AOBPreview originally published online on August 25, 2004
Annals of Botany 2004 94(4):615-621; doi:10.1093/aob/mch181
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Annals of Botany 94/4, © Annals of Botany Company 2004; all rights reserved
Amino Acids Composition of Teucrium Nutlet Proteins and their Systematic Significance
1 Department of Plant Biology and Ecology, University of Sevilla, 41012-Sevilla, Spain and 2 Instituto de la Grasa, Padre García Tejero 4, 41012-Sevilla, Spain
* For correspondence. E-mail jpastor{at}us.es
Received: 24 December 2003 Returned for revision: 13 May 2004 Accepted: 1 July 2004 Published electronically: 25 August 2004
Background and Aims Plant species are considered as a good source of dietary proteins, although the nutritional quality of proteins depends on their amino acid composition. In this work the protein content and amino acid composition of nutlets of 21 Teucrium taxa (Lamiaceae) from Spain were analysed and their nutritional quality was compared with the minimum values established by the Food and Agriculture Organization of the United Nations (FAO). In addition, the amino acid composition was evaluated as a chemical character to clarify the taxonomic complexity in this genus.
Methods Amino acid content of nutlets was determined after derivatization with diethyl ethoxymethylenemalonate by high-performance liquid chromatography. Previously, nutlets samples were hydrolysed and incubated in an oven at 110 °C for 24 h.
Key Results The protein content was variable, ranging from 6·4 % in T. dunense to 43·8 % in T. algarbiense. According to the FAO values all taxa contain satisfactory amounts of leucine, threonine and valine and are deficient in lysine. The similarity analysis of Teucrium taxa using amino acid composition data did not clearly reflect the infrageneric classification of this genus.
Conclusions Annual species, such as T. spinosum, T. aristatum and T. resupinatum showed a better balanced amino acid composition. The dendrogram partly matched with the karyological complexity of Teucrium. No correlation between amino acid composition and habitat has been observed, showing that Teucrium nutlet amino acid composition may not be strongly influenced by the environment.
Key words: Teucrium, Lamiaceae, nutlets, protein, amino acids, taxonomy, karyology