摘要
通过对拟南芥NCED3、AAO3及SDR1蛋白亚细胞定位分析及根系和叶片ABA池的动态库变化研究,结果表明气孔运动的有效ABA信号来自于保卫细胞之外,SDR与ABA前体加工和运输有关。胁迫处理后根系合成酶基因转录水平显著高于叶片,但叶片ABA水平是根系的10倍以上,离体叶片和附体叶片ABA含量测定表明,叶片ABA池的形成主要决定于根源ABA的输入。氟啶酮药剂阻断和遮荫实验说明根系ABA池受叶源类胡萝素前体供应影响。叶片ABA水平受根源ABA和叶源类胡萝素前体库双向转运调节,维管束组织系统可能协同和整合了这一复杂调节机制。该结论为逆境ABA信号转递机制研究和操纵内源ABA含量增强植物抗逆性的应用提供相关资料。
Subeellular localization of AtNCED3, AtAAO3 and AtSDR1 proteins, and dynamic changes of ABA levels in root and leaf were investigated in the present study. Results showed that the guard cells were not the main site of ABA biosynthesis, and SDR might play an important role in ABA precursor processing and transportation. The transcription level of ABA synthase gene in roots was significantly higher than that in leaves under dehydration condition, while the ABA concentration in leaf tissues were 10 times higher than root. Detection of ABA concentration in both detached leaves and attached leaves suggested that ABA accumulation in leaves was mainly derived from root-sourced ABA, it was confirmed that ABA synthesis in roots was affected by the supply of precursor carotenoids with the fluridone treatment and shading experiments. These data revealed that ABA levels in leaves were regulated by root-sourced ABA transportation and leaf-sourced carotenoids supply. Our present results showed that vascular system might be involved in the coordination and integration of this complex regulatory mechanism for ABA signal accumulation. The conclusion provided relevant information for exploring molecular mechanism of stress signal transduction, manipulating endogenous ABA levels, and enhancing plants resistance against environmental stresses.
出处
《云南植物研究》
CSCD
北大核心
2009年第4期344-352,共9页
Acta Botanica Yunnanica
基金
福建省自然科学基金(B0810040)
福建省教育厅A类科技项目(JA08154)资助
