Leaf-to-shoot apex movement of symplastic tracer is restricted coincident with flowering in Arabidopsis
Leaf-to-shoot apex movement of symplastic tracer is restricted coincident with flowering in Arabidopsis
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DOI：
10.1073/pnas.251675698
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发表时间：
2002-02-05
影响因子：
11.1
通讯作者：
Zambryski, P
中科院分区：
文献类型：
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作者：
Gisel, A;Hempel, FD;Zambryski, P
植物生理学的经典实验表明，叶子是控制茎分生组织花朵发育的信号来源。其他生理和遗传实验表明，一些分子（例如赤霉素、细胞分裂素和蔗糖）可以促进芥菜（包括拟南芥）开花。这些小的亲水分子可能通过韧皮部和/或通过胞间连丝的细胞间运动共塑性地移动到茎尖。为了分析拟南芥开花诱导过程中小分子共质运输的潜在变化，我们测量了从叶子到茎尖的共质示踪剂流动的变化。我们之前发现开花的开始与共质示踪分子从叶到芽的运输明显减少同时发生。这种贩运量的减少是暂时的，当花卉发展成熟后就会恢复。在这里，我们通过监测不同光周期诱导条件下和许多开花时间改变的遗传背景下的示踪剂运动，对花诱导过程中的共质体连通性进行了详细分析。在所有情况下，开花与共质示踪剂运动减少之间的相关性都是成立的。在开花诱导期间缺乏示踪剂运动可能代表此时胞间连丝选择性的变化或共体共体减少的时期。阳离子与花诱导有关。
Classical experiments in plant physiology showed that leaves are the source of signals that control the development of flowers from shoot meristems. Additional physiological and genetic experiments have indicated some of the molecules (e.g., gibberellins, cytokinins, and sucrose) that promote flowering in mustards including Arabidopsis. These small hydrophilic molecules are likely to move to the shoot apex symplastically via the phloem and/or via cell-to-cell movement through plasmodesmata. To analyze potential changes in the symplastic trafficking of small molecules during the induction of flowering in Arabidopsis, we measured changes in the flow of symplastic tracers from the leaf to the shoot apex. We previously found that the onset of flowering is coincident with an evident decrease in the leaf-to-shoot trafficking of symplastic tracer molecules; this decrease in trafficking is transitory and resumes when floral development is established. Here we provide detailed analyses of symplastic connectivity during floral induction by monitoring tracer movement under different photoperiodic induction conditions and in a number of genetic backgrounds with altered flowering times. In all cases, the correlation between flowering and the reduction of symplastic tracer movement holds true. The lack of tracer movement during the induction of flowering may represent a change in plasmodesmal selectivity at this time or that a period of reduced symplastic communi. cation is associated with floral induction.