Throughout 3.5 billion years of evolution, photosynthesis of land plants has developed a complicated antenna system to cope with the ever-changing environments. The antenna system of photosystem (PS) II includes the outer antennae and inner antennae. The inner antennae CP43 and CP47, located in the closest peripheral of PSII reaction center (RC), play important roles in facilitating excitation energy transport from the outer antennae to the PSII RC. Although PSII RC is the last station of energy transport, it is the inner antenna CP47, not the RC, which possesses the lowest energy level in PSII. Berteroa incana (B. incana), which is a vascular plant grown in the Gobi region, can sustain very high photosynthesis capacity under very high light conditions. It has been discovered that the thylakoid membrane of B. incana possesses a unique low fluorescence emission spectrum because the fluorescence emission of CP47 (695 nm) is the main fluorescence emission peak of PSII. In this paper, the thylakoid membrane, isolated from B. incana grown under a light condition of 100 μM photons m-2 s-1 and subjected to high light treatment (1600 μM photons m-2 s-1 for 1.5 h or 3 h) was employed for the research. It has been found that the high fluorescence emission of CP47 decreased remarkably upon exposure to the high light treatment. Further observation revealed that the drastic changes in the CP47 fluorescence emission were accompanied by a slight reduction in the amount of CP47 and an enhancement of the CP29-LHCII-CP24 assembly. It is proposed that CP47 enables the functional switch between the excitation energy transfer towards PSII RC, and the overexcitation quenching in the PSII core. Together with CP43, CP47 plays important roles in regulating excitation energy distribution in PSII core complexes.

中文翻译：

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光合内天线CP47在短命植物适应强光胁迫中起重要作用

在 35 亿年的进化过程中，陆地植物的光合作用已经形成了一个复杂的天线系统来应对不断变化的环境。光系统 (PS) II 的天线系统包括外天线和内天线。内触角 CP43 和 CP47 位于 PSII 反应中心 (RC) 最近的外围，在促进从外触角到 PSII RC 的激发能量传输方面发挥着重要作用。虽然 PSII RC 是能量传输的最后一站，但它是内部天线 CP47，而不是 RC，它在 PSII 中拥有最低的能量水平。Berteroa incana (B. incana) 是一种生长在戈壁地区的维管植物，可以在非常高的光照条件下维持非常高的光合作用能力。已经发现 B. incana 具有独特的低荧光发射光谱，因为 CP47 (695 nm) 的荧光发射是 PSII 的主要荧光发射峰。在本文中，从 B. incana 中分离的类囊体膜在 100 μM 光子 m-2 s-1 的光照条件下生长并经过强光处理（1600 μM 光子 m-2 s-1 1.5 h 或 3 h ) 被用于研究。已经发现，CP47 的高荧光发射在暴露于强光处理后显着降低。进一步观察表明，CP47 荧光发射的剧烈变化伴随着 CP47 数量的轻微减少和 CP29-LHCII-CP24 组装的增强。提出 CP47 可以实现激发能量转移到 PSII RC 之间的功能切换，和 PSII 核心中的过激淬灭。与 CP43 一起，CP47 在调节 PSII 核心复合物中的激发能分布方面发挥着重要作用。