外源IBA和PAs对苹果幼苗新根形成,多胺及核酸含量的影响

外源多胺（精胺、亚精胺、腐胺）可增加苹果幼苗新根数量，但效果不及ＩＢＡ；ＩＢＡ能够促进多胺与核酸的积累，有效期２０～２７天；多胺亦可增加ＲＮＡ、ＤＮＡ的含量；处理和对照内源多胺与核酸含量均同步变化。     

石竹花芽发生与内源多胺含量的关系

以石竹叶片为外植体，诱导愈伤组织、营养芽、花芽的培养基分别为ＭＳ＋ＺＴ２．５ｍｇ／Ｌ＋２，４－Ｄ０．３ｍｇ／Ｌ；ＭＳ＋ＺＴ１ｍｇ／Ｌ＋ＢＡ２ｍｇ／Ｌ＋ＮＡＡ０．２ｍｇ／Ｌ；ＭＳ＋ＩＢＡ０．５ｍｇ／Ｌ＋ＮＡＡ０．３ｍｇ／Ｌ。在石竹离体叶花芽形成过程中，内源多胺含量呈不同的变化趋势，腐胺、亚精胺含量上升，而二丙胺、精胺含量下降，表明多胺与石竹离体叶花芽分化有明显的内在联系。     

鸭梨,茌梨果实采前乙烯生物合成特性研究

鸭梨、茌梨果实均从盛花后１４５天进入呼吸跃变，同时伴随着乙烯释放高峰的出现。鸭梨的乙烯合成酶（ＥＦＥ）活性和氨基环丙烷羧酸（ＡＣＣ）含量高于茌梨，乙烯释放量的峰值是茌梨的４倍，两品种果实的ＥＦＥ活性变化与果实的呼吸跃变和乙烯释放量的变化同步，ＡＣＣ含量自盛花后１３５天，一直呈止升趋势。两品种果实内含有亚精胺、腐胺和精胺三种内源多胺，亚精胺与梨果实乙烯生物合成有关。     

三种多胺在苹果开花及坐果初期的生理作用

研究了苹果开花过程中花药、幼果（花托和子房）和贮藏花粉内源腐胺（Put）、亚精胺（Spd）、精胺（SPin）的含量变化及外源3种多胺对花粉萌发、雌蕊寿命和坐果的影响。结果表明：在开花过程中，花药中3种多胺的含量逐渐降低，花粉中的含量在贮藏期间和荫芽率同步降低；3种多胺浴液浸泡的花粉，其萌发率和花粉管长度极显著提高和增长；从蕾期到第一次生理落果，幼果多胺含量呈下降趋势，但受精幼果比未受精幼果的下降速度缓慢；第一次生理落果期，幼果内源多胺含量降到最低点；用3种外源多胺喷布花蕾，均延长了雌蕊寿命，增强了受精能力，提高了坐果率。     

多胺对镉胁迫下平邑甜茶根系损伤和NO生成的影响

以一年生平邑甜茶幼苗为试材,在水培条件下,通过根施硫酸镉、精胺、亚精胺,研究48 h后平邑甜茶根系内源游离态多胺含量、多胺氧化酶活性、过氧化氢含量、细胞损伤和线粒体特性的变化,并结合多胺合成抑制剂,测定一氧化氮生成量、一氧化氮合酶和硝酸还原酶活性的变化,以期揭示外源精胺和亚精胺缓解平邑甜茶根系镉损伤的生理机制,探讨多胺对一氧化氮生成的调控.结果 表明:镉胁迫导致过氧化氢含量增加,线粒体膜透性增大、膜电位降低、细胞色素c/a降低,一氧化氮生成量增加,根系细胞损伤严重.镉胁迫下多胺代谢异常,精胺和亚精胺含量明显降低,腐胺含量显著增加,(亚精胺+精胺)/腐胺显著降低,多胺氧化酶活性显著升高.外源添加精胺和亚精胺可降低镉胁迫下多胺氧化酶活性、过氧化氢含量和一氧化氮合酶活性、硝酸还原酶活性、一氧化氮生成量,稳定线粒体膜透性、提高膜电位和细胞色素c/a,恢复(亚精胺+精胺)/腐胺比值.而外施多胺合成抑制剂明显提高了一氧化氮合酶活性、硝酸还原酶活性和一氧化氮生成量.综上所述,外源添加精胺或亚精胺通过抑制一氧化氮生成,维护根系线粒体功能稳定,明显减弱了镉胁迫下根系细胞损伤程度,提高了植株的耐镉性.     

外源多胺对核桃雌雄花芽分化及叶片内源多胺含量的影响

 以‘辽宁1号’核桃为试材，研究了外源多胺对雌雄花芽分化及叶片内源多胺含量的影响。两年试验结果表明，喷施1×10^-3mol·L^-1和1×10^-4mol·L^-1的腐胺(Put)和亚精胺(Spd)能够显著增加雌花数量，提高雌雄花芽比例。在雌花芽生理分化期，芽内Put、Spd和精胺(Spm)含量升高并达高峰，叶片内Put含量累积并达高峰，而Spd、Spm含量变化不大。1×10^-3mol·L 的Put和Spd处理可提高叶片内源多胺含量，其中内源Put、Spd的含量升高早于内源Spm含量的升高。     

AgNO_3对梨叶片不定芽诱导过程中内源多胺含量的影响

为了探讨AgNO3在离体培养物形态发生中的作用,以金水梨组培苗为外植体,研究了不同浓度AgNO3对梨叶片再生不定芽过程中内源多胺含量的影响。结果表明,多胺含量会随着外植体细胞分裂分化迅速增加,其中腐胺含量在培养5d时形成高峰,精胺在20d时出现峰值,而亚精胺在培养过程中2次出现峰值。经AgNO3处理后叶片内源多胺含量与对照相比明显增多,其中以0.1mg/LAgNO3处理效果最明显。     

低氧胁迫对无土栽培网纹甜瓜幼苗多胺含量的影响

 研究了低氧胁迫处理对无土栽培网纹甜瓜幼苗叶片生长及游离态、结合态、束缚态多胺(腐胺、亚精胺和精胺) 含量的影响。结果表明, 低氧胁迫显著抑制了植株叶片的生长, 幼苗3种形态的腐胺、亚精胺和精胺含量显著提高; 但耐低氧性强的‘星光’比耐低氧性较弱的‘西域一号’幼苗生长较快, 而且游离态、结合态、束缚态的3种多胺含量较高, 表明较高多胺可能参与了网纹甜瓜耐低氧能力的调节。     

夜间温度对薄皮甜瓜果实膨大及多胺含量的影响

 为探讨果实内源多胺对温度胁迫的响应及其与果实膨大之间的关系，以薄皮甜瓜(Cucumis melo L.)'玉美人'为试材,研究了不同夜间温度对果实膨大及内源多胺含量的影响。结果表明，12 ℃处理的单果质量、果实横径、纵径最大,其次是15 ℃处理，18 ℃处理的单果质量、果实横径、纵径显著低于15 ℃处理，而9 ℃处理又显著低于18 ℃处理。从果实多胺含量变化情况看，除精胺外，果实总多胺、亚精胺、腐胺均随着果实的发育而减少，但不同夜温处理间存在差异，在夜温处理6 d内的果实快速膨大期，腐胺、亚精胺、精胺和总多胺含量均是9 ℃夜温处理显著低于12 ℃、15 ℃和18 ℃处理，18 ℃处理又显著低于12 ℃和15 ℃处理，而15 ℃和12 ℃处理间无显著差异。腐胺、亚精胺、总多胺含量与单果质量增长率呈显著或极显著正相关。这些结果说明夜间温度对薄皮甜瓜果实膨大的影响可能与多胺含量的变化有关。     

两个砂梨品种花芽分化期芽内内源多胺含量的动态变化

以不同成花能力的砂梨品种新水梨Pyrus pyri folia cv.Xinshui和丰水梨P.pyrifolia cv.fengshui为试材,分析了2个品种花芽分化期新梢和短枝芽游离态和束缚态多胺含量的变化.结果表明,在采样期内,砂梨新梢和短枝芽中5种内源多胺以腐胺、精胺和亚精胺含量较高,供试芽内源多胺含量丰水梨大于新水梨,说明在砂梨花芽分化期内源多胺含量与品种成花能力密切相关.     

低氧胁迫下黄瓜幼苗根系多胺代谢的变化

 利用外源Spd、PAO 抑制剂研究了黄瓜幼苗根系在低氧水培时的生长状况以及内源PAs、H₂O₂ 含量和PAO活性的动态变化。结果表明, 外源PAs对低氧胁迫下黄瓜幼苗根系的生长有促进作用;低氧处理后3种PAs含量都明显上升, 外源Spd和PAO抑制剂增加了根系中的PAs含量, 降低了根系中H₂O₂ 含量, 减缓了低氧伤害; PAs为低氧胁迫的应激产物, PAO为适应酶类, 其活性随PAs含量的变化而发生变化。     

Alterations in endogenous polyamines in bulbs of tuberose (Polianthes tuberosa L.) during dormancy

Changes in the levels of endogenous polyamines were determined in tuberose (Polianthes tuberosa L.) bulbs during their dormant periods. High free putrescine and low spermine and spermidine levels were associated during initial stages of dormancy. In contrast, high spermine and spermidine levels were related with dormancy release. The conjugated putrescine level increased during the period with an increase in conjugated spermine and spermidine levels. An inverse relationship between free and conjugated polyamines was noticed only for putrescine. The possible role of polyamines is discussed in relation to dormancy.     

苹果新根生理生化特性研究

以盆栽３年生新红星／怀来海棠（Ｍａｌｕｓｍｉｃｒｏｍａｌｕｓ）为试材，研究了生长根和吸收根的还原能力、碳氮物质代谢、吲哚乙酸氧化酶（ＩＯＤ）、过氧化物酶（ＰＯＤ）和超氧化物歧化酶（ＳＯＤ）的周年动态变化。结果表明，两类新根均于春、夏、秋形成３次吸收高峰，但还原能力的高峰只于夏秋季出现，其中夏季高峰最大；淀粉、糖、蛋白质含量及ＩＯＤ、ＰＯＤ活性随新梢旺长而降低，随新梢缓慢或停止生长而积累，氨基酸含量、ＳＯＤ活性相反；吸收根的吸收能力、淀粉、糖、蛋白质含量、ＰＯＤ、ＩＯＤ活性均显著高于生长根，但吸收根中氨基酸含量、ＳＯＤ活性却小于生长根，因而两类新根的代谢特点和功能不同，其发生数量和比例影响树势和植株的生长发育     

Effect of various polyamines on production of protocorm-like bodies in orchid—Dendrobium ‘Sonia’

Polyamines, putrescine, spermidine and spermine all at three concentrations viz., 0.2, 0.4 and 1.0 mM were tested, by supplementing to MS basal+4.44 μm BAP medium. The explant used was fractionated plb. Ethylene and methane was measured at 20 and 40 days after inoculation (DAI). Among various polyamines tested, maximum number of plb’s (protocorm-like bodies) were produced in putrescine 0.4 mM treatment. Increase (1.0 mM) or decrease (0.2 mM) in concentration caused a decrease in the production of plb’s. All spermidine and spermine treatments resulted in the production of less number of plb’s than control. No ethylene evolution was observed in any of the polyamine treatments. However, methane evolution was observed in all the polyamine treatments. The absolute amounts, of methane evolved could not be related to the observed plb’s production response. However, when the evolution of methane was more than 1 nmol per gram FW h⁻¹, poor plb’s production was observed.     

多胺及其合成抑制剂对梨花粉萌发及花粉管生长的影响

以丰水梨为材料,采集开花前1d或当天花蕾的花粉,进行离体培养。结果表明,精胺、亚精胺和腐胺在低浓度时均能促进离体花粉萌发和花粉管生长,但超过一定浓度时则对其起抑制作用。精胺、亚精胺和腐胺促进花粉萌发及花粉管生长的适宜浓度分别为0.005～0.025mmol/L、0.05～0.25mmol/L和0.05～0.25mmol/L。多胺的合成抑制剂甲基乙二醛-双-鸟苷基腙(MGBG)能抑制离体花粉萌发和花粉管生长。     

低温胁迫下4种苹果砧木叶片多胺的变化

以山定子(Malus baccata Borkh)、新疆野苹果[M.sieversii(Ledeb)Roem]、烟台沙果[M.prunifoli(Willd)Borkh]和莱芜难咽(M.micromalus Makino)等4种苹果砧木为试材,测定了低温胁迫下不同砧木叶片的多胺含量。结果表明,胁迫6 h时叶片的MDA含量可反映4个砧木的耐寒性,从高到低依次为山定子>新疆野苹果>莱芜难咽>烟台沙果;低温胁迫能明显诱导多胺总量(PAs)、腐胺(Put)、亚精胺(Spd)和精胺(Spm)的合成,耐寒性强的山定子和新疆野苹果PAs、Put和Spd增加显著,而耐寒性较弱的莱芜难咽和烟台沙果多胺和3种胺的变化不大。低温胁迫6 h时,MDA变化量与叶片PAs、Put、Spd变化量以及Put/PAs比值呈极显著或显著负相关,而与(Spd+Spm)/Put、Spd/PAs、Spm/PAs呈显著正相关,与Spm变化量无相关关系,表明当低温胁迫下叶片PAs、Put、Spd增加量较大时,苹果砧木耐低温胁迫的能力比较强,PAs、Put及Spd在胁迫条件下的增加量可作为苹果砧木耐低温胁迫能力高低的鉴定指标。     

龙眼光合特性及其影响因子的研究

 在田间和试验室条件下研究了龙眼叶片的光合作用特性。结果表明:龙眼叶片光合速率(Pn)的季节变化呈双峰曲线,最高峰在6月,次高峰在8月,5～9月Pn均维持在较高水平;春季(5月)Pn的日变化曲线为单峰型,高峰在正午,夏季(7月)Pn的日变化为双峰型,高峰在10时,16时有一小高峰;晴天Pn的日变化有明显的“午休”现象,多云天“午休”现象不明显,阴雨天pn较低,且无“午休”现象;Pn由负转正的叶龄为7～10天,30～40天叶龄叶片的Pn最高,60天后Pn缓慢下降;Pn的最适温度范围比较狭窄;环境温度为27℃和22℃时的光合最适温分别为28±2℃和25±2℃。龙眼的光合作用光补偿点和光饱和点分别为600～800μEm^-2s^-1和30～40μuEm^-2s^-1。最适土壤相对含水量为58％～84％。灌水临界期为土壤相对含水量38％～42％。     

Protective role of ornithine decarboxylase (ODC)/polyamines system in the myocardium induced by ischemic preconditioning in rats

AIM: To explore the protective role of ornithine decarboxylase (ODC)/polyamines system in the myocardium induced by ischemic preconditioning in rats.METHODS: The experiment model of simulating myocardial ischemia-reperfusion was replicated by Langendorff perfused rat heart. The hearts were randomly divided into six groups: control group, ischemic-reperfusion group (IR), weak ischemic preconditioning group (IPCw), strong ischemic preconditioning groups (IPCs) and inhibitor groups (DF-EG-IPCw and DF-EG-IPCs). The expression of ODC was quantified by Western blotting analysis. The contents of polyamines (putrescine, spermidine, spermine) in cardiac tissue were detected with high performance liquid chromatography. The hemodynamics was obtained using the PowerLab 8/SP TM data acquisition system. The infarct size was measured using triphenyltetrazolium chloride (TTC) staining and the apoptosis cardiomyocytes were observed under optic microscope after TUNEL method treatment. RESULTS: In contrast with control group, in IR group the putrescine contents increased, the expression of ODC was down-regulated, the contents of spermine and the total polyamine pool decreased (P<0.05). At the same time, the cardiac function declined, with an increase in myocardium infarct size and the apoptosis rate of cardiomyocytes (P<0.05). When compared with IR group in terms of LVDP, HR and CF, both IPCw and IPCs groups had significant improvements in cardiac functions (P<0.05). These two groups also had smaller myocardium infarct size (P<0.01) and apoptosis rate of cardiomyocytes (P<0.01). When compared with IR group, the expression of ODC, the contents of spermine and the total polyamine pool increased in both IPCw (P<0.05) and IPCs groups (P<0.01), but the putrescine contents declined. In the respective inhibitor groups of the weak and ischemic preconditioning, the expression of ODC and the levels of putrescine, spermidine, spermine and the total polyamine pool decreased remarkably (DF-EG-IPCw vs IPCw, P<0.05; DF-EG-IPCs vs IPCs, P<0.01), while the myocardium infarct size and apoptosis rate of cardiomyocyte were relatively bigger in both inhibitor groups (P<0.05). Also, the heart function decreased significantly in terms of LVDP, HR and CF compared to their matched ischemic preconditioning group (P<0.05).CONCLUSION: Ischemic preconditioning significantly up-regulates the ODC / polyamines system in Langendorff perfused rat hearts and provides protective effects on myocardium with ischemia/reperfusion injury. Inhibition of bio-synthesis of polyamine abolishes the cardiac function improvement and the decreases the infarct size and apoptosis rate induced by ischemic preconditioning. It reveals that the ornithine decarboxylase (ODC) /polyamines system may be involved in the protection of myocardium induced by IPC in rats.