| 摘要: |
| [目的]揭示干湿交替环境下植物或栽培作物发生补偿效应的生理学机制,为现代生物学节水的实践研究以及植物抗旱机制的理论研究提供理论依据.[方法]在琼脂-聚乙二醇(Agar-PEG)培养介质中,从根系结构变化、C、N代谢、渗透调节以及活性氧防御系统的优化等方面,对旱后复水诱导玉米根系功能发生补偿效应的生理学机制进行初探.[结果]干旱胁迫下玉米根系活力明显减弱,而复水后,随着复水时间的推移,诱发出大量的新侧根和根毛,代谢功能增强,补偿或部分补偿了干旱胁迫造成的危害.可溶性糖在体内进行了重新分配,运往根系的可溶性糖显著增多.除Gly和Ala含量在干湿交替处理和干旱胁迫处理中无差异外,复水处理的其他游离氨基酸及其总量均介于-直胁迫和一直湿润处理之间,而且两两间的差异达显著水平.复水处理在维持根系较低的O2-和H2O2含量的同时,提高了SOD和CAT的活性,减小了膜脂过氧化危害和离子泄露,具有预警作用.[结论]旱后复水玉米光合产物向根系的重新分配、Pro和其他游离氨基酸含量的增加、活性氧清除和防御系统的优化、以及新生侧根和根毛的形成,可能正是干湿交替水环境下玉米根系功能产生补偿效应的生理学基础. |
| 关键词: 玉米 干湿交替 新生细根 相溶性溶质 补偿效应 |
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| 基金项目:国家高技术研究计划项目（2006AA100218）;教育部新世纪优秀人才项目;西北农林科技大学专项基金项目 |
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| Studies on the physiological mechanism of functional compensation effect in maize root system induced by re-watering after draught stress |
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| Abstract: |
| 【Objective】 It has a great practical and theoretical meaning to explore the compensation mechanism resulted from dry-wet-alteration water conditions.【Method】Under Agar-PEG conditions,the compensation mechanism of maize root function at root system architecture,C and N metabolism and enzyme defense system were studied. 【Result】The results showed that the active root genesis was induced gradually.Under water-stress conditions the root activity reduced.After re-watering,a great deal of new lateral roots and root hairs were induced,the root activity recovered gradually,and compensated or partially compensated the adverse effect induced by water stress.Furthermore,the soluble carbohydrate was rearranged:the percent in root system was obviously higher than that in both water-stress treatment and control.Except for Gly and Ala,the contents of other single amino acid as well as total amino acids in dry-wet alteration treatment were between water-stress treatment and control.It also illustrated that the dry-wet alteration treatment increased both SOD and CAT activity while maintaining a lower O2- and H2O2 content.【Conclusion】 It is concluded that the soluble carbohydrate rearrange mentin root,the increase of Proline and other free amino acids content,new lateral root and root fair initiation,and enzyme defense system optimization may be the mechanism for compensation effect under dry-wet alteration treatment. |
| Key words: maize re-watering active root compatible solute compensative effect |
