干旱胁迫下景天植物能量水平与超微弱发光的关系

Relationship between Energy and Ultraweak Luminescence in Sedum hybridum under Drought Stress

该试验以德景天幼苗为材料,设计PEG、PEG+H_2O_2、PEG+苯甲酸钠、蒸馏水(CK)4个处理,分析PEG模拟干旱胁迫及活性氧调控干旱胁迫下超微弱发光(ultraweak luminescence,UWL)和能量水平的变化及两者的关系,为揭示UWL的产生及其来源提供理论依据。结果表明:(1)在PEG模拟干旱胁迫过程中,CK和PEG处理德景天叶片的ATP含量、能荷和UWL强度均随着胁迫时间延长呈下降趋势,但PEG处理的上述指标的下降较CK更快、降幅更大。(2)进一步采用H_2O_2和苯甲酸钠调控活性氧的PEG干旱胁迫过程中,PEG+H_2O_2、PEG+苯甲酸钠处理的德景天叶片ATP含量、能荷和UWL强度的变化趋势与PEG处理基本一致,均随胁迫时间的延长呈下降趋势;但PEG+H_2O_2处理的上述指标均低于PEG处理,而PEG+苯甲酸钠处理的上述指标却高于PEG处理。(3)相关分析表明,在干旱胁迫及活性氧调控干旱胁迫下,德景天叶片UWL强度均与ATP含量和能荷呈显著正相关。研究发现,在干旱胁迫和活性氧调控干旱胁迫下,德景天叶片ATP含量和能荷较CK均明显下降,UWL强度也随之明显降低;UWL强度随着以ATP为代表的能量水平的下降而降低,说明植物中UWL的产生与其能量水平的高低显著相关。

The dynamic variation of ultraweak luminescence（UWL）and energy level,and their relationship under stress of 20% PEG treatment and drought stress with regulating of reactive oxygen by carrying out four treatments of PEG,PEG＋hydrogen（H2O2）,PEG＋sodium benzoate and distilled water（CK）in Sedum hybridumseedling to supply theoretical basis for understanding the generation of UWL.The results showed：（1）in process of drought stress by PEG treatment,ATP content,energy charge and UWL intensity all decreased;above energy index and UWL intensity of PEG treatment decreased more rapidly and showed a bigger drop.（2）Under drought stress with regulating by H2O2 and sodium benzoate,ATP content,energy charge and UWL intensity of treatments of PEG＋H2O2 and PEG＋sodium benzoate all de-creased along with stress time as well as PEG treatment;However,above energy index and UWL intensity of PEG＋H2O2 were lower than those of PEG treatment,while above energy index and UWL intensity of PEG＋ sodium benzoate were higher than those of PEG treatment.（3）Correlation analysis also showed that UWL intensity was positively correlated with ATP content and energy charge both under drought stress and under drought stress with regulation of reactive oxygen.Above results indicated：under drought stress and drought stress with regulation of reactive oxygen,energy level represented by ATP content decreased more rapidly than that of CK,UWL intensity decreased more rapidly than that of CK too;UWL intensity decreased along with the decline of ATP content.which indicated that the generation of UWL in plants positively related to ATP level.