东北山樱根浸提液对幼苗生长和根系呼吸代谢的影响

以东北山樱(Cerasus sachalinensis Kom.)为试材,研究其根浸提液对幼苗生长及根系呼吸代谢的影响。结果表明,东北山樱根浸提液对幼苗株高、茎粗、发根数量、茎叶和根的生长量、根系活力、PSⅡ最大光化学效率及呼吸底物含量均表现出低促高抑的化感作用效果。100 g.L-1质量浓度处理对呼吸速率、呼吸途径、呼吸酶活性和中间代谢产物均无显著影响,呼吸代谢顺利进行;200 g.L-1质量浓度使呼吸速率显著升高,激活了HK、PK和G-6-PDH的活性,降低了MDH的表达量,TCA受到抑制,丙酮酸积累,幼苗表现出一定的逆境胁迫状态;400 g.L-1质量浓度使根系呼吸速率下降42.82%;G-6-PDH和6-G-PDH的活性显著提高,调控PPP大量运行,EMP-TCA受阻,丙酮酸和柠檬酸含量显著下降,幼苗呼吸代谢过程紊乱。

Effects of aqueous root extracts on seedling growth and root respiratory metabolisms of Cerasus sachalinensis

The effects of aqueous extracts of Cerasus sachalinensis Kom.roots on seedling growth and root respiratary metabolisms were studied.Results showed that the seedling height,stem diameter,root length,new root number,growth of shoot and root,root activity,the PSⅡ maximum photochemical efficiency and respiratory substrate content of C.sachalinensis were all stimulated at low concentration and repressed at high concentration.The respiratory rates,respiratory pathways,respiratory enzyme activities and intermediate products were not significantly influenced at 100 g·L-1 concentration and the respiratory metabolism had done successfully.Respiratory rate was notablely increased at 200 g·L-1 concentration.The HK,PK and G-6-PDH activities were induced and MDH expression were depressed.Seedlings were under stress as a result of TCA process choked back and pyruvic acid accumulated.Treatment of 400 g·L-1 concentration checked the respiratory rate greatly by 42.82%,the G-6-PDH and 6-G-PDH activities were significantly enhanced which regulated PPP running at high level but EMP-TCA suffocated.Contents of pyruvic acid and citric acid declined greatly and the seedling respiratory metabolisms disordered.