中国农业科学 ›› 2007, Vol. 40 ›› Issue (12): 2780-2787 .

• 土壤肥料·节水灌溉 • 上一篇    下一篇

氯化钾对玉米木质素代谢的影响及其与茎腐病抗性的关系

刘晓燕,金继运,何 萍,高 伟,李文娟   

  1. 中国农业科学院农业资源与农业区划研究所/农业部植物营养与养分循环重点开放实验室
  • 收稿日期:2007-04-05 修回日期:2007-06-26 出版日期:2007-12-10 发布日期:2007-12-10
  • 通讯作者: 金继运

Effect of Potassium Chloride on Lignin Metabolism and Its Relation to Resistance of Corn to Stalk Rot

  

  1. 中国农业科学院农业资源与农业区划研究所/农业部植物营养与养分循环重点开放实验室
  • Received:2007-04-05 Revised:2007-06-26 Online:2007-12-10 Published:2007-12-10

摘要: 【目的】阐明氯化钾(KCl)对玉米木质素代谢的影响,探讨和揭示KCl对提高玉米茎腐病抗性的机制。【方法】通过田间试验与室内分析相结合,研究了KCl对玉米不同抗性品种在接种禾谷镰刀菌(Fursarium graminearum)前后茎基部髓组织木质素含量的影响以及相关酶活性的变化。【结果】抗病品种吉单180茎基部髓组织原生木质素含量低于感病品种吉单327,但诱导木质素高于感病品种;而施用KCl则可降低原生木质素含量,增加诱导木质素含量。抗病品种茎基部髓组织苯丙氨酸解氨酶(PAL)和酪氨酸解氨酶(TAL)活性高峰出现时间均早于感病品种。虽然KCl降低了接种前玉米茎基部PAL、TAL和过氧化物酶(POD)活性的本底值,却提高了接种后PAL、TAL和POD的活性,尤其是高峰值。而且在接种前后,KCl处理的玉米茎基部髓组织肉桂醇脱氢酶(CAD)活性均保持较高水平。【结论】诱导玉米在接种后PAL、TAL、POD和CAD酶系的快速反应,提高诱导木质素含量,进而增强植株对病原菌的抗性,是KCl增强玉米茎腐病抗性的机制之一。

关键词: 氯化钾, 木质素代谢, 酶活性, 玉米茎腐病, 抗性机理

Abstract: 【Objective】This study was to elucidate the effect of potassium chloride (KCl) on lignin metabolism in corn, and discuss the physiological mechanism of KCl suppressing corn stalk rot. 【Method】A field experiment combined with plant analysis experiment was conduct to study the changes in lignin content and activities of phenylalanine ammonia-lyase (PAL), tyrosine ammonia-lyase (TAL), peroxidase (POD) and cinnamyl alcohol dehydrogenase (CAD) in stalk pith tissue of susceptible and resistant corn cultivars before and after inoculation by Fursarium graminearum, and the effect of KCl on the above noted changes. 【Result】The results showed that original content in resistant corn(Jidan180)was lower than that of susceptible corn(Jidan327), while the induced lignin content in resistant cultivar was more than that in susceptible cultivar. And KCl application decreased the original lignin content and increased the induced lignin content. The activities of PAL and TAL in stalk pith tissue were highest at 3 d after inoculation in the resistant cultivar, but increased slowly to a peak at 5 and 7 d after inoculation in the susceptible cultivar, respectively. KCl application decrease the background levels of PAL, TAL and POD activity, while increased the activities of PAL, TAL and POD(especially the maximum activity) in stalk pith tissue of the resistant and susceptible corns following pathogen invasion. In addition, KCl application enhanced CAD activity in the resistant and susceptible corns before and after inoculation. 【Conclusion】In conclusion, KCl stimulated the rapid expression of PAL, TAL, POD and CAD activities in both resistant and susceptible corns after inoculation, increased the induced lignin content, and then enhanced the resistance of corn to stalk rot.

Key words: Potassium chloride, Lignin metabolism, Enzyme activity, Corn stalk rot, Resistance mechanism