Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria.
Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland.
EMBO J. 2019 Apr 1;38(7). doi: 10.15252/embj.2018100353. Epub 2019 Mar 8.
Cellular elongation requires the defined coordination of intra- and extracellular processes, but the underlying mechanisms are largely unknown. The vacuole is the biggest plant organelle, and its dimensions play a role in defining plant cell expansion rates. Here, we show that the increase in vacuolar occupancy enables cellular elongation with relatively little enlargement of the cytosol in We demonstrate that cell wall properties are sensed and impact on the intracellular expansion of the vacuole. Using vacuolar morphology as a quantitative read-out for intracellular growth processes, we reveal that the underlying cell wall sensing mechanism requires interaction of extracellular leucine-rich repeat extensins (LRXs) with the receptor-like kinase FERONIA (FER). Our data suggest that LRXs link plasma membrane-localised FER with the cell wall, allowing this module to jointly sense and convey extracellular signals to the cell. This mechanism coordinates the onset of cell wall acidification and loosening with the increase in vacuolar size.
细胞伸长需要细胞内和细胞外过程的明确协调，但基本机制尚不清楚。液泡是植物最大的细胞器，其尺寸在确定植物细胞的扩展速率方面起着作用。在这里，我们表明，液泡占据空间的增加使得细胞伸长成为可能，同时细胞质的相对扩张较小。我们证明细胞壁特性被感知并影响液泡的细胞内扩展。使用液泡形态作为细胞内生长过程的定量读出，我们揭示了潜在的细胞壁感知机制需要细胞外富含亮氨酸重复的扩展蛋白（LRXs）与受体样激酶FERONIA（FER）的相互作用。我们的数据表明，LRXs 将质膜定位的 FER 与细胞壁连接起来，使这个模块能够共同感知并将细胞外信号传递到细胞。这种机制协调细胞壁酸化和松弛的开始与液泡大小的增加。
