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Nat Plants:英国学者揭示蓝叶子帮助植物在阴暗环境下生长

摘要 : 2016年10月19日,国际学术权威刊物自然出版集团旗下子刊《Nature Plants》在线发表了英国布里斯托大学Heather Whitney研究员的一篇研究论文,论文显示一种喜阴植物通过自己蓝晕色叶子,利用量子力学原理增强光合作用,从而适应了极度弱光的环境条件。

 2016年10月19日,国际学术权威刊物自然出版集团旗下子刊《Nature Plants》在线发表了英国布里斯托大学Heather Whitney研究员的一篇研究论文,论文显示一种喜阴植物通过自己蓝晕色叶子,利用量子力学原理增强光合作用,从而适应了极度弱光的环境条件。

叶绿体收集阳光并将其转化为植物的化学能,光照一开始被类囊体吸收,类囊体叠在一起形成不同大小的基粒。在马来西亚茂密热带雨林中发现的孔雀秋海棠(Begonia pavonina)拥有斑斓的蓝色叶子,因为它的表层具有不同寻常的叶绿体——虹光质体。

Heather Whitney及同事使用光镜和电镜研究孔雀秋海棠的虹光质体,发现它们的内部结构与传统叶绿体不同:它非常规则。虹光质体包含规则分布的3~4个类囊体形成的基粒,这些基粒像一个光学晶体,强烈反射430~560纳米波长的光,导致叶子呈蓝晕色。在马来西亚雨林中,能够抵达植物叶子的少量光主要是光谱中的红绿光谱的末端。




Photonic multilayer structure of Begoniachloroplasts enhances photosynthetic efficiency


Enhanced light harvesting is an area of interest for optimizing both natural photosynthesis and artificial solar energy capture1,2. Iridescence has been shown to exist widely and in diverse forms in plants and other photosynthetic organisms and symbioses3,4, but there has yet to be any direct link demonstrated between iridescence and photosynthesis. Here we show that epidermal chloroplasts, also known as iridoplasts, in shade-dwelling species of Begonia5, notable for their brilliant blue iridescence, have a photonic crystal structure formed from a periodic arrangement of the light-absorbing thylakoid tissue itself. This structure enhances photosynthesis in two ways: by increasing light capture at the predominantly green wavelengths available in shade conditions, and by directly enhancing quantum yield by 5–10% under low-light conditions. These findings together imply that the iridoplast is a highly modified chloroplast structure adapted to make best use of the extremely low-light conditions in the tropical forest understorey in which it is found5,6. A phylogenetically diverse range of shade-dwelling plant species has been found to produce similarly structured chloroplasts7,​8,​9, suggesting that the ability to produce chloroplasts whose membranes are organized as a multilayer with photonic properties may be widespread. In fact, given the well-established diversity and plasticity of chloroplasts10,11, our results imply that photonic effects may be important even in plants that do not show any obvious signs of iridescence to the naked eye but wher a highly ordered chloroplast structure may present a clear blue reflectance at the microscale. Chloroplasts are generally thought of as purely photochemical; we suggest that one should also think of them as a photonic structure with a complex interplay between control of light propagation, light capture and photochemistry.

来源: Nature Plants 浏览次数:0


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