外源Ca2+对高温强光胁迫下滨梅幼苗的保护效应

以10 mmol/L CaCl2溶液处理滨梅幼苗叶片后,置于培养箱于(40±2)℃高温、光照强度(1 200±50)μmol·m-2·s-1下培养,定期测定有关生理生化指标,以探讨外源Ca2+对高温强光胁迫下滨梅幼苗的保护效应.结果显示:(1)与蒸馏水处理组相比,Ca2+处理使高温强光胁迫下滨梅幼苗叶片的脯氨酸含量显著升高,可溶性糖含量变化不明显,根系活力小幅降低;Ca2+处理有效抑制了高温强光下膜透性的加大,提高和保护了Ca2+-ATPase的活性.(2)采用Ca2+螯合剂EGTA或钙调素拮抗剂TFP对滨梅幼苗叶片同法处理并同条件胁迫时,与Ca2+处理相比,滨梅幼苗的脯氨酸、可溶性糖含量、Ca2+-ATPase活性和根系活力均明显下降,膜透性加大.研究表明,Ca2+处理能提高滨梅幼苗对高温强光的耐受性;Ca2+信号系统参与了胁迫过程中的渗透物质和Ca2+-ATPase活性等的调节.

Protective Effect of Exogenous Ca~(2+) on Beach Plum Seedlings under High Temperature and Strong Light Stress

After being sprayed with 10 mmol/L CaCl2,beach plum seedlings were cultured at(40±2)℃ in incubator,and the light intensity being(1 200±50) μmol·m-2·s-1,the correlative physiological indexes were measured regularly.The results show that:Ca2+ could evidently increace the content of proline and decrease root activity.It also shows that:Ca2+ could effectively inhibit cell membrane permeability increase the activity of Ca2+-ATPase.Moreover,addition of Ca2+ chelating agent EGTA or calmodulin antagonist TFP could markedly decrease the content of proline,soluble sugar,root activity,and the activity of Ca2+-ATPase.It also shows that:EGTA and TFP could obviously facilitate cell membrane permeability increase.Taken together the above results,it is suggested that Ca2+ could improve high temperature and strong light tolerance of beach plum seedlings and Ca2+ signal system may be regulated by change of some osmolytes and the activity of Ca2+-ATPase in beach plum seedlings under high temperature and strong light.