不对称
纤维素
细胞壁
生物物理学
手性(物理)
模数
作文(语言)
结晶学
材料科学
化学
物理
生物
复合材料
生物化学
手征对称性
量子力学
语言学
哲学
Nambu–Jona Lasinio模型
夸克
作者
Yin Chang,Rox Middleton,Yu Ogawa,Tom Gregory,Lisa Maria Steiner,Alexander Kovalev,Rebecca H N Karanja,Paula J. Rudall,Beverley J. Glover,Stanislav N. Gorb,Silvia Vignolini
标识
DOI:10.1073/pnas.2111723118
摘要
Chiral asymmetry is important in a wide variety of disciplines and occurs across length scales. While several natural chiral biomolecules exist only with single handedness, they can produce complex hierarchical structures with opposite chiralities. Understanding how the handedness is transferred from molecular to the macroscopic scales is far from trivial. An intriguing example is the transfer of the handedness of helicoidal organizations of cellulose microfibrils in plant cell walls. These cellulose helicoids produce structural colors if their dimension is comparable to the wavelength of visible light. All previously reported examples of a helicoidal structure in plants are left-handed except, remarkably, in the Pollia condensata fruit; both left- and right-handed helicoidal cell walls are found in neighboring cells of the same tissue. By simultaneously studying optical and mechanical responses of cells with different handednesses, we propose that the chirality of helicoids results from differences in cell wall composition. In detail, here we showed statistical substantiation of three different observations: 1) light reflected from right-handed cells is red shifted compared to light reflected from left-handed cells, 2) right-handed cells occur more rarely than left-handed ones, and 3) right-handed cells are located mainly in regions corresponding to interlocular divisions. Finally, 4) right-handed cells have an average lower elastic modulus compared to left-handed cells of the same color. Our findings, combined with mechanical simulation, suggest that the different chiralities of helicoids in the cell wall may result from different chemical composition, which strengthens previous hypotheses that hemicellulose might mediate the rotations of cellulose microfibrils.
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