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.

The relationship of between release of ethylene and concentration of polyamines and the accumulation of reactive oxygen in Peganum multisectum Bobr leaves under drought stress

We have studied the dynamic changes of the ethylene release, the polyamine concentrations, the reactive oxygen accumulation, and the permeability of plasma membrane in Peganum multisectum leaves under drought stress using pot culture experiment. The concentration of malondialdehyde (MDA) and the permeability of plasma membrane in P. multisectum leaves increase with the increase of the drought stress and the length of stress time. Under light drought, the rate of ethylene production, the concentration of putrescine (Put), spermine (Spm), spermidine (Spd), O-•2, H2O2 and MDA, as well as the activity of polyamine oxidase (PAO) have no significant changes with the increase of the length of stress time. At the early stage (0-30 days) of moderate and heavy drought, the concentration of Put, Spm, and Spd increases abruptly, the rate of ethylene production decreases, and the concentration of O-•2, H2O2, and MDA and PAO activity in P. multisectum leaves keep almost unchanged. While at 45-75 days, on the contrary, the concentration of Put, Spm and Spd decreases, and the concentration of O-•2, H2O2,and MDA increases substantially. The permeability of plasma membrane and the rate of ethylene production also increase. The release of ethylene has strong correlation with the concentration of O-•2and H2O2 in P. multisectum leaves. It indicates that under moderate and heavy drought, the production of ethylene and polyamine constrains each other in P. multisectum leaves, the accumulation of O-•2, H2O2 induced by the increase of ethylene release results in the abrupt increase of the permeability of plasma membrane.