供试保鲜剂的9个组合中,配方7(P₇)[0.2% Ca(NO₃)₂+0 Suc+400mg/L B₉+1mmol/L STS]保鲜效果最好,可明显延长月季切花瓶插寿命;以P₇保鲜剂喷洒花瓣可促进花朵生长发育;月季切花在瓶插过程中,其花瓣组织的pH值随切花的衰老而上升。     

NaCl胁迫对白刺幼苗体内游离态亚精胺和精胺含量的影响

以西伯利亚白刺试管苗为材料,研究其在0、50和200 mmol·L-1NaCl胁迫及外源环己胺调控下,生物量和体内多胺含量的改变,以探讨多胺对盐生植物白刺在盐胁迫下的生理调节功能.结果显示:50 mmol·L-1NaCl更有利于西伯利亚白刺的生长,处理后30 d白刺根系和地上部干重分别比对照增加75%和95%,处理15 d生根率比对照提高44.42%.而0(对照)和200 mmol·L-1NaCl都显著抑制白刺试管苗的生根与生长;200 mmol·L-1NaCl处理45 d时地上部干重比对照显著降低11.71%.白刺叶片中的多胺(精胺和亚精胺)含量随着盐浓度的增加呈降低趋势,茎和根中的多胺含量在200 mmol·L-1NaCl处理后才显著受到抑制;同时施环己胺和200 mmol·L-1NaCl处理使白刺叶片中的亚精胺含量显著低于200 mmol·L-1NaCl处理组,且叶绿素合成减少,细胞质膜透性增高.研究表明,西伯利亚白刺叶片内保持合适的多胺含量可能是其适应盐渍环境的重要机制之一.     

NaCl胁迫对菜用大豆种子多胺代谢的影响

采用蛭石栽培,在100 mmol·L-1NaCl胁迫下,对耐盐性不同的两个品种菜用大豆种子的丙二醛(MDA)含量和多胺(PAs)代谢进行了研究.结果表明:NaCl胁迫显著增加了菜用大豆种子的MDA含量,但耐盐品种‘绿领特早’(LL)的增幅低于盐敏感品种‘理想高产95-1’(LX).与LX相比,LL种子在整个NaCl胁迫期间均维持了相对较高的游离态精胺(Spm)、结合态Spm、结合态亚精胺(Spd)、束缚态Spd和束缚态腐胺(Put)含量,较高的(Spd +Spm )/Put 和(cPAs+bPAs)/fPAs值及较低的Put/PAs值,在胁迫中、后期(9～15 d)维持了相对较高的游离态Spd含量;胁迫期间,LL的精胺酸脱羧酶(ADC)长时期(6～15 d)保持相对较高的活性,而多胺氧化酶(PAO)则长时期(6～15 d)维持相对较低的活性.综上,LL具有较强的多胺合成能力及较强的Put向Spd和Spm以及游离态多胺向结合态和束缚态多胺转化的能力,进而有效抑制了细胞的膜脂过氧化,这可能是其耐盐性较强的重要原因之一.     

Endogenous polyamine content during in vivo maturation and in vitro culture of maize pollen

Changes in polyamine content during in vivo maturation and in vitro culture of maize (Zea mays L.) pollen were studied. The endogenous content of free, conjugated and bound polyamines was analyzed during 30 days of pollen evolution, in both developmental pathways (microsporogenesis and androgenesis). The induction of androgenesis from cold-pretreated uninucleate pollen results, in most of cases, in a lower total polyamine content than that of the in vivo uninucleate pollen. These differences indicate that polyamine metabolism is altered during the induction of androgenesis, and this could be a consequence of increased polyamine assimilation. In general, pollen stages that involve cell division (tetrades, pre-anthesis pollen and four-day cultured pollen) are characterized by a predominance of free Spd. The increase of Spd and Spm in 15-day cultured pollen, when the first embryoids are formed, outline the possible implication of these polyamines in embryogenetic processes. Furthermore, these findings may contribute to the improvement of maize androgenesis yield, especially in recalcitrant genotypes, by the exogenous application of polyamines or polyamine-inhibitors to the culture medium.Abbreviations PAs polyamines - Put putrescine - Spd spermidine - Spm spermine - S free polyamine fraction - SH conjugated polyamine fraction - PH bound polyamine fraction     

盐胁迫下大麦幼苗多胺的种类和状态与多胺氧化酶活性的关系

200 mmol/L的NaCl胁迫8 d大麦幼苗叶片和根系中的三种形态多胺都有不同程度地下降,其中游离态多胺含量的下降幅度最大;高氯酸不溶性结合态多胺含量变化较小.根系中PAO的活性先上升后下降,而叶片中PAO的活性先下降后上升.游离态多胺中,亚精胺和精胺(Spd Spm)的含量变化与相应部位PAO的活性变化趋势相反,表明PAO在盐胁迫下可能调节了游离态多胺的含量从而影响高氯酸可溶结合态与高氯酸不溶结合态多胺的含量.     

Exogenous polyamines enhance copper tolerance of Nymphoides peltatum

The protective effects of polyamines (PAs) against copper (Cu) toxicity were investigated in the leaves of Nymphoides peltatum. Cu treatment increased the putrescine (Put) level and lowered spermidine (Spd) and spermine (Spm) levels, thereby reducing the (Spd+Spm)/Put ratio in leaves. Exogenous application of Spd or Spm markedly reversed these Cu-induced effects for all three PAs and partially restored the (Spd+Spm)/Put ratio in leaves. It also significantly enhanced the level of proline, retarded the loss of soluble protein, decreased the rate of O2*- generation and H2O2 content, and prevented Cu-induced lipid peroxidation. Furthermore, exogenous Spd and Spm reduced the accumulation of Cu and effectively maintained the balance of nutrient elements in plant leaves under Cu stress. These results suggest that exogenous application of Spd or Spm can enhance the tolerance of N. peltatum to Cu by increasing the levels of endogenous Spd and Spm as well as the (Spd+Spm)/Put ratio.     

锌硼营养对苦瓜产量品质与叶片多胺、激素及衰老的影响

采用田间试验、植株生理生化测定方法,研究了锌硼营养对苦瓜(株洲长白)产量品质与叶片多胺、激素及衰老的影响。结果表明,在锌硼缺乏的土壤中施用硫酸锌和硼砂均可提高苦瓜产量,并可提高苦瓜蛋白质、Vc和17种氨基酸含量,尤其是人体必需氨基酸含量,降低NO3^-含量,改善苦瓜品质。这与锌硼提高了叶片多胺(PAs)、腐胺(Put)、亚精胺(Spd)、精胺(Spm)、抗坏血酸(ASA)、吲哚乙酸(IAA)、赤霉素(GA3)含量以及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)酶的活性,减少脱落酸(ABA)、丙二醛(MDA)含量,从而抑制膜脂过氧化有关试验结果同时表明苦瓜产量与叶片PAs、Put、Spd、Spm、GA3、SOD、POD、CAT呈极显著正相关,与叶片MDA与ABA含量呈极显著负相关。叶片MDA含量与ABA呈极显著正相关,而与PAs、Put、Spd、Spm、ASA、IAA、CA3、SOD、POD、CAT呈极显著负相关。     

Endogenous polyamine content during in vivo maturation and in vitro culture of maize pollen

Changes in polyamine content during in vivo maturation and in vitro culture of maize (Zea mays L.) pollen were studied. The endogenous content of free, conjugated and bound polyamines was analyzed during 30 days of pollen evolution, in both developmental pathways (microsporogenesis and androgenesis). The induction of androgenesis from cold-pretreated uninucleate pollen results, in most of cases, in a lower total polyamine content than that of the in vivo uninucleate pollen. These differences indicate that polyamine metabolism is altered during the induction of androgenesis, and this could be a consequence of increased polyamine assimilation. In general, pollen stages that involve cell division (tetrades, pre-anthesis pollen and four-day cultured pollen) are characterized by a predominance of free Spd. The increase of Spd and Spm in 15-day cultured pollen, when the first embryoids are formed, outline the possible implication of these polyamines in embryogenetic processes. Furthermore, these findings may contribute to the improvement of maize androgenesis yield, especially in recalcitrant genotypes, by the exogenous application of polyamines or polyamine-inhibitors to the culture medium.     

Polyamines reduce salt-induced oxidative damage by increasing the activities of antioxidant enzymes and decreasing lipid peroxidation in Virginia pine

Polyamines play an important role in the plant response to adverse environmental conditions including salt and osmotic stresses. In this investigation, the responses of polyamines to salt-induced oxidative stress were studied in callus cultures and plantlets in Virginia pine (Pinus virginiana Mill.). Our results demonstrated that polyamines reduce salt-induced oxidative damage by increasing the activities of antioxidant enzymes and decreasing lipid peroxidation. Among different polyamines used in this study, putrescine (Put) is more effective in increasing the activities of ascorbate peroxidase (APOX), glutathione reductase (GR), and superoxide dismutase (SOD), reducing the activities of acid phosphatase and V-type H+-ATPase, and decreasing lipid peroxidation in Virginia pine, compared to both spermidine (Spd) and spermine (Spm). When 2.1 mM Put, Spd, and Spm were separately added to the medium, higher diamine oxidase (DAO) and polyamine oxidase (PAO) activities were observed in callus cultures and plantlets, compared to the concentrations of 0.7 and 1.4 mM. The activities of these two enzymes produce hydrogen peroxide (H₂O₂), which may act in structural defense as a signal molecule and decreasing the protection of polyamines against salt-induced oxidative damage in Virginia pine.