摘要
为了解杨树幼苗非结构性碳水化合物(NSC)在干旱胁迫过程中的变化规律及响应机制,通过自然干旱处理,分析随着干旱胁迫加剧叶片水势及不同器官(叶、茎和根)中NSC、可溶性糖和淀粉含量。结果表明:当土壤含水量从田间持水量的100%下降到84%时,叶片和根NSC和可溶性糖含量增加,叶片淀粉含量和水势及茎可溶性糖含量下降;当土壤含水量从田间持水量的84%下降到41%时,叶片和茎NSC含量减少,茎和根可溶性糖/淀粉上升,叶片凌晨水势升高,正午水势降低;当土壤含水量从田间持水量的41%下降到31%时,叶片NSC含量和水势、茎NSC含量及根可溶性糖含量增加,叶片和根淀粉含量降低;当土壤含水量从田间持水量的31%下降到20%时,叶片和茎NSC及淀粉含量降低,叶片可溶性糖含量及水势下降,根NSC含量增加;当土壤含水量从田间持水量的20%下降到16%时,叶片和茎NSC、可溶性糖和淀粉含量升高,根NSC含量和可溶性糖/淀粉及叶片水势降低。可见,杨树幼苗在自然干旱过程中,叶片碳储存下降,根系的碳分配及碳消耗增加;当水力失衡限制了碳运输和代谢时,幼苗可能发生根系碳饥饿而死亡。
In order to understand the changes of non-structural carbohydrates(NSC)in Populus×xiaozhuanica cv.Zhangwu seedlings under drought stress,we analyzed leaf water potential and contents of NSC,soluble sugar,and starch in different organs(leaf,stem,and root)with intensified drought conditions.The results showed that the contents of NSC and soluble sugar in leaves and roots increased,and starch content and water potential in leaves and soluble sugar content in stems decreased when soil water content dropped from 100%to 84%of field water-holding capacity.NSC contents in leaves and stems decreased and the ratio of soluble sugar to starch in stems and roots increased,while leaf water potential increased at predawn and decreased at midday when soil water content dropped from 84%to 41%of field water-holding capacity.Leaf NSC content and water potential,stem NSC content,and root soluble sugar content increased,while leaf and root starch contents decreased when soil water content dropped from 41%to 31%of field water-holding capacity.NSC and starch contents in leaves and stems,and leaf soluble sugar content and water potential decreased,whereas root NSC content increased when soil water content dropped from 31%to 20%of field water-holding capacity.Contents of NSC,soluble sugar and starch in leaves and stems increased,whereas root NSC content and ratio of soluble sugar to starch,and leaf water potential decreased when soil water content dropped from 20%to 16%of field water-holding capacity.Our results indicated that P.×xiaozhuanica cv.Zhangwu seedlings would decrease leaf carbon storage but increase root carbon distribution and carbon consumption under natural drought.When hydraulic imbalance limits carbon transport and metabolism,seedlings may die due to root carbon starvation.
作者
王凯
逄迎迎
吕林有
张大鹏
焦向丽
WANG Kai;PANG Ying-ying;LYU Lin-you;ZHANG Da-peng;JIAO Xiang-li(College of Environmental Science and Engineering,Liaoning Technical University,Fuxin 123000,Liaoning,China;Liaoning Institute of Sandy Land Control and Utilization,Fuxin 123000,Liaoning,China;Hubei Province Engineering Consulting Co.,Ltd,Wuhan 430071,Hubei,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2021年第7期1969-1978,共10页
Chinese Journal of Ecology
基金
国家自然科学基金项目(31400613)
辽宁省“兴辽英才计划”项目(XLYC1807017)资助。
关键词
干旱致死
器官差异
水力失衡
碳饥饿
阶段性响应
drought-induced mortality
organ difference
hydraulic failure
carbon starvation
staged response