水分胁迫下花生根和叶片ABA合成分布差异研究

摘要

以四叶期花生叶片和主根为材料,研究水分胁迫(PEG)和脱落酸(abscisic acid,ABA)生物合成抑制剂Nap(Naproxen)对ABA合成关键限速酶AhNCED1表达、分布及ABA分布和含量的影响.结果显示,根部AhNCED1基因、AhNCED1蛋白在胁迫初期(1 h)即表达增强,此时根部AhNCED1和ABA分布也增强, ABA含量升高.而叶片AhNCED1蛋白表达和分布在胁迫16 h明显增强,同时叶脉ABA免疫信号最强.Nap处理后,根部对水分胁迫快速响应引起AhNCED1蛋白表达和分布增强,ABA分布和含量快速升高;相对应的,叶片维管区域中AhNCED1和ABA分布在胁迫后期(16 h)升高.表明水分胁迫后花生根部和叶片ABA的合成能力与分布存在差异.在根部水分胁迫过程中,2种信号起反应进而引发花生的抗逆反应:通过根快速传递ABA信号和由叶片本身脱水引起ABA的合成和再分布.%The leaves and roots were used to investigate the effects of water stress (PEG) and naproxen (NAP, a potent ABA biosynthesis inhibitor) on expression of AhNCED1 and distribution of ABA in peanut.The results demonstrate that expression level of AhNCED1 gene and AhNCED1 protein are increased at 1 h under water stress, and the distributions of AhNCED1 and ABA are also enhanced, the content of ABA increases in the same time.However, the expression and distribution level of AhNCED1 are increased in leaves at 16 h, and ABA distribution also are enhanced in this time.After Nap treatment and water stress, ABA is synthesized rapidly in vascular parenchyma of root.Oppositely, AhNCED1 and ABA are detected in vascular parenchyma of leaf until 16 h.These resultes indicate that there are different distribution and biosynthesis pattern of ABA in roots and leaves of peanut under water stress.There are two signals of defense responses: 1) fast transfer of ABA signals via root;2) biosynthesis and redistribution of leaves due to dehydration.