Effects of epidermal cell shape and pigmentation on optical properties of Antirrhinum petals at visible and ultraviolet wavelengths
Effects of epidermal cell shape and pigmentation on optical properties of Antirrhinum petals at visible and ultraviolet wavelengths
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DOI：
10.1104/pp.112.3.879
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发表时间：
1996-11-01
期刊：
影响因子：
7.4
通讯作者：
Vogelmann, TC
中科院分区：
文献类型：
--
作者：
Gorton, HL;Vogelmann, TC
本文以大鼻炎（Antirrhinum majus）的Mixta（+）和Mixta（-）系为模型系统，研究了表皮细胞形状和色素沉着对可见和紫外光谱区组织光学特性的影响。Mixta（+）花的正面表皮细胞具有圆锥状乳头状；在混合（-）细胞系中，细胞略呈圆顶状。无论在高紫外线还是低紫外线条件下，Mixta（+）细胞中花青素和其他类黄酮含量均显著高于Mixta（-）细胞。Mixta（+）细胞将光聚焦在其色素内部（3.5-4.7倍入射），而Mixta（-）细胞将光聚焦在未着色的叶肉（2.1-2.7倍入射）。紫外光穿透表皮（通常在312 nm处透光率为20-50%），主要通过两系相似的细胞无色素的外周区域，因此通过Mixta（+）和Mixta（-）表皮的总体穿透力相等。但是，Mixta（+）在表皮细胞中心区域的最大紫外吸收量略大于Mixta(-)，并且完整的Mixta（+）花在类黄酮吸收中等的光谱区域反射的光较少。在这两种情况下，大约50%到75%的差异可归因于细胞形状以及由此导致的光路长度或聚焦的变化。
We used the Mixta(+) and mixta(-) lines of Antirrhinum majus as a model system to investigate the effects of epidermal cell shape and pigmentation on tissue optical properties in the visible and ultraviolet (UV) spectral regions. Adaxial epidermal cells of Mixta(+) flowers have a conical-papillate shape; in the mixta(-) line the cells are slightly domed. Mixta(+) cells contained significantly more anthocyanin and other flavonoids than mixta(-) cells when plants were grown under either high- or low-UV conditions. Mixta(+) cells focused light (3.5-4.7 times incident) within their pigmented interiors, whereas mixta(-) cells focused light (2.1-2.7 times incident) in the unpigmented mesophyll. UV light penetrated the epidermis (commonly 20-50% transmittance at 312 nm) mainly through the unpigmented peripheral regions of the cells that were similar for the two lines, so that overall penetration through Mixta(+) and mixta(-) epidermises was equal. However, maximum UV absorption in the central region of epidermal cells was slightly greater in Mixta(+) than mixta(-), and intact Mixta(+) flowers reflected less light in the spectral regions with intermediate flavonoid absorbance. In both cases, about 50 to 75% of the difference could be attributed to cell shape and resulting changes in the optical pathlength or focusing.