TOR dynamically regulates plant cell-cell transport
TOR dynamically regulates plant cell-cell transport
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DOI：
10.1073/pnas.1919196117
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发表时间：
2020-03-03
影响因子：
11.1
通讯作者：
Zambryski, Patricia
中科院分区：
文献类型：
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作者：
Brunkard, Jacob O.;Xu, Min;Zambryski, Patricia
糖从成熟的“源”叶到发育中的“库”叶的协调重新分配需要通过胞间连丝(PD)严格调节细胞间的糖运输。虽然是植物生理学的基础，但控制钯运输从而支持新叶发育的机制仍然难以捉摸。从PD转运改变的正向遗传筛选中，我们发现保守的真核细胞葡萄糖-TOR(雷帕霉素的靶标)代谢信号网络限制了PD在叶片中的运输。促进或破坏TOR活性的遗传途径和化学或生理处理表明，葡萄糖激活的TOR减少了Pd在叶片中的运输。我们进一步发现，在光合作用过量糖的成熟叶片中，TOR活性显著高于年轻的生长叶片，并且这种TOR活性的增加与PD运输速率的降低相关。我们得出结论，叶片细胞调节PD的运输，以响应由TOR途径监测的碳水化合物供应的变化。
The coordinated redistribution of sugars from mature "source" leaves to developing "sink" leaves requires tight regulation of sugar transport between cells via plasmodesmata (PD). Although fundamental to plant physiology, the mechanisms that control PD transport and thereby support development of new leaves have remained elusive. From a forward genetic screen for altered PD transport, we discovered that the conserved eukaryotic glucose-TOR (TARGET OF RAPAMYCIN) metabolic signaling network restricts PD transport in leaves. Genetic approaches and chemical or physiological treatments to either promote or disrupt TOR activity demonstrate that glucose-activated TOR decreases PD transport in leaves. We further found that TOR is significantly more active in mature leaves photosynthesizing excess sugars than in young, growing leaves, and that this increase in TOR activity correlates with decreased rates of PD transport. We conclude that leaf cells regulate PD trafficking in response to changing carbohydrate availability monitored by the TOR pathway.