Department of Biological Sciences, Wellesley College;
Department of Biological Sciences, Wellesley College.
J Vis Exp. 2021 Jul 14(173). doi: 10.3791/62881.
Chloroplast movement in leaves has been shown to help minimize photoinhibition and increase growth under certain conditions. Much can be learned about chloroplast movement by studying the chloroplast positioning in leaves using e.g., confocal fluorescence microscopy, but access to this type of microscopy is limited. This protocol describes a method that uses the changes in leaf transmission as a proxy for chloroplast movement. If chloroplasts are spread out in order to maximize light interception, the transmission will be low. If chloroplasts move towards the anticlinal cell walls to avoid light, the transmission will be higher. This protocol describes how to use a straightforward, home-built instrument to expose leaves to different blue light intensities and quantify the dynamic changes in leaf transmission. This approach allows researchers to quantitatively describe chloroplast movement in different species and mutants, study the effects of chemicals and environmental factors on it, or screen for novel mutants e.g., to identify missing components in the process that leads from light perception to the movement of chloroplasts.
叶绿体在叶片中的运动被证明有助于在某些条件下最小化光抑制并促进生长。通过例如共聚焦荧光显微镜研究叶片中叶绿体的定位，可以了解很多关于叶绿体运动的知识，但这种显微镜的使用受到限制。本方案描述了一种使用叶片透过率变化来替代叶绿体运动的方法。如果叶绿体为了最大程度地吸收光线而展开，那么透过率将会较低。如果叶绿体向垂周壁移动以避免光线，那么透过率将会较高。本方案描述了如何使用简单的自制仪器来使叶片暴露于不同的蓝光强度下，并定量测量叶片透过率的动态变化。这种方法使研究人员能够在不同物种和突变体中定量描述叶绿体的运动，研究化学物质和环境因素对其的影响，或者筛选新型突变体，例如，确定从光感知到叶绿体运动过程中缺失的成分。
