不同抗性烟草品种内源激素对赤星病胁迫的响应差异

为进一步明确烟株内源激素与赤星病抗性的关系，以抗赤星病烟草品种净叶黄和感病品种长脖黄为研究对象，通过盆栽种植并接种赤星病菌，比较不同抗性品种内源激素含量对赤星病胁迫的响应差异。研究结果显示，在赤星病胁迫下，净叶黄、长脖黄的脱落酸（ABA）含量和乙烯（ET）释放量均呈上升趋势，而生长素（IAA）以及细胞分裂素（CTK）含量表现为降低。同时，赤星病胁迫导致净叶黄的赤霉素（GA）、茉莉酸（JA）含量增加，引起长脖黄的JA含量降低，GA含量则先增加后降低。与净叶黄相比，长脖黄的ABA含量增幅较小，而GA、IAA、CTK与JA含量降幅较大，并且ET释放量较高。综上，在赤星病胁迫下，内源激素的含量差异以及变化幅度可以反映不同品种的抗病能力。

Difference of Endogenous Hormones in Tobacco Resistant and Susceptible Cultivars in Response to Brown Spot Infection

The purpose of this present study was to thoroughly analysis the correlation between endogenous hormones in tobacco plants and the level of resistance to tobacco brown spot. Under pot experiment, two tobacco cultivars with different resistance levels, JYH (resistant cultivar) and CBH (sensitive one) were inoculated with tobacco brown spot to check the changes of endogenous hormones due to brown spot infection. The results showed that the contents of endogenous hormones in the two cultivars were influenced by tobacco brown spot infection, and there were obviously different changes in the two cultivars. The abscisic acid (ABA) contents and ethylene (ET) production amount in the two cultivars had a general uptrend in response to tobacco brown spot infection. By contrast, the contents of indole-3-acetic acid (IAA) and cytokinins (CTK) both declined in some degrees. Moreover, tobacco brown spot infection increased the contents of gibberellin (GA) and jasmonate (JA) in JYH, while in CBH, the GA contents increased initially and then declined, and the JA contents continuously declined under stress. Compared with JYH, the content of ABA in CBH increased less, while the contents of GA, IAA, CTK and JA decreased more, and the released amount of ET was higher. In conclusion, the contents and changes of endogenous hormone can reflect the resistance of different varieties to brown spot.