增塑剂对小麦种子萌发过程中细胞程序性死亡指标的影响

为了明确增塑剂与细胞程序性死亡(PCD)的关系,用邻苯二甲酸酯类增塑剂处理小麦种子,研究增塑剂对小麦种子萌发过程中细胞程序性死亡相关指标的影响,并对增塑剂诱导细胞程序性死亡的生理生化和分子机制进行了初步探讨.结果表明,增塑剂对小麦种子萌发率有显著影响,能够抑制小麦种子萌发.增塑剂处理后小麦种子萌发过程中超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性先上升后下降,同时实验后期抗坏血酸过氧化物酶(APX)活性也有类似的趋势.经DNA ladder实验证明,高浓度增塑剂处理能够引发小麦种子细胞程序性死亡.其原因可能与增塑剂促进gr、dhar以及vpe、metacaspase基因的表达有关,且随着增塑剂浓度的不断增大,各基因相对表达量变化趋势基本一致.

Mechanism of the Programmed Cell Death Triggered by Plasticizers in the Germination Process of Wheat Seeds

Based on the considerations of possible adverse effects caused by the development of biological technology, biology security has increasingly been the focal issue concerned at home and abroad. In this research, phthalic acid esters (PAEs) were used to treat the seeds of Triticum aestivum so as to study its effects on the seeds germination, including physiological changes and molecular mechanisms, which might undergo the progress of programmed cell death (PCD) after being treated with PAEs. The results showed that the germination rate of the wheat seeds was highly affected by different concentrations of PAEs and with the increase of the concentrations of PAEs, the germination rate showed a decreasing trend. The changes on the activities of reactive oxygen species (ROS), superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) in the ROS pathway of the seeds treated with different concentrations of PAEs at different times, indicated that the activities of SOD and CAT increased at first and then declined, meanwhile, the activity of APX showed a similar trend in the later growth period. The experiment of DNA ladder certified that PAEs at high concentration could cause the Programmed cell death of the seeds. The quantitative expression analysis of the relative genes after PAEs revealed that PAEs could promote the expression of the genes of gr, dhar, vpe and metacaspase, and with theincrease of PAEs, the trends of the relative expression of each gene were basically consistent.