【作者】 张瑞霞；

【导师】 汪耀富；

【作者基本信息】 河南农业大学 ， 作物栽培学与耕作学， 2004， 硕士

【摘要】 植物激素和多胺均属植物生长调节物质，它们在很低浓度下可促进或抑制或改变植物的发育进程。在植物受到胁迫时，植物激素和多胺一般是通过浓度的改变来调节植物的生长发育和形态建成。本文采用水培试验，以聚乙二醇为渗透剂，研究了渗透胁迫和不同氮肥形态对烟叶内源激素和多胺含量的影响，并采用土培试验探讨了外施多胺对水分胁迫下烟叶多胺含量及其代谢酶活性的调节作用，主要研究结果如下： （1）随渗透胁迫时间延长和胁迫程度的增加，烤烟叶片脱落酸（ABA）含量增加，生长素（IAA）、赤霉素（GA₃）和玉米核苷（iPA）含量的变化特点为先降低，随后升高，到一定程度又降低。渗透胁迫下烤烟根系ABA含量迅速积累，IAA、GA₃和iPA含量仅在渗透势为-0.25Mpa时上升。渗透胁迫使烤烟叶片和根系多胺含量都呈现先增加后降低的动态变化，并且随渗透势降低其变化幅度增大。渗透胁迫可以提高烟叶精氨酸脱羧酶（ADC）和多胺氧化酶（PAO）活性，降低鸟氨酸脱羧酶（ODC）活性，且叶片PAO活性的提高与多胺含量积累几乎同步。 （2）渗透胁迫和不同氮肥形态处理烤烟叶片内源激素和多胺含量有明显的差异。在非胁迫条件下铵态氮处理烟叶中脯氨酸（PRO）和ABA、GA₃含量较高，IAA含量较低；硝态氮处理则相反；硝态氮+铵态氮处理可以提高烟叶玉米素核苷（ZR）含量。在渗透势为-0.3Mpa的渗透胁迫下，各种形态氮肥处理烟叶中PRO含量都显著增加；铵态氮和硝态氮处理烟叶中ABA含量有升高的趋势，IAA和GA₃含量明显下降；硝态氮+铵态氮处理烟叶中各种激素含量都有不同程烤烟激素与多胺对水分胁迫和氮肥形态的响应及其调节研究度增加。随胁迫程度增大，按态氮处理烟叶PRO含量显著降低，GA3和ZR含量明显增加，ABA和IAA含量变化不大;硝态氮处理烟叶PRO含量持续增加，各种激素含量变化幅度都较小;硝态氮+钱态氮处理烟叶PRO和ABA，GA3，zR含量有所降低，IAA含量变化不明显。不同氮肥形态相比较，铰态氮处理烟叶的烟碱含量最高，而硝态氮+钱态氮处理烟叶多胺含量最高;在渗透胁迫下，烟叶中烟碱和多胺含量都不同程度增加，其中硝态氮十钱态氮处理增加幅度最大，钱态氮处理次之，硝态氮处理增加幅度最小;另外，在渗透胁迫下，硝态氮处理烟叶中腐胺/（亚精胺+精胺）[Pu灯（sPd+s pm）」比值较小，表明硝态氮处理的烟株抗渗透胁迫能力较强。 （3）在非水分胁迫条件下外源喷施多胺可以提高烟叶烟碱含量，但在水分胁迫下，喷施多胺烟叶烟碱含量降低。干旱胁迫下叶面喷施多胺可以增强烟叶精氨酸脱梭酶（ADC）、鸟氨酸脱梭酶（ODC）活性，阻遏可溶性蛋白质含量的下降。在水分胁迫下，喷施腐胺(Put、亚精胺会降低烟叶Put、spd含量，而喷施精胺则能提高上部叶put、spd和sPm含量，同时put/（sPd+s pm）比值大幅度降低，说明外源多胺可提高烟草的抗旱能力。更多还原

【Abstract】 Phytohormone and polyamine are belong to plant growth regulators. They can accelerate or restrain or change plant growth course at very low density When plants get menaced, phytohormone and polyamine commonly adjust the growth and form build of plant by changing their density. This paper studied the effect of osmotic stress on endogenous hormone and polyamine content in flue-cured tobacco under nitrogen forms by hydrocultivate examination using PEG(6000) as infiltrator,and discussed the effect of external polyamine on endogenous polyamine content and activities of their metabolize enzyme under drought press. The result as follows:(1).There was significant effect of osmotic stress on the changes of endogenoushormone and polyamine content .With the osmotic stress time prolonging and menace degree increasing,the content of abscisic acid (ABA) in flue-cured tobacco leaves increased,but the changes of heteroauxin (IAA), gibberellin (GA3) and iPA are falling at first, increasing after that and falling again to a certain stress.The content of ABA in flue-cured tobacco roots rapid accumulate under osmotic stress,but the content of IAA GA3 and iPA increased only under -0.25Mpa.The contents of polyamine in flue-cured tobacco leaves and roots increased at first and then failed under osmotic stress,and the range of their change was largen with osmotic potential falling.Osmotic stress can heighten the activities of ADC and PAO and decrease the activities of ODC in flue-cured tobacco leaves,even the increase of the activities of PAO is almost in-phase with the accumulation of polyamine content.(2).There are obvious difference in the contents of endogenous hormone and polyamine content under osmotic stress and different nitrogen forms.The content of PRO, ABA and GA3 in the leaves was higher and the content of IAA was lower when tobacco was fertilized with ammonium (NH4-N) than that of nitrate (NO3-N) without osmotic stress, and that the content of ribosylzeatin (ZR) was increased when tobacco was fertilized with ammonium + nitrate (NO3-N + NH4-N). It was observed that allthe nitrogen forms could significantly increase the content of PRO in the leaves under osmotic stress when the osmotic potential was at -0.3MPa. At the same time, the content of ABA tended to raise, and the content of IAA, GA3 and ZR obviously decreased respectively when tobacco fertilized with both NH4-N and NO3-N, while the content of all the endogenous hormones determined were increased in varying degrees when tobacco was fertilized with NO3-N + NH4-N. With the increasing of osmotic stress, it was found that NH4-N could significantly decline the content of PRO, and increase the content of GA3 and ZR, but had not significant effect on the changes of ABA and IAA, and NO3-N did not significantly affect the changes of endogenous hormones in tobacco leaves though the content of PRO could be increased continuously. It was also found that the content of PRO, ABA, GA3 and ZR could be decreased by NO3-N + NH4-N, but no significant change on IAA was observed. The content of nicotine in flue-cured tobacco leaves is the highest under fertilized with NH4-N,but the content of polyamine is the highest under fertilized with NO3-N + NH4-N.The content of nicotine and three polyamines are increasing with different degrees under osmotic stress and different nitrogen forms,thereinto the change scope under fertilized with NO3-N + NH4-N is bigger than that under fertilized with NH4-N,and the change scope under fertilized, with NO3-N is the least.On the side,the ratio of put/ (spd+spm) is smaller under fertilized with N03-N,we can presume that the tobacco under fertilized with NO3-N has obvious ability to resist osmotic stress.(3).There is significant effect of external polyamine on endogenous polyamine content and activities of their metabolize enzyme in tobacco leaves under drought press, external polyamines promote the synthesize of nicotine in tobacco leaves under no water stress,but decrease the content under water press, external polyamine can engance the a更多还原