外源过氧化氢对烟草花芽分化的影响初探

通过盆栽试验,对外源H₂O₂处理的烟草活性氧代谢及烟草花芽分化情况进行了初步研究。结果表明：（1）外源H₂O₂处理显著影响了烟草体内活性氧代谢,H₂O₂和O₂ ^-含量迅速增加;保护酶POD和CAT活性迅速被激活,SOD的激活滞后于POD和CAT。喷施H₂O₂处理的中后期H₂O₂的含量下降。（2）外源H₂O₂胁迫改变了开花基因的表达、现蕾时烟草叶片数以及花芽的发育进程。5和15d的外源H₂O₂处理明显抑制了烟草FLC基因的表达,促进了LFY基因的表达,促使烟草花发育提前。试验结果表明烟草体内活性氧平衡状态的变化影响烟草的花发育进程。

Effects of Exogenous Hydrogen Peroxide on Floral Bud Differentiation in Tobacco

The active oxygen metabolism and flower bud differentiation in tobacco were studied by spraying exogenous H₂O₂ via pot experiments. Results showed that: (1) The active oxygen metabolism was significantly changed in tobacco by spraying H₂O₂. After spraying H₂O₂, the content of H₂O₂ and O₂ ^_ was rapidly increased in tobacco, the activities of POD and CAT were rapidly activated followed by the activation of SOD. In the middle and latter period of spraying, the content of O₂ ^_ was high, while the content of H₂O₂ was significantly decreased. (2) The expressions of the floral development genes were affected, the number of leaves in squaring stage was altered and the process of flower bud development was modified by spraying of H₂O₂. The expression of FLC gene was significantly inhibited while the expression of LFY gene was significantly promoted in tobaccos which were sprayed H₂O₂ at 5 and 15 consecutive days. Floral bud differentiation of tobaccos progressed earlier under 5 to 25 consecutive days spray of H₂O₂. The flowering transition was affected by the change of active oxygen equilibrium in tobacco.