School of Biological Sciences, Universiti Sains Malaysia, Gelugor, Pulau Pinang, Malaysia.
School of Pharmaceutical Sciences, Universiti Sains Malaysia, Gelugor, Pulau Pinang, Malaysia.
PLoS One. 2018 Apr 12;13(4):e0195642. doi: 10.1371/journal.pone.0195642. eCollection 2018.
Anoectochilus sp. and Ludisia discolor are known as Jewel orchids. Both species are terrestrial wild orchids that grow in shaded areas of forests. The Jewel orchids are renowned for the beauty of their leaves, which are dark-green laced with silvery or golden veins. The orchids are used as a cure in various parts of Asia. Overharvesting and anthropogenic disturbances threaten the existence of the Jewel orchids in the wild, necessitating human intervention in their survival. An understanding of the structure and adaptations of a plant may assist in its survival when propagated outside of its habitat. In this study, ex vitro leaves of Anoectochilus sp. and L. discolor were subjected to freehand sectioning, and then inspected through brightfield and fluorescence microscopy. The study indicated that all parts of both plants presented typical monocotyledonous characteristics except the leaves. The leaves displayed dorsiventrality with distinct palisade and spongy mesophyll layers. The spongy mesophyll layer contained cells which fluoresced a bright red when exposed to ultraviolet, blue, and green light wavelengths, hinting at the presence of anthocyanins for photoprotection. Cyanidin was detected in the leaves of L. discolor, as enumerated through high performance liquid chromatography (HPLC). The observations indicated that Anoectochilus sp. and L. discolor are well-adapted to live under shaded conditions with minimal exposure to light.
斑叶兰和大斑叶兰被称为宝石兰。这两个物种都是生长在森林阴暗处的陆生野生兰花。宝石兰以其深绿色叶片上的银色或金色叶脉为特色而闻名。这些兰花在亚洲的许多地方都被用作药物。过度采挖和人为干扰威胁着野生宝石兰的生存，需要人类干预以确保其生存。了解植物的结构和适应性可能有助于在其栖息地之外进行繁殖时提高其存活率。在这项研究中，我们对斑叶兰和大斑叶兰的离体叶片进行徒手切片，然后通过明场和荧光显微镜进行观察。研究表明，除了叶片之外，这两种植物的所有部分都呈现出典型的单子叶植物特征。叶片表现出背腹性，具有明显的栅栏组织和海绵状叶肉层。海绵状叶肉层中的细胞在暴露于紫外线、蓝光和绿光时会发出鲜艳的红色荧光，这表明为了光保护存在类黄酮。通过高效液相色谱法（HPLC）检测到大斑叶兰叶片中存在飞燕草素。这些观察结果表明，斑叶兰和大斑叶兰适应在光照最少的阴暗条件下生存。
