Development of a quantitative tool for measuring changes in the coefficient of conductivity of plasmodesmata induced by developmental, biotic, and abiotic signals
Development of a quantitative tool for measuring changes in the coefficient of conductivity of plasmodesmata induced by developmental, biotic, and abiotic signals
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DOI：
10.1007/s00709-004-0079-x
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发表时间：
2005-04-01
期刊：
影响因子：
2.9
通讯作者：
Epel, BL
中科院分区：
文献类型：
--
作者：
Liarzi, O;Epel, BL
细胞间和器官间通讯的调控是植物发育过程中细胞命运决定的关键，可能在基因表达的系统调控以及对病原体或其他生物和非生物环境因素的防御反应中起着重要作用。在植物中，共质细胞与细胞之间的通讯是由胞间连丝（Pd）提供的，胞间连丝是一种同轴的膜通道，跨越细胞壁将相邻的细胞壁相互连接。大分子、蛋白质和RNA可通过被动扩散或易化机制通过Pd转运。开发了一种定量工具来测量传导系数C（Pd），用于通过Pd的扩散驱动运输，并评估由发育，生物和非生物信号引起的系数变化。C-GFP（Pd），绿色荧光蛋白（GFP）（Stokes半径为2.82 nm的蛋白质）的细胞间扩散的传导系数，在表达烟草花叶病毒（MPTMV）的运动蛋白的野生型和转基因本塞姆氏烟草植物的库叶和源叶的表皮细胞中测定，所述库叶和源叶在黑暗和光照下以及在16和25 ℃下孵育。在所有条件下，源叶中的Pd都能传导大分子，且C-GFP（Pd）（汇）> C-GFP（Pd）（源）。光下调C-GFP（Pd）（所有条件）;下调对于汇细胞更强。MPTMV对表皮细胞之间C-GFP（Pd）的影响依赖于温度和叶片发育;在16 ℃下，MPTMV仅在源叶中下调C-GFP（Pd），而在25 ℃下，MPTMV没有显著影响。这种定量工具应该是有用的研究突变或沉默诱导的Pd电导率的差异。
The regulation of intercellular and interorgan communication is pivotal for cell fate decisions in plant development and probably plays a significant role in the systemic regulation of gene expression and in defense reactions against pathogens or other biotic and abiotic environmental factors. In plants, symplasmic cell-to-cell communication is provided by plasmodesmata (Pd), coaxial membranous tunnels that span cell walls interconnecting adjacent cytoplasms. Macromolecules, proteins, and RNA may be transported through Pd by passive diffusion or by a facilitated mechanism. A quantitative tool was developed to measure the coefficient of conductivity, C( Pd), for diffusion-driven transport via Pd and to assess changes in the coefficient induced by developmental, biotic and abiotic signals. C-GFP(Pd), the coefficient of conductivity for cell-to-cell spread of green-fluorescent protein (GFP), a protein with a Stokes radius of 2.82 nm, was determined in epidermal cells of sink and source leaves of wild-type and transgenic Nicotiana benthamiana plants expressing the movement protein of tobacco mosaic virus (MPTMV) incubated both in dark and light and at 16 and 25 degrees C. Under all conditions, Pd in source leaves conducted macromolecules, with C-GFP(Pd)(sink) > C-GFP(Pd)(source). Light down-regulated C-GFP(Pd) ( all conditions); down-regulation was stronger for sink cells. The effect of MPTMV on C-GFP( Pd) between epidermal cells was dependent on temperature and leaf development; at 16 degrees C, MPTMV down-regulated C-GFP(Pd) only in source leaves, while at 25 degrees C, MPTMV had no significant effect. This quantitative tool should be useful for investigating differences in Pd conductivity that are induced by mutations or silencing.