渗透胁迫下烤烟根和叶片中内源激素含量的变化

采用酶联吸附免疫测定(ELISA)技术分析了渗透胁迫下烤烟根和叶片中脱落酸(ABA)、生长素(IAA)、赤霉素(GA3)和异戊烯基腺嘌呤(iPA)4种内源激素含量的变化。结果表明,渗透胁迫下烤烟叶片水势降低,蛋白质含量增加,根和叶中ABA和iPA含量升高,IAA和GA3含量减少。培养液渗透势-0.5 MPa与-0.25 MPa两处理相比,前者烟叶水势和ABA含量较低,蛋白质及IAA、GA3和iPA含量较高,根中iPA和叶中ABA含量达到高峰及根中GA3含量出现低谷所需时间较短,其它指标的变化二者同步。根与叶中激素含量相比,在胁迫处理前期(6 h)根中IAA和GA3含量的降低幅度较大,ABA含量峰值出现较早,说明烤烟根中的激素对渗透胁迫的反应更加敏感。

Changes of Endogenous Phytohormones Content in Root and Leaf of Flue-cured Tobacco Under Osmotic Stress

The method of enzyme-linked immunosorbant assay(ELISA) was employed to determine the changes of abscisic acid(ABA),indoleacetic acid(IAA),gibberellin(GA_3) and zeatin(iPA) contents in flue-cured tobacco roots and leaves under osmotic stress.The results showed that leaf water potential declined and leaf protein content increased under osmotic stress.It was also found that the content of ABA and iPA in the roots and leaves was increased and that of IAA and GA_3 was decreased significantly.Lower leaf water potential and ABA content and higher content of protein and IAA,GA_3,iPA in the leaves of plants treated with solute osmotic potential at-0.5 MPa was observed as compared to those with solute osmotic potential of-0.25 MPa.Moreover,the time was shorter for the former treatment when iPA content in roots and ABA content in leaves reached the peak,while GA_3 concentration in roots declined to the valley.However,the changes of the other indices in roots and leaves were synchronous.The results also showed that the decrease of IAA and GA_3 content in the roots was more significant and the increase of ABA content was more rapid as compared with the leaves at the early stress stage(6 h).It suggested that the response of endogenous phytohormones in flue-cured tpbacco roots to osmotic stress was more susceptible than that in the leaves.