Centre for Integrative Genomics, Faculty of Biology and Medicine, Génopode Building, University of Lausanne, 1015 Lausanne, Switzerland.
SIB, Swiss Institute for Bioinformatics, University of Lausanne, 1015 Lausanne, Switzerland.
Science. 2023 Nov 24;382(6673):935-940. doi: 10.1126/science.adh9384. Epub 2023 Nov 23.
In plants, light direction is perceived by the phototropin photoreceptors, which trigger directional growth responses known as phototropism. The formation of a phototropin activation gradient across a photosensitive organ initiates this response. However, the optical tissue properties that functionally contribute to phototropism remain unclear. In this work, we show that intercellular air channels limit light transmittance through various organs in several species. Air channels enhance light scattering in hypocotyls, thereby steepening the light gradient. This is required for an efficient phototropic response in and Brassica. We identified an embryonically expressed ABC transporter required for the presence of air channels in seedlings and a structure surrounding them. Our work provides insights into intercellular air space development or maintenance and identifies a mechanism of directional light sensing in plants.
在植物中，光的方向是由向光素光受体感知的，它会触发光取向生长反应。感光器官内形成的向光素激活梯度会引发这种反应。然而，对光取向反应有功能贡献的光学组织特性尚不清楚。在这项工作中，我们表明细胞间空气通道限制了多种物种中各种器官的光透过率。空气通道增强了下胚轴的光散射，从而使光梯度变陡。这对于 和 Brassica 的有效光取向反应是必需的。我们鉴定了一个胚胎表达的 ABC 转运蛋白，该蛋白对于幼苗中空气通道的存在及其周围结构是必需的。我们的工作提供了对细胞间空气空间发育或维持的深入了解，并确定了植物中定向光感测的机制。
