Met对渗透胁迫下小麦幼苗内源多胺含量和乙烯产生的影响

渗透胁迫下,小麦幼苗内源多胺含量和乙烯产生均明显增加,再用0．4mmoL甲硫氨酸掺人处理后,乙烯释出加速,精胺含量进一步增多,亚精胺含量变化不大,腐胺的含量几乎减少到胁迫前的水平。可见,渗透胁迫下,甲硫氨酸既可以在Met循环中以甲硫氨酸与腐胺联合生成亚精胺,进而再与亚精胺联合生成精胺,又可以S-腺苷甲硫氨酸分解生成5’-甲硫基腺苷和氨基环丙烷羧酸,最后由氨基环丙烷羧酸加氧生成乙烯。     

采后梨果实皮层和髓中EFE活性、ACC和多胺含量变化及其与乙烯生成的关系

菊水梨皮层和髓的乙烯合成酶（ＥＦＥ）活性和氨基环丙烷羧酸（ＡＣＣ）含量及其果实乙烯释放量均分别高于二十世纪梨。在同一品种果实的皮层和髓中,ＡＣＣ含量无明显差异,但髓的ＥＦＥ活性明显高于皮层。梨果实内含有丁二胺、亚精胶和精胺３种内源多胺,而以丁二胺和亚精胺含量为最高,精胺含量虽低但较稳定。果实在乙烯释放高峰出现前,其皮层和髓中的丁二胺和亚精胺含量变化有明显差异。采后梨果实的乙烯生成与果实内ＥＦＥ活性,ＡＣＣ含量、多胺含量的变化有密切关系,而乙烯生成的差异不仅表现在品种间,而且在果实的皮层和髓之间也存在差异,梨果实的髓似乎对整个果实的乙烯生成有更重要的影响。     

土壤干旱对冬小麦旗叶乙烯释放、多胺积累和细胞质膜的影响

土壤水分亏缺时,小麦旗叶的乙烯释放量增加,三种多胺（精胺、亚精胺、腐胺）的含量在小麦灌浆初期显著增加,而在小麦灌浆末期除腐胺外均降低。外施５００ｍｇ／Ｌ的亚精胺溶液能减弱小麦叶片的膜脂质过氧化程度。土壤水分亏缺时膜透性增大,膜脂过氧化物丙二醇含量升高,导致不饱和脂肪酸指数下降,亚麻酸含量下降。严重土壤水分胁迫下,过氧化物酶的活性升高。这些结果表明土壤干旱损害小麦旗叶质膜,促其衰老。研究表明,随着受旱程度的提高,小麦旗叶遭受的损伤逐渐加重,植株对土壤干旱的适应性亦逐渐降低。     

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。     

化学调节剂对水稻离体幼穗乙烯生成的影响（简报）

CoCl2、NiSO4及高浓度的GA3抑制水稻离体幼穗乙烯的生成,而2,4-D、Ag2S2O3和乙烯利则明显促进乙烯生成。玉米赤霉烯酮的抑制不明显。精胺和亚精胺的影响不大。     

亚精胺对水分胁迫下玉米幼苗内源乙烯和多胺含量的影响（简报）

同正常供水相比,水分胁迫引起玉米幼苗叶和根中乙烯在短时间内出现峰值,随后下降且保持较低水平。叶中腐胺、亚精胺和精胺均先降后升,喷施外源亚精胺使叶中乙烯释放减少,亚精胺和精胺含量降低。根中腐胺、亚精胺含量在回升后又略有下降,精胺则呈下降趋势。     

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     

钙对渗透胁迫下玉米幼苗内源激素和多胺含量的影响

渗透胁迫下,玉米轩叶片中内源ＡＢＡ含量增加,乙烯在较短时间内出现峰值,叶中腐胺、亚精胺和精胺先降后升。施ＣａＣｌ２水溶液后叶中ＡＢＡ增加的起始时间延迟,乙烯释放量减少,Ｐｕｔ、Ｓｐｄ、Ｓｐｍ含量均增高。     

水稻细胞质雄性不育系幼穗发育过程中多胺与乙烯的关系初探(英文 )

利用ＨＰＬＣ和ＧＣ分别测定了水稻细胞质雄性不育系及其保持系幼穗多胺（ 腐胺,亚精胺和精胺） 含量和乙烯释放速率,并研究了外施多胺合成抑制剂ＭＧＢＧ 和乙烯前体ＡＣＣ生成抑制剂ＡＶＧ 对两系幼穗多胺含量和乙烯释放速率以及花粉育性的影响。结果表明, 不育系幼穗乙烯释放速率显著高于其保持系幼穗, 外施ＡＶＧ 引起两系幼穗乙烯释放速率下降,并使不育系花粉育性得以部分恢复; 不育系幼穗多胺含量显著低于保持系幼穗, 外施ＭＧＢＧ 使两系幼穗Ｓｐｄ 和Ｓｐｍ 含量下降, 并使保持系花粉育性降低。外施ＡＶＧ 抑制乙烯释放,促进多胺合成;而外施ＭＧＢＧ 抑制Ｓｐｄ和Ｓｐｍ 合成, 却促进乙烯的释放; 而且,乙烯释放速率与多胺（精胺和亚精胺） 含量呈显著负相关。提示在水稻ＣＭＳ 系及其保持系幼穗发育过程中乙烯与多胺（ 精胺和亚精胺） 的生物合成竞争ＳＡＭ。     

钙对渗透胁迫下玉米幼苗内源激素和多胺含量的影响(简报)

渗透胁迫下,玉米幼苗叶片中内源ABA含量增加,乙烯在较短时间内出现峰值,叶中腐胺（Put）、亚精胺（Spd）和精胺（Spm）先降后升。喷施CaCl2水溶液后叶中ABA增加的起始时间延迟,乙烯释放量减少,Put、Spd、Spm含量均增高。     

干旱胁迫下小麦幼苗根、叶多胺含量和多胺氧化酶活性的变化

 以抗旱性不同的两个小麦品种（‘晋麦33’和‘温麦8’）（Triticum aestivum cv. Jinmai 33 and Wenmai 8）为材料,研究了干旱胁迫下多胺含量和多胺氧化酶活性的变化。结果表明：旱过程中,幼苗根、叶中腐胺（Put）、亚精胺（Spd）、精胺（Spm）3种多胺含量和多胺氧化酶（PAO）活性先迅速升高,而后下降。与抗旱性弱的‘晋麦33’相比,抗旱性强的品种‘温麦8’幼苗根、叶中Spd、Spm 含量初期升高幅度大,之后下降速率减慢;PAO活性的变化与之相反,‘晋麦33’的PAO活性提高的幅度大于‘温麦8号’。多胺含量和PAO活性在小麦幼苗的根与叶之间呈极显著正相关。干旱初期,小麦根、叶中多胺迅速积累可能是干旱胁迫反应的一个信号,随后较高的Spd、Spm 水平有利于增强小麦幼苗的抗旱性。     

水分胁迫对小麦幼苗叶片多胺含量的影响

水分胁迫下小麦幼苗叶片多胺含量变化的研究表明,聚乙二醇(PEG)的渗透胁迫明显提高了抗旱性强的周麦系列幼苗叶片游离态Put、Spd和Spm的含量和抗旱性弱的温麦6号的Put含量。外源Spd显著提高了水分胁迫下温麦6号的Spd的含量,对其抗性也有所改善。外源MGBG(Spd和Spm生物合成抑制剂)可提高水分胁迫下周麦12号Put的含量,但降低了Spd和Spm的含量和幼苗的抗性。     

干旱期间春小麦叶片多胺含量与作物抗旱性的关系

使用两种抑制剂MCBG(抑制SAMDC活性)和AOA(抑制ACC合成酶活性)研究了干旱期间两个春小麦品种8139(抗旱性较弱)和504(抗旱性较强)叶片多胺(Put、Spd和Spm)含量、RWC水平、SOD和POD活性以及MDA含量的变化,并由此探讨了不同类别多胺与作物抗旱性的关系以及多胺与乙烯在作物对干旱胁迫响应过程中对共同前体SAM的竞争趋向及其生理意义。     

Abscisic acid promotes accumulation of toxin ODAP in relation to free spermine level in grass pea seedlings (Lathyrus sativus L.).

Interrelationship among abscisic acid (ABA) content, accumulation of free polyamines and biosynthesis of beta-N-oxalyl-l-alpha,beta-diaminopropionic acid (ODAP) was studied in grass pea (Lathyrus sativus L.) seedlings under drought stress induced by 10% polyethylene glycol (PEG6000). Increase of ABA content occurred prior to that of ODAP and polyamine contents, and was found significantly positive correlation between ABA content and ODAP content. Addition of exogenous ABA increased ODAP content in leaves. On the other hand, pretreatment with alpha-difluoromethylarginine (DFMA), a polyamine biosynthesis inhibitor, significantly suppressed the accumulation of free putrescine (Put), free spermidine (Spd) and free spermine (Spm), which in turn inhibited biosynthesis of ODAP in well-watered leaves. Meanwhile, addition of exogenous Put alleviated DFMA-induced inhibition on the biosynthesis of Put and Spd, but did not affect the biosynthesis of Spm and ODAP in well-watered leaves. Same result was also achieved in drought-stressed leaves. Increasing accumulation of ODAP was significantly correlated with increasing Spm content (R=0.7957**) but not with that of Spd and Put. Therefore, it can be argued that ABA stimulated the biosynthesis of ODAP simultaneously with increasing the level of free Spm under drought stress condition.     

干旱胁迫下多裂骆驼蓬(Peganum multisectum Bobr)叶片乙烯释放和多胺含量变化与活性氧积累的关系

通过盆栽土培试验研究了干旱胁迫下多裂骆驼蓬(Peganum multisectum Bobr)叶片乙烯释放、多胺含量、活性氧水平及细胞膜透性的动态变化.结果表明,随着土壤干旱强度的增加和胁迫时间的延长,多裂骆驼蓬叶片内丙二醛(MDA)含量和细胞膜透性呈递增变化趋势;轻度胁迫下,乙烯产生速率、多胺(Put、Spm、Spd)、活性氧(O2-·、H2O2)和MDA含量及多胺氧化酶(PAO)活性随胁迫时间延长无明显变化;中度和重度胁迫初期(胁迫后0～30d)腐胺(Put)、精胺(Spm)和亚精胺(Spd)含量快速提高,乙烯生成速率下降,而O2-·、H2O2、MDA含量和PAO活性相对平稳;胁迫后期(胁迫后45～75d)乙烯生成速率增高,Put、Spm和Spd含量下降, O2-·、H2O2和MDA含量大幅度增加,膜透性增大,且乙烯释放与O2-·、H2O2含量呈显著正相关.表明中度和重度胁迫下多裂骆驼蓬叶片存在乙烯和多胺合成的相互制约,乙烯释放增加诱导活性氧积累导致膜透性急剧增大.     

Involvement of polyamines in the drought resistance of rice

This study investigated whether and how polyamines (PAs) in rice (Oryza sativa L.) plants are involved in drought resistance. Six rice cultivars differing in drought resistance were used and subjected to well-watered and water-stressed treatments during their reproductive period. The activities of arginine decarboxylase, S-adenosyl-L-methionine decarboxylase, and spermidine (Spd) synthase in the leaves were significantly enhanced by water stress, in good agreement with the increase in putrescine (Put), Spd, and spermine (Spm) contents there. The increased contents of free Spd, free Spm, and insoluble-conjugated Put under water stress were significantly correlated with the yield maintenance ratio (the ratio of grain yield under water-stressed conditions to grain yield under well-watered conditions) of the cultivars. Free Put at an early stage of water stress positively, whereas at a later stage negatively, correlated with the yield maintenance ratio. No significant differences were observed in soluble-conjugated PAs and insoluble-conjugated Spd and Spm among the cultivars. Free PAs showed significant accumulation when leaf water potentials reached -0.51 MPa to -0.62 MPa for the drought-resistant cultivars and -0.70 MPa to -0.84 MPa for the drought-susceptible ones. The results suggest that rice has a large capacity to enhance PA biosynthesis in leaves in response to water stress. The role of PAs in plant defence to water stress varies with PA forms and stress stages. In adapting to drought it would be good for rice to have the physiological traits of higher levels of free Spd/free Spm and insoluble-conjugated Put, as well as early accumulation of free PAs, under water stress.     

渗透胁迫对小麦胚芽鞘内多胺的种类、形态和含量的影响

用高压液相色谱法研究了豫麦18（抗旱性较强）和扬麦9号（抗旱性较弱）小麦胚芽鞘中三种不同形态的多胺（polyamine,PA）：游离态多胺（PA）、高氯酸可溶性结合态多胺（ps结合态PA）和高氯酸不溶性结合态多胺（PIS结合态PA）与渗透胁迫的关系。结果发现：渗透胁迫2d,豫麦18胚芽鞘中的游离态Spd和游离态Spm的含量明显上升,而扬麦9号的游离态Put的上升明显。S-腺苷蛋氨酸脱羧酶（S—AMDC）的抑制剂——甲基乙二醛-双（鸟嘌呤腙）（MGBG）处理豫麦18,明显抑制了渗透胁迫诱导的游离态Spd和游离态Spm的增加,并且加重了渗透胁迫伤害,外源Spd处理扬麦9号明显促进了渗透胁迫诱导的游离态Spd和游离态Spm的增加,并且减缓了渗透胁迫的伤害。渗透胁迫下,豫麦18胚芽鞘中的PS结合态PA和PIS结合态PA的上升幅度都明显大于扬麦9号。菲咯啉（o—Phen）抑制渗透胁迫下PIS结合态PA的合成并加重了渗透胁迫对胚芽鞘的伤害。这些结果表明：小麦胚芽鞘中的游离态Spd、游离态Spm、PS结合态PA和PIS结合态PA的升高有利于增强渗透胁迫抗性。     

Seasonal Changes of Polyamine Concentrations and Arginine Decarboxylase Activities in Leaves of 4 Ecotyes of Reeds

The seasonal changes of polyamine concentrations and arginine decarboxylase (ADC, EC 4.1.1. 1. 9)activities were investigated in the leaves of 4 ecotypes of reeds (Phragamites comrnunis Trinius)distributed over Hexi Corridor of Gansu province. The leaves of all ecotypes of reeds contained the same kind of polyamines and showed the same trend of decrement in total amuonts of potyamines with change of seasons. From May to September, the reeds which grow in arid and saline habitat maintained higher level of spermidine (Spd)and spermine (Spm)with no accumulation of putrescine (Put), resulting in low ratios of Put to other polyamine (Spd and Spm), whereas opposite results were observed in swamp reeds. These results indicate that the adaption of reeds to drought and salt stresses may correlate with Put synthesis via ADC pathway and the quick transformation of Put into Spd and Spm.     

The Relationship between Polyamines and Hormones in the Regulation of Wheat Grain Filling

The grain weight of wheat is strongly influenced by filling. Polyamines (PA) are involved in regulating plant growth. However, the effects of PA on wheat grain filling and its mechanism of action are unclear. The objective of the present study was to investigate the relationship between PAs and hormones in the regulation of wheat grain filling. Three PAs, spermidine (Spd), spermine (Spm), and putrescine (Put), were exogenously applied, and the grain filling characteristics and changes in endogenous PA and hormones, i.e., indole-3-acetic acid (IAA), zeatin (Z) + zeatin riboside (ZR), abscisic acid (ABA), ethylene (ETH) and gibberellin 1+4 (GAs), were quantified during wheat grain filling. Exogenous applications of Spd and Spm significantly increased the grain filling rate and weight, but exogenous Put had no significant effects on these measures. Exogenous Spd and Spm significantly increased the endogenous Spd, Spm, Z+ZR, ABA, and IAA contents and significantly decreased ETH evolution in grains. The endogenous Spd, Spm and Z+ZR contents were positively and significantly correlated with the grain filling rate and weight of wheat, and the endogenous ETH evolution was negatively and significantly correlated with the wheat grain filling rate and weight. Based upon these results, we concluded that PAs were involved in the balance of hormones that regulated the grain filling of wheat.