1] Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China [2] Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4.
Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4.
Nat Commun. 2014;5:3090. doi: 10.1038/ncomms4090.
Stomata are two-celled valves that control epidermal pores whose spacing optimizes shoot-atmosphere gas exchange. They develop from protodermal cells after unequal divisions followed by an equal division and differentiation. The concentration of the hormone auxin, a master plant developmental regulator, is tightly controlled in time and space, but its role, if any, in stomatal formation is obscure. Here dynamic changes of auxin activity during stomatal development are monitored using auxin input (DII-VENUS) and output (DR5:VENUS) markers by time-lapse imaging. A decrease in auxin levels in the smaller daughter cell after unequal division presages the acquisition of a guard mother cell fate whose equal division produces the two guard cells. Thus, stomatal patterning requires auxin pathway control of stem cell compartment size, as well as auxin depletion that triggers a developmental switch from unequal to equal division.
气孔是控制表皮孔的双细胞阀，其间距优化了芽 - 大气气体交换。它们是在不等分裂后进行等分裂和分化，从原表皮细胞发育而来的。激素生长素的浓度，一种主要的植物发育调节剂，在时间和空间上受到严格控制，但它在气孔形成中的作用尚不清楚。在这里，通过延时成像，使用生长素输入（DII-VENUS）和输出（DR5：VENUS）标记物监测气孔发育过程中生长素活性的动态变化。在不等分裂后较小的子细胞中生长素水平的降低预示着获得了保卫母细胞命运，其等分裂产生了两个保卫细胞。因此，气孔模式形成需要生长素途径控制干细胞区室的大小，以及生长素耗竭，触发从不等分裂到等分裂的发育开关。
