Abstract：
Cryptophytes are known to vary widely in coloration among species. These differences in color arise primarily from the presence of phycobiliprotein accessory pigments. There are nine defined cryptophyte phycobiliprotein (Cr-PBP) types, named for their wavelength of maximal absorbance. Because Cr-PBP type has traditionally been regarded as a categorical trait, there is a paucity of information about how spectral absorption characteristics of Cr-PBPs vary among species. We investigated variability in primary and secondary peak absorbance wavelengths and full width at half max (FWHM) values of spectra of Cr-PBPs extracted from 75 cryptophyte strains (55 species) grown under full spectrum irradiance. We show that there may be substantial differences in spectral shapes within Cr-PBP types, with Cr-Phycoerythrin (Cr-PE) 545 showing the greatest variability with two, possibly three, subtypes, while Cr-PE 566 spectra were the least variable, with only ±1 nm of variance around the mean absorbance maximum of 565 nm. We provide additional criteria for classification in cases where the wavelength of maximum absorbance alone is not definitive. Variations in spectral characteristics among strains containing the same presumed Cr-PBP type may indicate differing chromophore composition and/or the presence of more than one Cr-PBP in a single cryptophyte species.
摘要：
已知隐生植物在物种之间的颜色差异很大。这些颜色的差异主要来自藻胆蛋白辅助色素的存在。有九种确定的隐藻藻胆蛋白（Cr-PBP）类型，以其最大吸光度的波长命名。因为Cr-PBP类型传统上被认为是一种分类特征，关于Cr-PBP的光谱吸收特性在物种之间如何变化的信息很少。我们研究了从全谱辐照下生长的75种隐生植物菌株（55种）中提取的Cr-PBP光谱的主要和次要峰值吸收波长和半最大全宽（FWHM）值的变异性。我们表明，Cr-PBP类型的光谱形状可能存在实质性差异，Cr-藻红蛋白（Cr-PE）545显示出最大的变异性，其中两个，可能是三个,亚型，而Cr-PE566光谱变量最小，在565nm的平均吸光度最大值附近只有±1nm的方差。在单独的最大吸光度的波长不是确定的情况下，我们提供了其他分类标准。包含相同假定的Cr-PBP类型的菌株之间的光谱特征变化可能表明发色团组成不同和/或单个隐藻物种中存在多于一种Cr-PBP。
