Selective Excitation of Photosystems in Chloroplasts Inside Plant Leaves Observed by Near-Infrared Laser-Based Fluorescence Spectral Microscopy
Selective Excitation of Photosystems in Chloroplasts Inside Plant Leaves Observed by Near-Infrared Laser-Based Fluorescence Spectral Microscopy
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DOI：
10.1093/pcp/pcp182
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发表时间：
2010-02-01
影响因子：
4.9
通讯作者：
Kumazaki, Shigeichi
中科院分区：
文献类型：
--
作者：
Hasegawa, Makoto;Shiina, Takashi;Kumazaki, Shigeichi
在这项研究中，我们制作了植物叶绿体中的光系统的现场选择性图像。我们使用配备了近红外(NIR)激光的光谱成像显微镜，在室温下分析了玉米叶片的叶绿素自发荧光光谱和叶绿体图像。飞秒激光对叶肉细胞中叶绿体的激发显示出一种光谱形状，这是由于PSII及其位于基粒斑点中心的天线所致。我们发现，长达820 nm的近红外激光发射的连续波通过单光子吸收机制诱导了PSI对叶绿素自荧光的高贡献。因此，用连续波激光激发束鞘细胞中的叶绿体，获得了属于PSI及其天线的光谱形状。这些高纯度的光系统光谱被用来在每个叶绿体内空间进行光谱分解，以显示PSI和PSII及其相关天线的分布。描述了一种利用近红外激光在室温下检测叶片单个叶绿体中PSI/PSII比值的新方法。
In this study, we produced selective images of photosystems in plant chloroplasts in situ. We used a spectroimaging microscope, equipped with a near-infrared (NIR) laser that provided light at wavelengths mainly between 800 and 830nm, to analyze chlorophyll autofluorescence spectra and images from chloroplasts in leaves of Zea mays at room temperature. Femtosecond laser excitation of chloroplasts in mesophyll cells revealed a spectral shape that was attributable to PSII and its antenna in the centers of grana spots. We found that a continuous wave emitted by the NIR laser at a wavelength as long as 820nm induced chlorophyll autofluorescence with a high contribution from PSI through a one-photon absorption mechanism. A spectral shape attributable to PSI and its antenna was thus obtained using continuous wave laser excitation of chloroplasts in bundle sheath cells. These highly pure spectra of photosystems were utilized for spectral decomposition at every intrachloroplast space to show distributions of PSI and PSII and their associated antenna. A new methodology using an NIR laser to detect the PSI/PSII ratio in single chloroplasts in leaves at room temperature is described.