n nnnDamage induces remote occlusion of sieve tubes in Vicia fababy forisome dispersion, triggered during the passage of an electropotentialwave (EPW). This study addresses the role of Ca2+ channels andcytosolic Ca2+ elevation as a link between EPWs and forisomedispersion. Ca2+ channel antagonists affect the initial phaseof the EPW as well as the prolonged plateau phase. Resting levelsof sieve tube Ca2+ of 50 nM were independently estimated usingCa2+-selective electrodes and a Ca2+-sensitive dye. Transientchanges in cytosolic Ca2+ were observed in phloem tissue inresponse to remote stimuli and showed profiles similar to thoseof EPWs. The measured elevation of Ca2+ in sieve tubes was belowthe threshold necessary for forisome dispersion. Therefore,forisomes need to be associated with Ca2+ release sites. Wefound an association between forisomes and endoplasmic reticulum(ER) at sieve plates and pore-plasmodesma units where high-affinitybinding of a fluorescent Ca2+ channel blocker mapped an increaseddensity of Ca2+ channels. In conclusion, propagation of EPWsin response to remote stimuli is linked to forisome dispersionthrough transiently high levels of parietal Ca2+, release ofwhich depends on both plasma membrane and ER Ca2+ channels.展开▼
机译:ABSTRACTn FONT> TH> TR> TABLE> n
n TOP n <字体颜色= 464c53>抽象 FONT> n 介绍 n 结果 n 讨论 n 方法 n 参考文献 n FONT> TH> TR> TABLE> n nnnDamage导致蚕豆 I> SUP>中的筛管远程阻塞由电势 SUP>波(EPW)通过时触发的分散。这项研究探讨了Ca 2 + SUP>通道和 SUP>胞质Ca 2 + SUP>升高作为EPW与主要 SUP之间的联系的作用。 >分散。 Ca 2 + SUP>通道拮抗剂会影响EPW的初始阶段 SUP>以及延长的高原期。 50 nM的筛管Ca 2 + SUP>的静置水平 SUP>独立使用 SUP> Ca 2 + SUP>选择电极和Ca 2 + SUP>敏感染料进行估算。在韧皮部组织中, SUP>对远程刺激的反应中,细胞质中Ca 2 + SUP>的瞬时 SUP>发生了变化,并且与 SUP相似> EPW。在筛管中测得的Ca 2 + SUP>的高度低于 SUP>分散所需的阈值。因此, SUP>异构体需要与Ca 2 + SUP>释放位点相关。我们 SUP>在筛板和孔-等离子胞浆单元处发现了形态和内质网 SUP>(ER)之间的关联,其中荧光Ca的高亲和力 SUP>结合 2 + SUP>通道阻滞剂映射了Ca 2 + SUP>通道增加的 SUP>密度。综上所述,EPWs SUP>的繁殖是通过瞬时高水平的顶叶Ca 2 + SUP>,释放< SUP> SUP>取决于质膜和ER Ca 2 + SUP>通道。 SUP>
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