据介绍，在植物中，光的方向由趋光素光感受器感知，从而触发被称为向光性的定向生长反应。在光敏器官上形成的向光蛋白激活梯度启动了这种反应。然而，在功能上有助于向光性的光学组织特性仍不清楚。
在这项工作中，研究人员发现细胞间的空气通道限制了几种物种通过各种器官的透光率。空气通道增强了拟南芥下胚轴的光散射，从而使光梯度变陡。这是拟南芥和芸苔属中有效的向光反应所必需的。研究人员鉴定了一种胚胎表达的ABC转运蛋白，它是幼苗中存在空气通道所必需的，也是它们周围的结构。
总之，这一工作为细胞之间空气空间的发展或维持提供了见解，并确定了植物定向光传感的机制。
附：英文原文
Title: Air channels create a directional light signal to regulate hypocotyl phototropism
Author: Ganesh M. Nawkar, Martina Legris, Anupama Goyal, Emanuel Schmid-Siegert, Jérémy Fleury, Antonio Mucciolo, Damien De Bellis, Martine Trevisan, Andreas Schueler, Christian Fankhauser
Issue&Volume: 2023-11-24
Abstract: 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 Arabidopsis hypocotyls, thereby steepening the light gradient. This is required for an efficient phototropic response in Arabidopsis 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.
DOI: adh9384
Source: https://www.science.org/doi/10.1126/science.adh9384