TY - JOUR
T1 - Alternative methods for sampling and preservation of photosynthetic pigments and tocopherols in plant material from remote locations
AU - Esteban, Raquel
AU - Balaguer, Luis
AU - Manrique, Esteban
AU - Rubio de Casas, Rafael
AU - Ochoa, Raúl
AU - Fleck, Isabel
AU - Pintó-Marijuan, Marta
AU - Casals, Isidre
AU - Morales, Domingo
AU - Jiménez, MarıÃa Soledad
AU - Lorenzo, Roberto
AU - Artetxe, Unai
AU - Becerril, José María
AU - García-Plazaola, José Ignacio
PY - 2009
Y1 - 2009
N2 - Current methods for the study of pigments involve freezing in liquid nitrogen and storage at -80°C or lyophilization until HPLC analysis. These requirements greatly restrict ecophysiological research in remote areas where such resources are hardly available. We aimed to overcome such limitations by developing several techniques not requiring freezing or lyophilization. Two species with contrasting foliar characteristics (Olea europaea and Taraxacum officinale) were chosen. Seven preservation methods were designed, optimized and tested in a field trial. These protocols were compared with a control immediately frozen after collection. Pigments and tocopherols were analysed by HPLC. Main artefacts were chlorophyll epimerization or phaeophytinization, carotenoid isomerization, altered de-epoxidation index and tocopherol degradation. Among all methods, sample desiccation in silica gel provides robust samples (pigment composition was unaffected by storage time or temperature) and almost unaltered pigment profiles, except for a shift in epoxidation state. Although liquid nitrogen freezing and subsequent lyophilization or freezer storage were preferred, when these facilities are either not available or not suitable for long-distance transport, desiccation with silica gel, passive extraction in acetone and/or storage of fresh samples in water vapour saturated atmospheres enable a complete pigment characterization. Silica gel is advisable for long-term sample conservation.
AB - Current methods for the study of pigments involve freezing in liquid nitrogen and storage at -80°C or lyophilization until HPLC analysis. These requirements greatly restrict ecophysiological research in remote areas where such resources are hardly available. We aimed to overcome such limitations by developing several techniques not requiring freezing or lyophilization. Two species with contrasting foliar characteristics (Olea europaea and Taraxacum officinale) were chosen. Seven preservation methods were designed, optimized and tested in a field trial. These protocols were compared with a control immediately frozen after collection. Pigments and tocopherols were analysed by HPLC. Main artefacts were chlorophyll epimerization or phaeophytinization, carotenoid isomerization, altered de-epoxidation index and tocopherol degradation. Among all methods, sample desiccation in silica gel provides robust samples (pigment composition was unaffected by storage time or temperature) and almost unaltered pigment profiles, except for a shift in epoxidation state. Although liquid nitrogen freezing and subsequent lyophilization or freezer storage were preferred, when these facilities are either not available or not suitable for long-distance transport, desiccation with silica gel, passive extraction in acetone and/or storage of fresh samples in water vapour saturated atmospheres enable a complete pigment characterization. Silica gel is advisable for long-term sample conservation.
UR - http://handle.uws.edu.au:8081/1959.7/532331
U2 - 10.1007/s11120-009-9468-5
DO - 10.1007/s11120-009-9468-5
M3 - Article
VL - 101
SP - 77
EP - 88
JO - Photosynthesis Research
JF - Photosynthesis Research
IS - 1
ER -